2021 Volume 32 Issue 1

Diverse synthesis of the C ring fragment of bryostatins via Zn/Cu-promoted conjugate addition of α-hydroxy iodide with enone
Zhiwen Chu , Ruiqi Tong , Yufan Yang , Xuanyi Song , Tian bao Hu , Yu Fan , Chen Zhao , Lu Gao , Zhenlei Song
2021, 32(1): 1-4  doi: 10.1016/j.cclet.2020.11.039
[Abstract](239) [FullText HTML] [PDF 891KB](11)
A convergent approach to 1,5-hydroxy ketones, the general precursors for constructing the C ring of bryostatins, has been developed via a Zn/Cu-promoted conjugate addition of α-hydroxy iodides with enones. The reaction leads to direct formation of the C21-C22 bond and tolerates diverse functionalities at the C17-, C18- and C24-positions. The approach also enables a more concise synthesis of the known C ring intermediate (10 longest linear steps and 14 total steps), in contrast to its previous synthesis (17 longest linear steps and 22 total steps) in our total synthesis of bryostatin 8.
Directly conversion the biomass-waste to Si/C composite anode materials for advanced lithium ion batteries
Qiang Ma , Yu Dai , Hongrui Wang , Guozhu Ma , Hui Guo , Xianxiang Zeng , Naimei Tu , Xiongwei Wu , Mingtao Xiao
2021, 32(1): 5-8  doi: 10.1016/j.cclet.2020.11.007
[Abstract](234) [FullText HTML] [PDF 932KB](5)
The necessity to explore high-efficiency and high-value utilization strategy for biomass-waste is desirable. Herein, the strategy for direct conversion biomass-waste (rice husks) to Si/C composite structure anode was built. The Si/C composite materials were successfully obtained via the typical thermal reduction with magnesium, and the Si nanoparticle was uniformly embedded in carbon frame, as revealed by Raman, X-ray diffraction (XRD) and transmission electron microscope (TEM) measurement. The carbon structure among rice husks was effectively used as a protective layer to accommodate the volume variation of Si anode during the repeated lithiation/delithiation process. Benefitting from the structure design, the batteries show a superior electrochemical stability with the capacity retention rate above 90% after 150 cycles at the charge/discharge rate of 0.5 C (1 C = 600 mAh/g), and hold a high charge capacity of 420.7 mAh/g at the rate of 3 C. Therefore, our finding not only provides a promising design strategy for directly conversion biomass-waste to electrochemical storage materials but broadens the high-efficiency utilization method for other biomass by-products.
Mechanism and selectivity of copper-catalyzed borocyanation of 1-aryl-1,3-butadienes: A computational study
Xinzhi Li , Xiangwei Ren , Hongli Wu , Wentao Zhao , Xiangyang Tang , Genping Huang
2021, 32(1): 9-12  doi: 10.1016/j.cclet.2020.11.045
[Abstract](225) [FullText HTML] [PDF 869KB](3)
Density functional theory calculations have been performed to investigate the copper-catalyzed borocyanation of 1-aryl-1,3-butadienes. The computations show that the regio- and enantioselectivity is determined by the borocupration step. The π-electron withdrawing aryl group at the C1 atom makes the C4 atom more electrophilic than the other carbon atoms, which together with the steric repulsion around the forming C—B bond, results in the experimentally observed exclusive 4,3-regioselectivity. The origins of the enantioselectivity were attributed to the steric effect and π-π stacking interaction between the butadiene moiety and the ligand.
In-situ electro-deposition synthesis of MnOx-NiCo2O4 monolithic catalyst with rich phase interfaces
Dongdong Wang , Yingchao Du , Xiaoze Wang , Zhaxi Cuo , Yunfa Chen
2021, 32(1): 21-24  doi: 10.1016/j.cclet.2020.11.012
[Abstract](111) [FullText HTML] [PDF 835KB](2)
A hierarchically structured MnOx-NiCo2O4 monolithic catalyst with rich phase interfaces was designed by a simple, eco-friendly and time-saving in-situ electro-deposition method. The abundance of active oxygen species due to this rich phase interfaces contributed to the excellent benzene combustion performance of MnOx-NiCo2O4-2:2 sample, oxidizing about 90% of benzene (T90) at 198 ℃ under 12000 h-1 gaseous hourly space velocity. This work shed new light on the design of excellent monolithic catalysts, which might pave the way for the industrialization of benzene combustion.
Aconapelsulfonines A and B, seco C20-diterpenoid alkaloids deriving via Criegee rearrangements of napelline skeleton from Aconitum carmichaelii
Hui Liu , Yuzhuo Wu , Qinglan Guo , Shuai Shao , Chengbo Xu , Tiantai Zhang , Jiangong Shi
2021, 32(1): 33-36  doi: 10.1016/j.cclet.2020.09.062
[Abstract](191) [FullText HTML] [PDF 818KB](1)
Two sulfonated seco C20-diterpenoid alkaloids, aconapelsulfonines A (1) and B (2), were isolated from an aqueous extract of the raw material of "Fu Zi" (the Aconitum carmichaelii lateral roots), of which the structures were elucidated by various spectroscopic data, combined with X-ray crystallographic analysis. The unprecedented skeletons are biogenetically proposed to be derived via Criegee rearrangements of the napelline-type architecture. The two compounds exhibited dose-depended analgesic activities on an acetic acid-induced mice writhing test.
An unexpected iron(Ⅱ)-promoted reaction of N-arylprop-2-yn-1-imines with water: Facile assembly of multi-substituted pyrroles
Kaida Zhou , Jiapian Huang , Jie Wu , Guanyinsheng Qiu
2021, 32(1): 37-39  doi: 10.1016/j.cclet.2020.11.049
[Abstract](231) [FullText HTML] [PDF 750KB](7)
Generation of multi-substituted pyrroles is accomplished through an unexpected iron(Ⅱ)-promoted reaction of N-arylprop-2-yn-1-imines with water. This transformation proceeds smoothly with excellent chemoselectivity and regioselectivity. A stoichiometric amount of Fe(OTf)2 is necessary for the successful conversion. A Lewis acid-promoted tandem reaction pathway is proposed.
Low-temperature and stable CO oxidation of Co3O4/TiO2 monolithic catalysts
Xinyue Tang , Junchao Wang , Yonghui Ma , Jing Li , Xinglai Zhang , Baodan Liu
2021, 32(1): 48-52  doi: 10.1016/j.cclet.2020.11.008
[Abstract](202) [FullText HTML] [PDF 1062KB](2)
Highly efficient Co3O4/TiO2 monolithic catalysts with enhanced stability were in-situ grown on Ti mesh for CO oxidation, which could completely oxidize CO at 120 ℃. The comprehensive catalytic performance is competitive to some noble metal catalysts and conventional Co3O4 powder catalysts, which holds great potential toward industrial applications. Meanwhile, the in-situ synthesis strategy of Co3O4/TiO2 monolithic catalysts on flexible mesh substrate in this work can be extended to the development of a variety of oxide-based monolithic catalysts towards diverse catalysis applications.
Potential active sites of Mo single atoms for electrocatalytic reduction of N2
Lei Chen , Chaozheng He , Ran Wang , Qian Li , Jian Zeng , Wei Liu , Yuchao Wang , Qichen Wang , Tong Ye , Yougen Tang , Yongpeng Lei
2021, 32(1): 53-56  doi: 10.1016/j.cclet.2020.11.013
[Abstract](256) [FullText HTML] [PDF 846KB](4)
Single atom catalysts (SACs) with isolated metal atoms dispersed on supports exhibit distinctive performances for electrocatalysis reactions. The designable realization of well-dispersed single metal atoms is still a great challenge owing to their ease of aggregation. Here, Mo single atomic sites (Mo-N3C) combined with some ultrasmall Mo2C/MoN clusters (Mo-SA/Mo2C-MoN-Cs, mean diameter < 2 nm) on nitrogen-doped porous carbon were synthesized via a simple pyrolysis of bimetallic Zn/Mo metal-organic frameworks. X-ray absorption near edge spectra (XANES) in combination with various characterizations show that most of Mo species in sample exist in the form of single sites and the exact structure is Mo-N3C. Density functional theory (DFT) calculation further shows that as the number of N-coordination in the Mo-NxC moieties increases, the positive charge of Mo atoms increases. The single Mo atoms in Mo-N3C have the best capability of N2 adsorption, which may serve as main active sites for further electrochemical N2 reduction.
Construction and investigation of photo-switch property of azobenzene-bridged pillar[5]arene-based [3]rotaxanes
Hui Chong , Cuiyun Nie , Lihong Wang , Sicong Wang , Ying Han , Yang Wang , Chengyin Wang , Chaoguo Yan
2021, 32(1): 57-61  doi: 10.1016/j.cclet.2020.11.020
[Abstract](242) [FullText HTML] [PDF 945KB](6)
Series of azobenzene-bridged pillar[5]arene-based [3]rotaxanes with different alkyl chain length of guest molecules were constructed by threading-endcapping method with alkylenetriazole as axile and tetrahydrochromene as endcapping group. The encapsulation of pillar[5]arenes were proved by high-resolution mass, 1H NMR and NOESY spectra. The photo-responsive property were examined by irradiation of the synthesized [3]rotaxanes with 365 nm and blue light LED, which caused trans to cis and cis to trans isomerization, respectively. Irradiation of corresponding model guest compounds without pillar[5]arene encapsulation resulted in near completely trans to cis and cis to trans isomerization, indicating the existence of pillar[5]arenes is the determining factor for the comprised photo isomerization efficiency.
Co-NC as adsorbent and matrix providing the ability of MALDI MS to analyze volatile compounds
Shumu Li , Jian'an Liu , Jiping Sun , Zhenpeng Wang , Kai Wang , Lei Guo , Shuliang Yang , Jinchao Wei , Xiangjun Zheng , Zhenwen Zhao
2021, 32(1): 62-65  doi: 10.1016/j.cclet.2020.09.026
[Abstract](241) [FullText HTML] [PDF 849KB](3)
Traditional matrix does not allow matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) to analyze volatile compounds, because volatile analytes may vaporize during the sample preparation process or in the high vacuum circumstance of ion source. Herein, we reported a Co and N doped porous carbon material (Co-NC) which were synthesized by pyrolysis of a Schiff base coordination compound. Co-NC could simultaneously act as adsorbent of volatile compounds and as matrix of MALDI MS, to provide the capability of MALDI MS to analyze volatile compounds. As adsorbent, Co-NC could strongly adsorb and enrich the volatile compounds in perfume and herbs, and hold them even in the high vacuum circumstance. On the other hand, Co-NC could absorb the energy of the laser, and then transfer the energy to the analyte for desorption and ionization of analyte in both negative and positive ionization modes. Additionally, the background interferences were avoided in the low-mass region (< 500 Da) when using Co-NC as matrix, overcoming the challenges of MALDI MS analysis of small molecule compounds. In summary, Co-NC as matrix tremendously extended the application of MALDI MS.
Establishment of a new molecular model for mercury determination verified by single crystal X-ray diffraction, spectroscopic analysis and biological potentials
Jiapei Gu , Feifan Zhang , Ziman Zheng , Xiangqian Li , Runxuan Deng , Zhan Zhou , Lufang Ma , Wanqiang Liu , Qianming Wang
2021, 32(1): 87-91  doi: 10.1016/j.cclet.2020.09.021
[Abstract](240) [FullText HTML] [PDF 912KB](1)
A wide variety of molecular probes have been developed for real-time analysis, but most of organic fluorophores possess small Stokes shifts and self-absorption or inner filter effect that could not be avoided. In this study, a new dicyanoisophorone-based derivative (E)-O-(4-(2-(3-(dicyanomethylene)-5, 5-dimethylcyclohex-1-en-1-yl)vinyl)phenyl)diphenylphosphinothioate (λex = 405 nm, λem = 551 nm, denoted as ICM-S) with strong push-pull electron effect has been afforded and it exhibits red shift for absorption from 407 nm to 426 nm with distinct color change from pale yellow to deep yellow upon exposure to Hg2+. Moreover, an easily distinguishable fluorescence color change follows the route from green, yellow to red in the presence of Hg2+ over the range of 0-90 μmol/L (detection limit = 137 nmol/L) can be observed by the naked eye under a UV lamp irradiation. Chlorodiphenylphosphine and sublimed-sulfur are incorporated as responsive sites and P-O bond has been cleaved upon the addition of mercury ions. During the recognition process, such dicyanoisophorone dye (ICM-S) has been evolved to 2-(3-(4-hydroxystyryl)-5, 5-dimethylcyclohex-2-enylidene) malononitrile (ICM OH). Clear evidences in the chemical processes can be identified via single crystal X-ray diffraction, spectroscopic analysis, photophysical studies and titration experiments. With the aim of exploring its potential in biological systems, its in vitro responses to Hg2+ have been evaluated in 293 Tcells and the effectiveness in zebrafish model has also been verified.
Biomass-derived nitrogen self-doped porous activation carbon as an effective bifunctional electrocatalysts
Yuanqing Sun , Yiming Ouyang , Jiaqing Luo , Huihui Cao , Xiang Li , Jingwen Ma , Jian Liu , Yuanhao Wang , Lin Lu
2021, 32(1): 92-98  doi: 10.1016/j.cclet.2020.09.027
[Abstract](234) [FullText HTML] [PDF 1087KB](3)
The strategy of adopting cheap precursors or abundant resources, which can be obtained directly from nature, is a simple and excellent method of introducing accessible research into environmentally friendly development. Moreover, this is also an urgent requirement for the sustainable development of green technology. Herein, we introduce a simplistic and expandable method to prepare metal-free biomass-derived nitrogen self-doped porous activation carbon (N-PAC) with large specific surface area (SBET = 1300.58 m2/g). Moreover, the manufactural electrocatalysts exhibit prominent oxygen reduction reaction (ORR) performance in all PH values. As compared with the commercial Pt/C catalyst, the N-PAC/800 with a positive onset potential at 10 mA/cm2 (0.93 V), half-wave potential (0.87 V), and limiting current (6.34 mA/cm2) bring to light excellent catalytic stability, selectivity, and much-enhanced methanol tolerance. Furthermore, the prepared electrocatalysts possess considerable hydrogen evolution reaction (HER) performance with a less onset potential of 0.218 V (acidic medium) and 0.271 V (alkaline medium) respectively, which can show similar catalytic activity across the whole pH range. Such bifunctional electrocatalyst, with excellent electrocatalytic properties, resource-rich, low cost, and environmental-friendly, hold a promising application in energy conversion and reserve.
A novel polyethyleneimine-decorated FeOOH nanoparticle for efficient siRNA delivery
Shuai Guo , Bei Liu , Mengjie Zhang , Chunhui Li , Xiaoxia Wang , Yuhua Weng , Lele Li , Yuanyu Huang
2021, 32(1): 102-106  doi: 10.1016/j.cclet.2020.11.024
[Abstract](275) [FullText HTML] [PDF 1063KB](5)
Despite the promising prospect of small interfering RNA (siRNA) for the treatment of diverse diseases, it remains challenging to develop novel delivery materials to desired tissues and cells. In this study, a novel iron oxyhydroxide (FeOOH) nanoparticle (NP) whose surface was modified with branched polyether-imide (PEI) was developed to deliver siRNA into the cancer cells. It was demonstrated that PEI-FeOOH (PFeOOH) efficiently complexed siRNA, mediated effective cellular uptake and endosomal escape, thereby triggering robust gene silencing in vitro. In addition, PFeOOH/siRNA formulation loading with anti-RRM2 siRNA effectively inhibited the growth of tumor tissues, and exhibited excellent safety profiles in vivo. Therefore, this study conceptually provided a FeOOH-based nucleic acid delivery vesicle which can potentially use to achieve diagnosis and therapy simultaneously.
Stable hydrazone-linked chiral covalent organic frameworks: Synthesis, modification, and chiral signal inversion from monomers
Yilun Yan , Xinle Li , Gui Chen , Kai Zhang , Xihao Tang , Shuyuan Zhang , Shengrun Zheng , Jun Fan , Weiguang Zhang , Songliang Cai
2021, 32(1): 107-112  doi: 10.1016/j.cclet.2020.11.063
[Abstract](262) [FullText HTML] [PDF 1057KB](6)
The designed synthesis of chiral covalent organic frameworks (COFs) featuring intriguing properties is fairly scant and remains a daunting synthetic challenge. Here we develop a de novo synthesis of an enantiomeric pair of 2D hydroxyl-functionalized hydrazone-linked chiral COFs, (S)- and (R)-HthBta-OH COFs, using enantiopure 2, 5-bis(2-hydroxypropoxy)terephthalohydrazide (Hth) as monomers. The formation process of hydroxyl-functionalized chiral COFs was monitored using rigorous time-dependent PXRD, vibrational circular dichroism (VCD), and electronic circular dichroism (ECD) studies. Remarkably, VCD spectra indicated a unique chiral signal inversion from the positive Cotton effect of (S)-Hth monomer to the negative Cotton effect of (S)-HthBta-OH COF, which has never been reported in chiral COFs. Moreover, two unprecedented carboxyl-functionalized chiral COFs, (S)- and (R)-HthBta-COOH, were constructed by a post-synthetic modification of the corresponding hydroxyl chiral COFs with succinic anhydride. Notably, carboxyl-functionalized COFs retained homochirality and crystallinity without linker racemization and structural collapse after the chemical modification due to the chemically robust nature of pristine hydrazone-linked chiral COFs.
Synthesis of iron oxide cubes/reduced graphene oxide composite and its enhanced lithium storage performance
Chenran Hao , Tiange Gao , Anbao Yuan , Jiaqiang Xu
2021, 32(1): 113-118  doi: 10.1016/j.cclet.2020.11.038
[Abstract](208) [FullText HTML] [PDF 1090KB](2)
Fe3O4 is considered as a promising electrode material for lithium-ion batteries (LIBs) due to its low cost and high theoretical capacity (928 mAh/g). Nevertheless, the huge volume expansion and poor conductivity seriously hamper its practical applications. In this study, we use a facile hydrothermal reaction together with a post heat treatment to construct the three-dimensional heterostructured composite (Fe3O4/rGO) inwhich reduced graphene oxide sheets wraped the Fe3O4 submicron cubes as the conductive network. The electric conduction and electrode kinetics of lithium ion insertion/ extraction reaction of the composite is enhanced due to the assist of conductive rGO, and thus the Li-storage performance is obviously improved. The composite exhibits a reversible charge capacity of 772.1 mAh/g at the current density of 0.1 A/g, and the capacity retention reaches 70.3% after 400 cycles at 0.5 A/g, demonstrating obviously higher specific capacity and rate capability over the Fe3O4 submicron cubes without rGO, and much superior cycling stability to the parent Fe2O3 submicron cubes without rGO. On the other hand, as a synergic conductive carbon support, the flexible rGO plays an important role in buffering the large volume change during the repeated discharge/charge cycling.
Metal-organic framework derived NiCoP hollow polyhedrons electrocatalyst for pH-universal hydrogen evolution reaction
Yunrui Wei , Xixi Zhang , Zonghua Wang , Jiangmei Yin , Jinzhao Huang , Gang Zhao , Xijin Xu
2021, 32(1): 119-124  doi: 10.1016/j.cclet.2020.10.046
[Abstract](305) [FullText HTML] [PDF 1036KB](2)
Hollow nanostructures have attracted increasing research interest in hydrogen evolution reaction owing to their unique structural features. Herein, Ni–Co mixed metal phosphide hollow and porous polyhedrons was successfully composited (expressed as NiCoP). Benefiting from the synergistic effects of ZIF-67 by doping Ni elements and the well-defined hollow and porous structure, the as-synthesized NiCoP hollow and porous polyhedrons exhibit better electrochemical properties and mechanical stability for hydrogen evolution reaction over a pH-universal range, with a small Tafel slopes of 72, 101, 176 mV/dec, and a low overpotential of 82, 102, 261 mV at a current density of 10 mA/cm2 in 0.5 mol/L H2SO4, 1 mol/L KOH and 1 mol/L phosphate buffer solution (PBS). This general strategy can also be applied to fabricate other hollow cobalt-based phosphides and MOFs-derived materials for HER.
Asymmetric double-layer composite electrolyte with enhanced ionic conductivity and interface stability for all-solid-state lithium metal batteries
Binglu Zhao , Luxiang Ma , Kai Wu , Mengxiong Cao , Minggui Xu , Xinxiang Zhang , Wen Liu , Jitao Chen
2021, 32(1): 125-131  doi: 10.1016/j.cclet.2020.10.045
[Abstract](282) [FullText HTML] [PDF 1029KB](7)
All-solid-state Li metal battery has been regarded as a promising battery technology due to its high energy density based on the high capacity of lithium metal anode and high safety based on the all solid state electrolyte without inflammable solvent. However, challenges still exist mainly in the poor contact and unstable interface between electrolyte and electrodes. Herein, we demonstrate an asymmetric design of the composite polymer electrolyte with two different layers to overcome the interface issues at both the cathode and the anode side simultaneously. At the cathode side, the polypropylene carbonate layer has enough viscosity and flexibility to reduce the inter-facial resistance, while at the Li anode side, the polyethylene oxide layer modified with hexagonal boron nitride has high mechanical strength to suppress the Li dendrite growth. Owing to the synergetic effect between different components, the as-prepared double layer composite polymer electrolyte demonstrates a large electrochemical window of 5.17 V, a high ionic conductivity of 6.1×10-4 S/cm, and a transference number of 0.56, featuring excellent ion transport kinetics and good chemical stability. All-solid-state Li metal battery assembled with LiFePO4 cathode and Li anode delivers a high capacity of 150.9 mAh/g at 25 ℃ and 0.1 C-rate, showing great potential for practical applications.
Multisubstituted pyrazole synthesis via [3 + 2] cycloaddition/rearrangement/N—H insertion cascade reaction of α-diazoesters and ynones
Peng Zhao , Zi Zeng , Xiaoming Feng , Xiaohua Liu
2021, 32(1): 132-135  doi: 10.1016/j.cclet.2020.11.053
[Abstract](226) [FullText HTML] [PDF 834KB](4)
The cascade reactions of alkyl α-diazoesters and ynones using Al(OTf)3 as the catalyst are described. A series of 4-substituted pyrazoles were obtained via [3 + 2] cycloaddition, 1, 5-ester shift, 1, 3-H shift, and N—H insertion process. Deuterium labelling experiments, kinetic studies and control experiments were carried out for the rationalization of the mechanism.
Catalyst- and additive-free selective sulfonylation/cyclization of 1,6-enynes with arylazo sulfones leading to sulfonylated γ-butyrolactams
Qishun Liu , Yufen Lv , Ruisheng Liu , Xiaohui Zhao , Jiawen Wang , Wei Wei
2021, 32(1): 136-139  doi: 10.1016/j.cclet.2020.11.059
[Abstract](241) [FullText HTML] [PDF 806KB](3)
A convenient and regioselective sulfonylation/cyclization of 1,6-enynes with arylazo sulfones has been developed to access a series of sulfonylated γ-butyrolactams. The present reaction could be efficiently conducted under catalyst- and additive-free conditions, in which C—S and C—C bonds were selectively constructed in one-pot procedure.
Synthesis of an ordered porous carbon with the dual nitrogen-doped interfaces and its ORR catalysis performance
Hongwei Zhao , Yanqiu Zhang , Li Lixiang , Xin Geng , Haiming Yang , Weimin Zhou , Chengguo Sun , Baigang An
2021, 32(1): 140-145  doi: 10.1016/j.cclet.2020.11.035
[Abstract](217) [FullText HTML] [PDF 987KB](3)
Both nitrogen-doping feature and pore structure are critical factors for developing nitrogen-doped carbons based catalysts with a high performance toward oxygen reduction reaction (ORR). Herein, a simple one-step CVD of acetylene and acetonitrile vapor method using silanized SBA-15 as a template has been developed to synthesize an ordered porous carbon (OPC) with dual nitrogen-doped interfaces. The optimized sample as prepared with the CVD of 4 h at 750 ℃ contains two types of ordered mesopores that one type is the ordered cylindrical pores inheriting from the pores of SBA-15 and has a pore width of 4.0~5.0 nm, the other type is the ordered quasi-hexagonal pores with a width of 3.0~4.0 nm produced by etching the pore walls of SBA-15. These two types of pores whose pore walls are built by the nitrogen doped carbon layers resulted by the CVD and thus it actually makes the dual nitrogen-doped interfaced OPC (DN-OPC). Meanwhile, DN-OPC contains a few of micropores and a large SSA of 1430 m2/g. This dual-ordered pores and dual nitrogen-doped interfaces cannot only facilitate mass transport but also utilize the active sites of DN-OPC for ORR. Therefore, as metal-free ORR catalyst, DN-OPC exhibits a good activity close to commercial Pt/C catalyst, and an excellent durability and methanol tolerance.
Metal-free direct C(sp3)—H functionalization of 2-alkylthiobenzoic acid to access 1, 3-benzooxathiin-4-one
Ke Yang , Yi Li , Mengjie Song , Shengfei Dai , Zheng-Yi Li , Xiaoqiang Sun
2021, 32(1): 146-149  doi: 10.1016/j.cclet.2020.11.036
[Abstract](227) [FullText HTML] [PDF 923KB](2)
Metal-free direct α-C(sp3)—H intramolecular cyclization of 2-alkylthiobenzoic acid in the presence of Selectfluor is described. This novel strategy provides a facile and efficient method to access important 1, 3-benzooxathiin-4-one derivatives with good functional groups tolerance and yields.
Synthesis of highly ordered AgNPs-coated silica photonic crystal beads for sensitive and reproducible 3D SERS substrates
Juan Li , Wanling Li , Yan Rao , Feng Shi , Suhua Yu , Huizhen Yang , Lingfeng Min , Zhanjun Yang
2021, 32(1): 150-153  doi: 10.1016/j.cclet.2020.10.043
[Abstract](205) [FullText HTML] [PDF 951KB](1)
3D highly ordered silver nanoparticles (AgNPs) coated silica photonic crystal beads (Ag/SPCBs) were prepared and exploited as a novel surface enhanced Raman scattering (SERS) substrate. The monodisperse and size-controlled SPCBs were prepared via self-assembly of silica nanoparticles process using a simple microfluidic device. Then the Ag/SPCBs were easily obtained by in situ growth of AgNPs onto the NH2-modified SPCBs. Field emitting scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDX) were used to characterize the Ag/SPCBs. The effect of silica nanoparticle size and AgNO3 concentration on the SERS performance of the resultant Ag/SPCBs substrate were discussed in detail. The results indicate that the Ag/SPCBs have highest SERS signals when silica nanoparticle size is 250 nm and AgNO3 concentration is 0.8 mg/mL. Using malachite green (MG) as model analyte, the Ag/SPCBs substrate displayed a high sensitivity and a wide linear range for MG. The well-designed Ag/SPCBs show high uniformity and excellent reproducibility, and can be used as an effective SERS substrate for sensitive assay application.
Needle-like cobalt phosphide arrays grown on carbon fiber cloth as a binder-free electrode with enhanced lithium storage performance
Ze Zhang , Peipei Zhu , Chao Li , Ji Yu , Jianxin Cai , Zhenyu Yang
2021, 32(1): 154-157  doi: 10.1016/j.cclet.2020.09.051
[Abstract](246) [FullText HTML] [PDF 916KB](1)
Cobalt phosphide (CoP) is a promising anode candidate for lithium-ion batteries (LIBs) due to its high specific capacity and low working potential. However, the poor cycling stability and rate performance, caused by low electrical conductivity and huge volume variation, impede the further practical application of CoP anode materials. Herein, we report an integrated binder-free electrode featuring needle-like CoP arrays grown on carbon fiber cloth (CC) for efficient lithium storage. The as-prepared CoP/CC electrode integrates the advantages of 1D needle-like CoP arrays for efficient electrolyte wettability and fast charge transportation, and 3D CC substrate for superior mechanical stability, flexibility and high conductivity. As a result, the CoP/CC electrode delivers an initial specific capacity of 1283 mAh/g and initial Coulombic effeciencies of 85.4%, which are much higher than that of conventional CoP electrode. Notably, the CoP/CC electrode shows outstanding cycling performance up to 400 cycles at 0.5 A/cm2 and excellent rate performance with a discharge capacity of 549 mAh/g even at 5 A/cm2. This work demonstrates the great potential of integrated CoP/CC hybrid as efficient bind-free and freestanding electrode for LIBs and future flexible electronic devices.
Substituent-regulated highly X-ray sensitive Os(Ⅵ) nitrido complex for low-toxicity radiotherapy
Mingkai Chen , Xiaoting Huang , Jie Lai , Li Ma , Tianfeng Chen
2021, 32(1): 158-161  doi: 10.1016/j.cclet.2020.11.050
[Abstract](267) [FullText HTML] [PDF 882KB](1)
A high efficiency and low toxicity radiosensitizer, OsN(PhenOH)Cl3, was designed and synthesized through substituent regulation. To the best of our knowledge, this is the first osmium-based coordination complex radiosensitizer. The experimental results shown that this radiosensitizer induced G2/M cell cycle arrest mainly through induction of intracellular ROS overproduction.
ROS-responsive cyclodextrin nanoplatform for combined photodynamic therapy and chemotherapy of cancer
Die Jia , Xianbin Ma , Yi Lu , Xinyi Li , Shengxin Hou , Yuan Gao , Peng Xue , Yuejun Kang , Zhigang Xu
2021, 32(1): 162-167  doi: 10.1016/j.cclet.2020.11.052
[Abstract](243) [FullText HTML] [PDF 1034KB](7)
Cyclodextrin (CD) has special spatial structure and well biological safety, so it has been widely used for constructing CD-based nanoplatforms. Through functionalization, cyclodextrin can form various stimulus-response nanoplatforms, such as pH, temperature, redox, light and magnetic fields. In this study, we designed a highly sensitive reactive oxygen species (ROS)-responsive polymer PCP which encapsulated doxorubicin (DOX) and purpurin 18 (P18) to achieve the synergy of photodynamic and chemotherapy. The high content of reactive oxygen species(ROS) in the tumor microenvironment(TME) triggers the cleavage of the borate bond of MPEG-CD-PHB(PCP), thereby promoting the release of drugs.When irradiated with near-infrared laser, the photosensitizer P18 released by polymer micelles can produce reactive oxygen species to promote cell apoptosis. Compared with monotherapy, a series of experiments confirmed that our micelles had enhanced anti-cancer activity. This work was beneficial to the design of ROS-responsive materials and provides an effective strategy for the application of collaborative anti-tumor therapy.
Pillar[5]arene-functionalized nanochannel platform for detecting chiral drugs
Sheng Yu , Yaqi Wang , Sobhan Chatterjee , Feng Liang , Fei Zhu , Haibing Li
2021, 32(1): 179-183  doi: 10.1016/j.cclet.2020.11.055
[Abstract](202) [FullText HTML] [PDF 841KB](1)
Chirality is a fascinating and essential feature of life and highly associated with many significant pharmaceutical, chemical, and biological processes. The construction of chiral recognition platform is a hot research topic and challenging assignment. Herein, we report an electrochemical method by differential pulse voltammetry (DPV) for the enantioselective recognition of chiral drug propranolol (R/S-PPL) through a nanochannel platform based on the N-acetyl-L-cysteine functionalized Pillar[5]arenes derivative NALC-P5 and the porous polycarbonate membrane. The chiral discrimination depends on the difference in the supramolecular host-guest interaction between the chiral NALC-P5 and the R/S-PPL. The transmission rate of the R/S-PPL can be regulated in the nanochannel and we can achieve the selective transport of the chiral drugs. This simple electrochemical technique has potential applications as a general platform for the recognition of chiral molecules.
Phenylenediamine-formaldehyde chemistry derived N-doped hollow carbon spheres for high-energy-density supercapacitors
Ming Xu , Yuheng Liu , Qiang Yu , Shihao Feng , Liang Zhou , Liqiang Mai
2021, 32(1): 184-189  doi: 10.1016/j.cclet.2020.11.004
[Abstract](242) [FullText HTML] [PDF 1014KB](2)
Porous carbon spheres represent an ideal family of electrode materials for supercapacitors because of the high surface area, ideal conductivity, negligible aggregation, and ability to achieve space efficient packing. However, the development of new synthetic methods towards porous carbon spheres still remains a great challenge. Herein, N-doped hollow carbon spheres with an ultrahigh surface area of 2044 m2/g have been designed based on the phenylenediamine-formaldehyde chemistry. When applied in symmetric supercapacitors with ionic electrolyte (EMIBF4), the obtained N-doped hollow carbon spheres demonstrate a high capacitance of 234 F/g, affording an ultrahigh energy density of 114.8 Wh/kg. Excellent cycling stability has also been achieved. The impressive capacitive performances make the phenylenediamine-formaldehyde resin derived N-doped carbon a promising candidate electrode material for supercapacitors.
Chemical proteomics reveals ligustilide targets SMAD3, inhibiting collagen synthesis in aortic endothelial cells
Wei Lei , Fukui Shen , Nianwei Chang , Lin Niu , Yuanyuan Hou , Boli Zhang , Min Jiang , Gang Bai
2021, 32(1): 190-193  doi: 10.1016/j.cclet.2020.10.049
[Abstract](183) [FullText HTML] [PDF 881KB](2)
Atherosclerosis is a persistent inflammatory state, while vascular endothelial fibrosis is one of the primary causes of atherosclerosis development. Although ligustilide (Lig) was shown to exert obvious antiatherogenic effects in previous studies, its precise mechanism has not been deeply discussed. In this paper, we designed a Lig-derived photoaffinity labelling (PAL) probe to identify potential therapeutic targets of Lig via chemical proteomics approach. Mothers against decapentaplegic homologue 3 (SMAD3), a signal transmitter of transforming growth factor-β (TGF-β) which promotes the development of vascular fibrosis, was identified as a potential target of Lig. Lig suppressed the phosphorylation and nuclear translocation of SMAD3 by blocking the interaction between SMAD3 and TGF-β receptor 1, thereby inhibiting the collagen synthesis process. Hence, developing a novel SMAD3 inhibitor may present a promising therapeutic option for preventing vascular fibrosis.
Synthesis of phosphanaphthalenes and nido-carborane fused six-membered phosphacycles
Guanyu Tao , Feichao Yang , Lujun Zhang , Yang Li , Zheng Duan , François Mathey
2021, 32(1): 194-197  doi: 10.1016/j.cclet.2020.11.018
[Abstract](223) [FullText HTML] [PDF 924KB](3)
A simple method to synthesize luminescent λ5-phosphanaphthalenes and zwitterionic nido-carborane fused six-membered phosphacycles was developed from the reaction of ortho-phosphinobenzoalde-hydes or ortho-phosphinocarboranylaldehydes with an electron-deficient alkyne, respectively. Similar results were obtained with the imino analogues.
Metal-organic framework as a multi-component sensor for detection of Fe3+, ascorbic acid and acid phosphatase
Hao Wang , Xiuli Wang , Rong-Mei Kong , Lian Xia , Fengli Qu
2021, 32(1): 198-202  doi: 10.1016/j.cclet.2020.10.017
[Abstract](258) [FullText HTML] [PDF 781KB](4)
In this research, a hydroxyl group functionalized metal-organic framework (MOF), UiO-66-(OH)2, was synthesized as a "on-off-on" fluorescent switching nanoprobe for highly sensitive and selective detection of Fe3+, ascorbic acid (AA) and acid phosphatase (ACP). UiO-66-(OH)2 emits yellow-green light under ultraviolet light, when Fe3+ was added, Fe3+ was chelated with hydroxyl group, the electrons in the excited state S1 of the MOF transferred to the half-filled 3d orbits of Fe3+, resulting in fluorescence quenching because of the nonradiative electron/hole recombination annihilation. AA could reduce Fe3+ to Fe2+, which can destroy the electron transfer between UiO-66-(OH)2 and Fe3+ after AA adding, resulted in nonoccurrence of the nonradiative electron transfer, leading to the recovery of UiO-66-(OH)2 fluorescence intensity. The probe can also be used to detect ACP based on the enzymolysis of 2-phospho-L-ascorbic acid (AAP) to produce AA. Benefitting from the hydroxyl group and the characteristics of UiO-66, including the high porosity and large surface area, the developed UiO-66-(OH)2 showed extensive advantages as a fluorescent probe for detection of multi-component, such as high sensitivity and selectivity, colorimetric detection, fast response kinetics and easy to operate, economical and secure. This is the first time to use active group functionalized MOFs as a multi-component sensor for these three substances detection.
Ionic/electronic conductivity regulation of n-type polyoxadiazole lithium sulfonate conductive polymer binders for high-performance silicon microparticle anodes
Yuanyuan Yu , Huihui Gao , Jiadeng Zhu , Dazhe Li , Fengxia Wang , Chunhui Jiang , Tianhaoyue Zhong , Shuheng Liang , Mengjin Jiang
2021, 32(1): 203-209  doi: 10.1016/j.cclet.2020.10.010
[Abstract](228) [FullText HTML] [PDF 1137KB](3)
Low-cost silicon microparticles (SiMP), as a substitute for nanostructured silicon, easily suffer from cracks and fractured during the electrochemical cycle. A novel n-type conductive polymer binder with excellent electronic and ionic conductivities as well as good adhesion, has been successfully designed and applied for high-performance SiMP anodes in lithium-ion batteries to address this problem. Its unique features are attributed to the strong electron-withdrawing oxadiazole ring structure with sulfonate polar groups. The combination of rigid and flexible components in the polymer ensures its good mechanical strength and ductility, which is beneficial to suppress the expansion and contraction of SiMP s during the charge/discharge process. By fine-tuning the monomer ratio, the conjugation and sulfonation degrees of the polymer can be precisely controlled to regulate its ionic and electronic conductivities, which has been systematically analyzed with the help of an electrochemical test method, filling in the gap on the conductivity measurement of the polymer in the doping state. The experimental results indicate that the cell with the developed n-type polymer binder and SiMP (~0.5 μm) anodes achieves much better cycling performance than traditional non-conductive binders. It has been considered that the initial capacity of the SiMP anode is controlled by the synergetic effect of ionic and electronic conductivity of the binder, and the capacity retention mainly depends on its electronic conductivity when the ionic conductivity is sufficient. It is worth noting that the fundamental research of this work is also applicable to other battery systems using conductive polymers in order to achieve high energy density, broadening their practical applications.
Si-rhodamine based water-soluble fluorescent probe for bioimaging of Cu+
Xiaoyun Chai , Weiwei Zhu , Qingguo Meng , Ting Wang
2021, 32(1): 210-213  doi: 10.1016/j.cclet.2020.11.032
[Abstract](162) [FullText HTML] [PDF 775KB](3)
A Si-substituted rhodamine based water-soluble fluorescent probe bearing a tetrathia-azacrown was designed for fluorescence imaging of Cu+ with substantial affinity and selectivity. In physiological condition, the developed probe with outstanding water-solubility exhibits ultrahigh sensitivity to Cu+, ensuring the reliable fluorescence imaging in vivo.
Hybrid vesicles of pillar[5]arene/silica: Host-guest complexation and application in pH-triggered release
Chenghao Hou , Lijing Liu , Siyang Meng , Yue Wu , Meiran Xie , Yongkui Shan , Pingang He , Pengfei Sun , Xiaojuan Liao
2021, 32(1): 214-217  doi: 10.1016/j.cclet.2020.11.030
[Abstract](218) [FullText HTML] [PDF 819KB](1)
Integrating silica with organic nanoparticles can generate unique properties. Here pillar[5]arene/silica hybrid vesicles were constructed based on the amphiphilic and rigid properties of pillararenes, as well as the catalytic hydrolysis of tetraethoxysilane. Such vesicles exhibited the high strength of silica and unique molecular recognition of pillararenes, both of which could tune the pH-triggered release behavior. Furthermore, a rhodamine B derivative with hexyl group (RhB-C6) was synthesized, which can form a complex with the pillar[5]arene. Based on the host-guest interaction and high strength of silica, the hybrid vesicles could load more RhB-C6 and the rhodamine B was released more slowly compared with the organic vesicles.
Pressure controllable aptamers picking strategy by targets competition
Ge Yang , Chao Zhu , Liping Zhao , Linsen Li , Yuanyu Huang , Yukui Zhang , Feng Qu
2021, 32(1): 218-220  doi: 10.1016/j.cclet.2020.10.018
[Abstract](185) [FullText HTML] [PDF 710KB](1)
Selection of aptamers with high affinity and good specificity requires multiple rounds of alternating steps of separation and PCR amplification. Herein, we proposed a novel high-efficiency aptamers picking strategy: One-round pressure controllable selection (OPCS). OPCS integrates four types of screening superiority, high-efficiency separation, one-round selection and PCR amplification, synchronous negative selection and targets competition. The controllable screening pressure can be achieved through two approaches, balanced competition by the regulation of protein concentration, and dominant competition by introducing a predatory protein with high concentration. In OPCS process, two proteins were co-incubated with one ssDNA library, and each protein bound its favorable sequences specifically and formed protein-ssDNA complex respectively. Meanwhile, one protein could supply/suffer the picking pressure of affinity and specificity to/from another, which eliminated weakly bound or unbound sequences for each other. Two complexes could be separated and collected conveniently, and aptamers for two proteins obtained synchronously with high affinity and good specificity. This strategy not only provides a more effective way for aptamers selection, but shows great potential in other ligands or drugs selection.
Ternary solvent-processed efficient organic solar cells based on a new A-DA'D-A acceptor derivative employing the 3rd-position branching side chains on pyrroles
Yu Chen , Honggang Chen , Huilan Guan , Wei Liu , Zhe Li , Hui Liu , Yongfang Li , Yingping Zou
2021, 32(1): 229-233  doi: 10.1016/j.cclet.2020.10.042
[Abstract](257) [FullText HTML] [PDF 774KB](3)
Recent advances in non-fullerene acceptors (NFAs), typically Y6, have driven power conversion efficiency (PCE) of single-junction organic solar cells (OSCs) over 16%. Meanwhile, it becomes essential to know how to adopt simple strategies to further improve device performance. In this work, a new A-DA'D-A acceptor derivative, Y19-N3 employing 3-ethylheptyl branched at the 3rd-position instead of 2-ethylhexyl on the pyrroles of Y19 is reported. The selection of an appropriate solvent in casting device is implemented to maximize the photovoltaic performance. PBDB-T: Y19-N3-based OSCs treated with a ternary solvent of CF/CB (1:3, v/v) and 0.8% DIO exhibit the optimal PCE of 13.77% here, with the significantly improved Voc (0.78 V) and FF (0.72) as well as the high Jsc (24.46 mA/cm2). Further characterizations indicate that this ternary solvent-treated PBDB-T/Y19-N3 film exhibits the more appropriate morphological features with the highly efficient charge generation and collection as well as the more balanced electron and hole mobilities. This work combines molecular design and device engineering to improve the photovoltaic properties, which is important to the development of OSCs.
L-Arginine/nanofish bone nanocomplex enhances bone regeneration via antioxidant activities and osteoimmunomodulatory properties
Liping Huang , Jianhua Zhang , Xianhu Liu , Tianbao Zhao , Zhipeng Gu , Yiwen Li
2021, 32(1): 234-238  doi: 10.1016/j.cclet.2020.11.046
[Abstract](107) [FullText HTML] [PDF 1119KB](1)
In this study, a promising strategy has been developed to promote bone regeneration by combining antioxidant activities and osteoimmunomodulatory properties. Herein, an L-arginine/nanofish bone (Arg/NFB) nanocomplex has been prepared and evaluated in vitro and in vivo. The Arg/NFB nanocomplex possesses good antioxidant activities and could modulate the polarization of non-activated macrophage into different types and induce the secretion of pre-inflammatory, anti-inflammatory, osteogenic as well as angiogenic cytokines. Additionally, the regulated immune microenvironment can enhance the osteogenic differentiation of mouse embryo osteoblast precursor cells (MC3T3-E1) and angiogenic capacity of human umbilical vein endothelial cells (HUVECs), leading to the improved formation of mineralized nodules, alkaline phosphatase activity and angiogenic effects. In vivo results with cranial defect models reveal that the treatment of Arg/NFB nanocomplex exhibited significant improvement of new bone formation and angiogenesis. All the results demonstrate Arg/NFB nanocomplex with antioxidant activities and osteoimmunomodulatory properties could be a new idea for developing the next generation of bone regeneration biomaterials.
Synthesis of planar chiral isoquinolinone-fused ferrocenes through palladium-catalyzed C-H functionalization reaction
Lantao Liu , Huihui Liu , Zhenzhen Zuo , An-An Zhang , Zhongyi Li , Tuanjie Meng , Wei Wu , Yuanzhao Hua , Guoliang Mao
2021, 32(1): 239-242  doi: 10.1016/j.cclet.2020.10.034
[Abstract](224) [FullText HTML] [PDF 911KB](1)
(S, S)-Me-BI-DIME/Pd(0)-catalyzed ennantioselective C–H functionalization of N-ferrocenyl o-bromo-benzanilides has been realized, affording isoquinolinone-fused ferrocenes with up to 97% ee. The products can be transformed into planar chiral ferrocenyl monophosphines, which demonstrate their preliminary application.
Visible-light-induced three-component reaction of quinoxalin-2(1H)-ones, alkenes and CF3SO2Na leading to 3-trifluoroalkylated quinoxalin-2(1H)-ones
Na Meng , Yufen Lv , Qishun Liu , Ruisheng Liu , Xiaohui Zhao , Wei Wei
2021, 32(1): 258-262  doi: 10.1016/j.cclet.2020.11.034
[Abstract](230) [FullText HTML] [PDF 886KB](3)
A facile and metal-free visible-light-enabled three-component reaction of quinoxalin-2(1H)-ones, alkenes and CF3SO2Na has been developed under air at room temperature. This photocatalytic tandem reaction using 4CzIPN as the photocatalyst and air as the green oxidant, provides a mild and environmentally friendly approach to access a series of 3-trifluoroalkylated quinoxalin-2(1H)-ones.
Noncentrosymmetric K2Mn3(SO4)3F2·4H2O and Rb2Mn3(SO4)3F2·2H2O with pseudo-KTP structures
Yang Zhou , Yanqiang Li , Qingran Ding , Youchao Liu , Yangxin Chen , Xitao Liu , Xiaoying Huang , Lina Li , Sangen Zhao , Junhua Luo
2021, 32(1): 263-265  doi: 10.1016/j.cclet.2020.11.014
[Abstract](213) [FullText HTML] [PDF 808KB](2)
Two fluoride sulfates, K2Mn3(SO4)3F2·4H2O (I) and Rb2Mn3(SO4)3F2·2H2O (Π) are obtained by water solution method. Single-crystal X-ray diffraction analysis indicated that they crystallize in space groups of Cmc21. Their structures feature a pseudo-KTP structure consisting of interconnecting [Mn3(SO4)3F2(H2O)2] layers, which are further packing along the a axis with alkali metal cations balancing the charges. The structure relationships between the two compounds are discussed. Second-harmonic generation measurements manifest that I and Π have similar second-harmonic generation responses of about 0.2 and 0.25 times that of KH2PO4.
Ultra-small nanodots coated with oligopeptides providing highly negative charges to enhance osteogenic differentiation of hBMSCs better than osteogenic induction medium
Yueqi Zhao , Lin Meng , Kai Zhang , Yuanqing Sun , Yue Zhao , Zhe Yang , Yangliu Lin , Xinrui Liu , Hongchen Sun , Bai Yang , Quan Lin
2021, 32(1): 266-270  doi: 10.1016/j.cclet.2020.10.031
[Abstract](203) [FullText HTML] [PDF 821KB](1)
For bone regenerative engineering, it is a promising method to form skeletal tissues differentiating from human bone morrow mesenchyme stem cells (hBMSCs). However, it is still a critical challenge to efficiently control ostogenesis and clearly reveal the influence factor. To this end, the fluorescent gold nanodots (Au NDs) with highly negative charges as osteogenic induction reagent are successfully synthesized, which display better than commercial osteogenic induction medium through the investigations of ALP activity (2.5 folds) and cytoskeleton staining (1.5 folds). Two kinds of oligopeptides with different bio-structures (cysteine, Cys and glutathione, GSH) are selected for providing surficial charges on Au NDs. It is revealed that Au-Cys with more negative charges (-51 mV) play better role than Au-GSH (-19 mV) in osteogenic differentiation, when both of them have same size (~2 nm), sphere shape and show similar cell uptake amount. To explore deeply, osteogenesis related signaling pathways are monitored, revealing that the enhancement of osteogenic differentiation was through autophagy signaling pathway triggered by Au-Cys. And the promotion of highly negative charges in osteogenic differentiation was further proved via sliver nanodots (Ag NDs, Ag-Cys and Ag-GSH) and carbon nanodots (CDs, Cys-CDs and GSH-CDs). This work indicates part of insights during hBMSCs differentiation and provides a novel strategy in osteogenic differentiation process.
Polyoxygenated anti-inflammatory biscembranoids from the soft coral Sarcophyton tortuosum and their stereochemistry
Yufen Li , Songwei Li , Cristina Cuadrado , Chenglong Gao , Qihao Wu , Xiaolu Li , Tao Pang , Antonio Hernandez Daranas , Yuewei Guo , Xuwen Li
2021, 32(1): 271-276  doi: 10.1016/j.cclet.2020.11.037
[Abstract](198) [FullText HTML] [PDF 964KB](2)
Five novel biscembranoids, ximaolides H–L (1–5), along with four known related compounds (6–9) were isolated from the Hainan soft coral Sarcophyton tortuosum. The structures of the new compounds were determined by extensive spectroscopic analysis, quantum chemical calculations, and/or by comparing their CD spectra with those of the known compounds. Compounds 1 and 2 are the first examples of biscembranoids bearing a 1,35-bridged lactone moiety, 4 is the first biscembranoid comprising an uncommon oxetane ring, and 5 represents the first 36-peroxyl biscembranoid. Ximaolides I (2), K (4) and F (9) exhibited interesting anti-inflammatory activity by the inhibition of LPS-induced TNF-α protein release in RAW264.7 macrophages.
Why the hydrothermal fluorinated method can improve photocatalytic activity of carbon nitride
Gang Zhao , Yupeng Xing , Shuhua Hao , Xijin Xu , Wenxuan Ma , Jinghua Guo
2021, 32(1): 277-281  doi: 10.1016/j.cclet.2020.11.033
[Abstract](213) [FullText HTML] [PDF 780KB](2)
Carbon nitride (CN) photocatalysts have attracted much attention due to their excellent photocatalytic properties. And hydrothermal fluorination is a common method to improve the photocatalytic effect of CN photocatalyst. Here, the influence of the band gap was first revealed of fluorination and hydroxylation of CN photocatalyst based on the first theoretical principle. Here, the effect of fluorination and hydroxylation on the CN band gap was discussed for the first time using the first theoretical principle. With F atoms and OH doping, the band gap of CN was significantly improved, conduction band and valence band moved up. Then, F—CN photocatalyst with F atoms and OH was successfully synthesized by a hydrothermal fluorinated method. Next, the reasons why F—CN photocatalyst was more effective than that of traditional CN photocatalyst were fully discussed. From the photocatalytic effect of photocatalyst (12, 593.2 μmol g-1 h-1 to the morphology (super-small nanosheets), structure (homojunctions), composition (metal-free), specific surface area (54.1 m2/g), visible light absorption response (AQE is 10.9% at 420 nm) and photo-induced carrier life (14.13 ns). Therefore, this work has a great guiding effect on the development of CN photocatalyst.
Se-decorated SnO2/rGO composite spheres and their sodium storage performances
Peng Zhang , Bin Cao , Razium A. Soomro , Ning Sun , Bin Xu
2021, 32(1): 282-285  doi: 10.1016/j.cclet.2020.10.006
[Abstract](208) [FullText HTML] [PDF 959KB](2)
SnO2 is considered a promising anode material for sodium-ion batteries due to its high theoretical capacity and low cost. However, the poor electrical conductivity and dramatic volume variation during charge/discharge cycling is a major limitation in its practical applicability. Here we propose a simple one-pot spray pyrolysis process to construct unique pomegranate-like SnO2/rGO/Se spheres. The ideal structural configuration of these architectures was effective in alleviating the large volume variation of SnO2, besides facilitating rapid electron transfer, allowing the devised anode to exhibit superior sodium storage performances in terms of capacity (506.7 mAh/g at 30 mA/g), cycle performance (397 mAh/g after 100 cycles at 50 mA/g) and rate capability (188.9 mAh/g at an ultrahigh current density of 10 A/g). The experimental evidence confirms the practical workability of p-SnO2/rGO/Se spheres in SIBs.
Understanding the dehydrogenation mechanism over iron nanoparticles catalysts based on density functional theory
Wenjuan Yang , Yating Zhu , Junjun Li , Zheng Chen , Farhat Nosheen , Qitao Zhang , Zhicheng Zhang
2021, 32(1): 286-290  doi: 10.1016/j.cclet.2020.10.040
[Abstract](222) [FullText HTML] [PDF 861KB](1)
The conversion of chemical feedstock materials into high value-added products accompanied with dehydrogenation is of great value in the chemical industry. However, the catalytic dehydrogenation reaction is inhibited by a limited number of expensive noble metal catalysts and lacks understanding of dehydrogenation mechanism. Here, we report the use of heterogeneous non-noble metal iron nanoparticles (NPs) incorporated mesoporous nitrogen-doped carbon to investigate the dehydrogenation mechanism based on experiment observation and density functional theory (DFT) method. Fe NPs catalyst displays excellent performance in the dehydrogenation of 1, 2, 3, 4-tetrahydroquinoline (THQ) with 100% selectivity and 100% conversion for 10-12 h at room temperature. The calculated adsorption energy implies that THQ prefers to adsorb on Fe NPs as compared with absence of Fe NPs. What is more, the energy barrier of transition state is relatively low, illustrating the dehydrogenation is feasible. This work provides an atomic scale mechanism guidance for the catalytic dehydrogenation reaction and points out the direction for the design of new catalysts.
Pyrene-tiaraed pillar[5]arene: Strong intramolecular excimer emission applicable for photo-writing
Chao Peng , Wenting Liang , Jiecheng Ji , Chunying Fan , Kuppusamy Kanagaraj , Wanhua Wu , Guo Cheng , Dan Su , Zhihui Zhong , Cheng Yang
2021, 32(1): 345-348  doi: 10.1016/j.cclet.2020.03.079
[Abstract](205) [FullText HTML] [PDF 866KB](7)
A pyrene-tiaraed pillar[5]arene derivative was synthesized, which showed a concentration-independent intensive excimer emission. Photolysis of the pyrene-tiaraed pillar[5]arene led to a switch from excimer to monomer emission, applicable to photo-writing.
CO2 and photo-controlled reversible conversion of supramolecular assemblies based on water soluble pillar[5]arene and coumarin-containing guest
Yufeng Cao , Yanmei Chen , Zhecheng Zhang , Jin Wang , Xiaolei Yuan , Qin Zhao , Yue Ding , Yong Yao
2021, 32(1): 349-352  doi: 10.1016/j.cclet.2020.03.058
[Abstract](191) [FullText HTML] [PDF 776KB](3)
In this communication, a new supramolecualr amphiphile was successfully constructed based on water soluble pillar[5]arene and a unique guest which contain a CO2 responsive tertiary amine unit and a UV responsive coumarin group. When guest molecule 1 dispersed in water, it self-assembled into sheet-like structures. Upon bubbling CO2, 1 transformed into 1H due to the tertiary amine unit was protonated, accompany the nano-sheets transformed into vesicles. Further irradiation of 1H with 365 nm light for 3 h, the coumarin group reacted with each other to form bola-type amphiphie 2H. In this case, vesicles collapsed and re-assembled into nano-tubes. However, when addition of WP5 into the solution of 1H, the vesicles transformed into micelles, this is due to the formation of supramolecular amphiphile WP5&1H. Upon irradiation of WP5&1H with 365 nm light for 3 h, nano-ribbons observed instead of micelles in the solution. Notably, nanotubes from 2H could also transform into nano-ribbons after adding WP5. The self-assembly process and the resultant assemblies were characterized by TEM, SEM, DLS, SAXS and NMR technologies. Due to both CO2 and light are pgreenq for living organisms, we anticipated our system can offer the possibilities in pon demandq drug absorption and release.
Native conjugation between proteins and [60]fullerene derivatives using SpyTag as a reactive handle
Guangzhong Yin , Jingjing Wei , Yu Shao , Wen-Hao Wu , Lianjie Xu , Wen-Bin Zhang
2021, 32(1): 353-356  doi: 10.1016/j.cclet.2020.04.034
[Abstract](230) [FullText HTML] [PDF 815KB](1)
Herein, we report the facile conjugation between proteins and water-soluble [60]fullerene derivatives (DC60) under native conditions using SpyTag as a reactive handle. Water-soluble [60]fullerene derivatives were first prepared via sequential Bingel-Hirsch reaction and pclickedq with SpyTag to give DC60-SpyTag for native conjugation with proteins by the highly efficient SpyTag-SpyCatcher chemistry. The bioconjugation was confirmed by MALDI-TOF MS spectra and SDS-PAGE analysis. The TEM and UV-vis spectroscopic study further revealed that the DC60 could alter the optical performance and induce aggregation of the target proteins. It thus provides a general and robust method for modifying proteins with C60 derivatives and could potentially be adapted for native conjugation between proteins and other nonbiological motifs as well.
Metal-organic supramolecular nanoarchitectures by Ru(Ⅱ) bis-(terpyridine)-bridged pillar[5]arene dimers with triphenylamine
Tianwei Cui , Guoxing Liu , Wenjing Zhang , Xinju Zhu , Juhua Leng , Xin-Qi Hao , Pu Mao , Mao-Ping Song
2021, 32(1): 357-361  doi: 10.1016/j.cclet.2020.02.024
[Abstract](248) [FullText HTML] [PDF 977KB](1)
A metal-organic photoinduced electron transfer (PET) supramolecular nanoarchitecture comprised of Ru(Ⅱ) bis(terpyridine)-modified pillar[5]arene (electron acceptor) and triazole triphenylamine amyl cyanide (electron donor) has been designed and constructed. Through the comparison of diverse solvents and acceptors, the two conditions, i.e., modification of pillar[5]arene to donor and weak polar solvent are benefit for the occurrence of "efficient PET" because of shorter D-A distance in the presence of pillar[5]arene. Crucially, the fluorescence and PET process of the supramolecular assembly could be further modulated by solvent conversion and another competitive guest. The study provides a supramolecular method to design and construct tunable PET systems and PET-based smart materials.
Cucurbit[6]uril-based supramolecular frameworks assembled via the outer surface interaction of cucurbit[n]urils
Chao Liu , Ruihan Gao , Yunqian Zhang , Qianjiang Zhu , Zhu Tao
2021, 32(1): 362-366  doi: 10.1016/j.cclet.2020.05.014
[Abstract](206) [FullText HTML] [PDF 1018KB](1)
Curcurbit[n]uril (Q[n])-based supramolecular frameworks (QSFs) constructed from the outer surface interaction of Q[n]s (OSIQ) have the characteristic of simplicity, diversity and modulability. Their simplicity is reflected in their simple composition and preparation methods used for QSFs. The diversity of supramolecular organic frameworks (SOFs) is reflected in the synthesis methods and structural characteristics of the as-obtained QSFs, as well as the variety of structural directing agents and basic building blocks used to prepare QSFs. The modulability is reflected by the controllable channel size in the QSFs, which can be adjusted using different sizes of Q[n]s. In this work, the first reported cucurbituril Q[6] was selected as the basic building block and three Q[6]-based supramolecular frameworks were obtained from aqueous HCl solutions in the presence of [CdCl4]2- respectively. The OSIQs are the main driving forces for the formation of these frameworks. This study shows the diversity of the QSFs.
A supramolecular fluorescent probe based on cucurbit[10]uril for sensing the pesticide dodine
Yang Luo , Wei Zhang , Ming Liu , Jie Zhao , Ying Fan , Bing Bian , Zhu Tao , Xin Xiao
2021, 32(1): 367-370  doi: 10.1016/j.cclet.2020.02.023
[Abstract](289) [FullText HTML] [PDF 908KB](5)
We report herein a new fluorescent probe for the selective recognition and determination of dodine among 20 different pesticides. This fluorescent probe was assembled through host-guest complexation between cucurbit[10]uril (Q[10]) and aminopropyl-1-pyrenebutanamide (PBA) and is designated as PBA@Q[10]. Addition of dodine to PBA@Q[10] results in a dramatic enhancement of fluorescence intensity at 390 nm, accompanied by fluorescence quenching at 488 nm. On this basis, the detection limit is 6.78×10-7 mol/L. The response mechanism is a competitive interaction: dodine occupies the cavity of Q[10] and forces PBA to leave.
Guest induced morphology transitions of star shaped pillar[5]arene trimer via endo host-guest and "exo-wall" electron-transfer interactions
Wajahat Ali , Weitao Gong , Mehdi Hassan , Weidong Qu , Lu Liu , Guiling Ning
2021, 32(1): 371-374  doi: 10.1016/j.cclet.2020.03.044
[Abstract](187) [FullText HTML] [PDF 1039KB](1)
Star shape bridged pillar[5]arene trimer (C3-PLT) based on benzene-1,3,5-tricarboxamide (BTAs) was successfully synthesized, which exhibited outstanding guest responsive morphology transition properties. The morphology tuning studies was efficiently achieved with the addition of competitive guest molecules G1 and G2 by various self-assembly mechanisms. C3-PLT itself displays nanofiber morphology through H-type π-π stacking, and this nanofiber morphology can be completely transformed into spherical vesicles by host-guest interaction G1, while upon addition of G2 into C3-PLT by means of "exo-wall" electron-transfer interactions, sheet superstructures can be observed. SEM, 1H NMR, DOSY, fluorescence spectroscopy, and viscosity have verified the formation of supramolecular polymers and morphological transitions between C3-PLT with both guests.
Cucurbit[n]uril-calix[n]arene-based supramolecular frameworks assembled using the outer surface interactions of cucurbit[n]urils
Ming Liu , Yang Zhou , Lixia Chen , Bing Bian , Xin Xiao , Zhu Tao
2021, 32(1): 375-379  doi: 10.1016/j.cclet.2020.03.042
[Abstract](230) [FullText HTML] [PDF 1108KB](1)
Based on the crystal structures of two cucurbit[6]uril/calix[n]arene-based supramolecular frameworks reported by Long and co-workers, we further investigated the interactions of cucurbit[6]uril with 4-sulfocalix[4]arene and 4-sulfocalix[6]arene using 1H NMR spectroscopy and isothermal titration calorimetry (ITC), respectively. Moreover, solid fluorescent materials were prepared via the adsorption of fluorescent dyes by these porous supramolecular frameworks, which exhibit a selective response to certain volatile organic compounds.
Scalable Cu(Ⅱ)-mediated intramolecular dehydrogenative phenol-phenol coupling: Concise synthesis of enantiopure axially chiral homo- and hetero-diphenols
Yuefei Gu , Tianyang Wang , Ming Gao , Zhu-Jun Yao
2021, 32(1): 380-384  doi: 10.1016/j.cclet.2020.02.015
[Abstract](210) [FullText HTML] [PDF 1019KB](3)
An intramolecular dehydrogenative homo- and hetero-coupling of phenols has been successfully developed for quick preparation of enantiopure axial diphenols under mild Cu(Ⅱ)-mediated conditions, using ((4S, 5S)-2,2-dimethyl-1,3-dioxolane-4,5-diyl)dimethanol as the chiral auxiliary. The commercially available (R)-α-methylbenzylamine was identified as the best amine ligand for Cu(Ⅱ) in the reactions. A variety of homo/hetero bis-dihydroxylbenzoate substrates were examined, affording the corresponding axially chiral diphenols with satisfactory to excellent diastereomeric ratios, and a representative scalable preparation was also attempted. A formal synthesis of natural product (+)-deoxyschizandrin has been achieved in this work using one axially chiral diphenol as the synthetic intermediate.
Rh(Ⅰ)-catalyzed regio- and enantioselective allylic alkylation of Meldrum's acid
Min Liu , Haiying Zhao , Changkun Li
2021, 32(1): 385-388  doi: 10.1016/j.cclet.2020.04.009
[Abstract](262) [FullText HTML] [PDF 902KB](3)
A Rh(Ⅰ)-catalyzed highly regio- and enantioselective allylic alkylation of Meldrum acid with racemic allylic substrates bearing alkyl groups has been developed. The applying of chiral bisoxazopinephosphine ligand is essential for the high yields and selectivities. This method provides a rapid access to various chiral β-alkyl-λ, δ-unsaturated carboxylic acids and their derivatives.
Facile syntheses of 3-trifluoromethylthio substituted thioflavones and benzothiophenes via the radical cyclization
Lu Wang , Huaiyu Wang , Weidong Meng , Xiu-Hua Xu , Yangen Huang
2021, 32(1): 389-392  doi: 10.1016/j.cclet.2020.02.040
[Abstract](242) [FullText HTML] [PDF 885KB](5)
3-CF3S substituted thioflavones and benzothiophenes were achieved via the reactions of AgSCF3 with methylthiolated alkynones and alkynylthioanisoles, respectively, promoted by persulfate. This protocol possesses good functional group tolerance and high yields. Mechanistic studies suggested that a classic two-step radical process was involved, which includes addition of CF3S radical to triple bond and cyclization with SMe moiety.
Access to pyridines via cascade nucleophilic addition reaction of 1,2,3-triazines with activated ketones or acetonitriles
Yuan Zhang , Han Luo , Qixing Lu , Qiaoyu An , You Li , Shanshan Li , Zongyuan Tang , Baosheng Li
2021, 32(1): 393-396  doi: 10.1016/j.cclet.2020.03.075
[Abstract](186) [FullText HTML] [PDF 980KB](3)
We studied the cascade nucleophilic addition reactions of 1,2,3-triazines with activated acetonitriles or ketones, which were used to construct highly substituted pyridines that are not easily accessed by conventional methods. The strategy addressed some structural diversity issues currently facing medicinal chemistry, and the resulting pyridines could be used as convenient precursors for the synthesis of related pharmaceuticals. In particular, our method was applied to the syntheses of the marketed drug etoricoxib and several biologically important molecules in a few steps.
Super rigid tris-spirobifluorenes: Syntheses and properties
Luyao Zhao , Chunbo Duan , Dongxue Ding , Shihui Liu , Debin Xia , Ying Guo , Hui Xu , Martin Baumgarten
2021, 32(1): 397-400  doi: 10.1016/j.cclet.2020.02.001
[Abstract](264) [FullText HTML] [PDF 828KB](1)
In this work, a blue emitter with a 3D rigid structure composed of multiple spirobifluorene (3-Spiro) has been synthesized and characterized. Through a detailed study of the electrochemical and photophysical properties of 3-Spiro, we have evidenced that 3-Spiro can be applied as an active component of organic light-emitting diodes (OLEDs). The device with 5% doping rate of 4CzPNPh exhibits high external quantum efficiency (EQE) of 11%, which proves the potential of 3D rigid structure emitters for OLEDs.
Synthetic studies towards (-)-deserpidine: Total synthesis of the stereoisomer and derivative of (-)-deserpidine
Pingzhou Wu , Qilong Zhou , Xiao-Yu Liu , Fei Xue , Yong Qin
2021, 32(1): 401-404  doi: 10.1016/j.cclet.2020.02.009
[Abstract](303) [FullText HTML] [PDF 944KB](3)
The asymmetric synthesis of 16, 17, 20-epi-deserpidine and a derivative of (-)-deserpidine has been achieved. Key features in the assembly of the pentacyclic framework include a visible-light photocatalytic intra-/inter-/intramolecular radical cascade reaction to construct the tetracyclic ABCD ring system in one-pot and an intramolecularaldol reaction to forge the cyclohexane E ring.
Pd-Catalyzed enantioselective synthesis of 2-methyl-3-methyleneindoline
Chun-Hua Lu , Sima Darvishi , Vahid Khakyzadeh , Changkun Li
2021, 32(1): 405-407  doi: 10.1016/j.cclet.2020.02.056
[Abstract](190) [FullText HTML] [PDF 879KB](2)
A Pd-catalyzed enantioselective synthesis of 2-methyl-3-methyleneindoline in up to 89% yield and 84% ee from racemic vinyl benzoxazinanones has been developed with the help of (R,R)-BenzP* ligand. Mechanism studies support the formation of palladacyclobutane as the key intermediate via C2 attack to π-allyl Pd complex. The β-hydride elimination provides a new reaction pathway for the palladacyclobutane.
A gram-scale laboratory synthesis of Annonaceous acetogenin mimic AA005
Baobao Yu , Zhu-Jun Yao
2021, 32(1): 408-412  doi: 10.1016/j.cclet.2020.06.007
[Abstract](210) [FullText HTML] [PDF 930KB](1)
AA005 (1), a potent anticancer mimicking molecule of natural Annonaceous acetogenin, features a central C2-symmetric triglycol moiety and three stereogenic centers. To support ongoing animal studies, a scalable 10-step synthesis of AA005 (1) has been studied, optimized and accomplished in this work, starting from commercially available economic materials ethylene glycol and (R)-epichlorohydrin. A regio- and stereo-controlled BF3·Et2O-promoted epoxide opening of (R)-epichlorohydrin with ethylene glycol was investigated, optimized and successfully applied to the scalable preparation of the crucial fragment 6a with C2-symmetry. Further successive epoxide openings elaborated both two side chains and the whole skeleton with proper nucleophiles and electrophiles. Comparison and optimization of the reaction sequences finally led to completion of a new multi-gram synthesis of AA005 (1) with satisfactory enantiomeric and diastereomeric purity.
Mn(Ⅲ)-mediated radical reaction of 2-isocyano-6-alkenyl(alkynyl) benzonitriles with arylboronic acids: Synthesis of pyrroloisoquinoline derivatives
Pei Xu , Yi-Ming Zhu , Xin-Yu Liu , Xiao-Zhou Zhou , Shun-Yi Wang , Shun-Jun Ji
2021, 32(1): 413-416  doi: 10.1016/j.cclet.2020.03.023
[Abstract](227) [FullText HTML] [PDF 862KB](1)
A Mn(Ⅲ) mediated radical reaction of new designed multi-functionalized 2-isocyano-6-alkenyl(alkynyl) benzonitriles with arylboronic acids has been developed. This reaction provides a method for the synthesis of pyrroloisoquinoline derivatives through the formation of two C—C bonds and one C—N bond via radical cascade cyclization in one step.
Synthesis of difluoromethylated benzylborons via rhodium(I)-catalyzed fluorine-retainable hydroboration of gem-difluoroalkenes
Yuanhong Cai , Donghang Tan , Qiqi Zhang , Wenxin Lv , Qingjiang Li , Honggen Wang
2021, 32(1): 417-420  doi: 10.1016/j.cclet.2020.03.031
[Abstract](221) [FullText HTML] [PDF 811KB](2)
The synthesis of borylated organofluorines is of great interest due to their potential values as synthons in modular construction of fluorine-containing molecules. Reported herein is a rhodium-catalyzed hydroboration of aryl gem-difluoroalkenes leading to a series of α-difluoromethylated benzylborons. The use of cationic rhodium catalyst and a biphosphine ligand with large bite angle was crucial for reactivity by offering good regioselectivity and diminishing the undesired β-F elimination. Preliminary derivatizations of the products were conducted to showcase the utility of this protocol.
BF3-promoted annulation of azonaphthalenes and ynamides for synthesis of benzo[e]indoles
Changwei Chen , Sunliang Cui
2021, 32(1): 421-424  doi: 10.1016/j.cclet.2020.04.010
[Abstract](239) [FullText HTML] [PDF 828KB](1)
A novel BF3-promoted [3 + 2] annulation of azonaphthalenes and ynamides is described. This protocol provides a modular and efficient entry to functionalized amino benzo[e]indole derivatives smoothly.
Orientation effects on C2(5)-C2'(5') linked bioxazole isomers synthesized via regioselective and sequential C—H arylation
Qiang Guo , Li Tao , Chuanqi Liu , Xiaoyun Zhao , Danyang Wan , Jincheng Zhang , Jianping Ai , Jie Li
2021, 32(1): 425-428  doi: 10.1016/j.cclet.2020.05.010
[Abstract](228) [FullText HTML] [PDF 832KB](2)
Bis(4-fluorophenyl) substituted oxazole(2,5-Oxz) and C2(5)-C2'(5') linked bioxazole isomers(C2-C2'_BOxz, C2-C5'_BOxz and C5-C5'_BOxz) were concisely synthesized via palladium-catalyzed regioselective and sequential C—H arylation in 1–3 reaction steps along with 20%–83% of total yields from oxazole and 4-bromofluorobenzene.The linking orientation plays a key role in the packing geometry and photophysical properties of C2-C2'_BOxz, C2-C5'_BOxz and C5-C5'_BOxz. These bioxazole isomers in solid state showed significant differences in photoluminescence quantum yields (PLQY) (0.33, 0.25 and 0.04, respectively), delayed fluorescence properties and powder X-ray diffraction (PXRD) patterns, suggesting the divergence in intermolecular interactions. The theoretically calculated gradient isosurfaces and complexation energies indicate the existence of intense π-π interactions between molecular layers, which are in good agreement with the variation trend of optical properties.
A practical synthesis of α-bromo/iodo/chloroketones from olefins under visible-light irradiation conditions
Zhihui Wang , Lei Wang , Zhiming Wang , Pinhua Li , Yicheng Zhang
2021, 32(1): 429-432  doi: 10.1016/j.cclet.2020.02.022
[Abstract](242) [FullText HTML] [PDF 882KB](7)
A practical synthesis of α-bromo/iodo/chloroketones from olefins under visible-light irradiation conditions has been developed. In the presence of PhI(OAc)2 as promoter and under ambient conditions, the reactions of styrenes and triiodomethane undergo the transformation smoothly to deliver the corresponding α-iodoketones without additional photocatalyst in good yields under sunlight irradiation. Meanwhile, the reactions of styrenes with tribromomethane and trichloromethane generate the desired α-bromoketones and α-chloroketones in high yields by using Ru(bpy)3Cl2 as a photocatalyst under blue LED (450–455 nm) irradiation.
Cascade reaction involving intramolecular oxygen-migration: Efficient synthesis of 3-allylidene-indolin-2-one compounds under metal-free conditions
Rui-Ying Zhang , Meng-Meng Xu , Hai-Yan Li , Xiao-Ping Xu , Shun-Jun Ji
2021, 32(1): 433-436  doi: 10.1016/j.cclet.2020.03.070
[Abstract](224) [FullText HTML] [PDF 986KB](3)
An efficient synthesis of 3-(diarylallylidene)oxindoles from 3-(1H-indol-3-yl)-1, 1-diarylpropan-1-ol under metal-free conditions is described. NBS serves as a critical medium leading to a facile oxygen-migration in the transformation. The protocol has advantages of high efficiency, simple opreation, mild reaction conditions, good atom-economy, wide substrate scope and good yields of products. A detailed mechanism is proposed after careful investigation.
Palladium-catalyzed concerted [4 + 1] cyclization of prop-2-yn-1-ones and isocyanides
Yingying Shan , Lei Su , Dianpeng Chen , Min Yang , Wenlin Xie , Guanyinsheng Qiu
2021, 32(1): 437-440  doi: 10.1016/j.cclet.2020.04.041
[Abstract](216) [FullText HTML] [PDF 924KB](1)
A palladium-catalyzed [4 + 1] cycloaddition of prop-2-yn-1-ones with double isocyanides is developed herein. The transformation worked well to produce a series of 2-amino-4-cyanofurans with high efficiency and a broad reaction scope. Based on mechanism studies, it is believed that the palladium-catalyzed [4 + 1] imidoylative cycloaddition of prop-2-yn-1-ones was concerted. Treated with aryl amine and H2O, the [4 + 1] cycloaddition of prop-2-yn-1-ones with double isocyanides provided 2-amino-4-amidylpyrroles efficiently.
The role of CuI in the siloxane-mediated Pd-catalyzed cross-coupling reactions of aryl iodides with aryl lithium reagents
Yu Chen , Xiao Zhang , Fang Liu , Gucheng He , Ju Zhang , K.N. Houk , Amos B. Smith Ⅲ , Yong Liang
2021, 32(1): 441-444  doi: 10.1016/j.cclet.2020.05.009
[Abstract](129) [FullText HTML] [PDF 816KB](1)
Experiments indicate that a catalytic amount of CuI plays an important role in the siloxane-mediated Pd-catalyzed cross-coupling reactions with the direct use of organolithium reagents. Addition of organolithium to the siloxane transfer agent generates an organosilicon intermediate. DFT calculations indicate that CuI initially accelerates the Si-Pd(Ⅱ) transmetalation of the organosilicon intermediate by the formation of CuI2-. Subsequently, CuI2- works as a shuttle between the Si-Cu(I) and Cu(I)-Pd(Ⅱ) transmetalation processes.
One-pot synthesis of dual-state emission (DSE) luminogens containing the V-shape furo[2, 3-b]furan scaffold
Jie Zhou , Manna Huang , Xinhai Zhu , Yiqian Wan
2021, 32(1): 445-448  doi: 10.1016/j.cclet.2020.02.038
[Abstract](280) [FullText HTML] [PDF 805KB](2)
To discover novel fluorophores of solution and solid dual-state emission (DSE) materials, unique V-shape furo[2, 3-b]furans have been designed and synthesized by a one-pot method for the first time and their photoluminescent properties have been explored in benzene, THF, DMF and DMSO, as well as in the solid state. As the best example, 2, 5-bis(4-(9H-carbazol-9-yl)phenyl)-6a-amino-3a, 6a-dihydrofuro[2, 3-b] furan-3, 3a, 4-tricarbonitrile (3g) exhibited solution and solid DSE properties in THF, benzene, and in the solid state with quantum yields of 55%, 92%, and 45%, respectively.
Cycloadditions of 1-iminylphosphirane complexes with allenes
Juan Li , Mingyue Cui , Rongqiang Tian , Zheng Duan , François Mathey
2021, 32(1): 449-452  doi: 10.1016/j.cclet.2020.05.026
[Abstract](210) [FullText HTML] [PDF 773KB](1)
A cascade carbonylative ring expansion and [2 + 2]/[4 + 2] cycloaddition of strained 1-iminylphosphirane complexes with aryl allenes were reported. The carbonylative ring expansion of 1-iminylphosphirane complexes provides an azaphosphacyclohexone complex intermediate with a C=P double bond. The following [2 + 2] or dearomatic [4 + 2] cycloaddition of this intermediate with allenes is modulated by the aryl substituents on the imino carbon. The regioselective [2 + 2] cycloaddition with 1, 1-diarylallene provides an entry to bicyclo[4.2.0]octan-4-one skeletons featuring a four-membered phosphacyclobu-tane moiety. While dearomatic [4 + 2] cycloaddition was preferred with less aromatic naphthalene and yielded octahydrochrysene skeleton containing heteroatoms.
Synthesis of S-monofluoromethyl phosphorothioates from PV-H compounds and PhSO2SCH2F
Renyi Pang , Ruichao Yao , Shiyao Lu , Yicheng Zhou , Wenbo Chen
2021, 32(1): 453-456  doi: 10.1016/j.cclet.2020.05.032
[Abstract](269) [FullText HTML] [PDF 719KB](2)
S-Monofluoromethyl phosphorothioates represent an important class of organofluorine compounds and are reported here for the first time. A series of S-monofluoromethyl phosphorothioates are conveniently synthesized from different PV-H compounds and PhSO2SCH2F under mild conditions. The method is compatible with common functional groups and provides potential opportunities to synthesize new bioactive molecules for medicinal chemistry.
Thiophene and naphthalene-based double helix: Synthesis, structures and chirality
Chunmei Zhao , Zhiying Ma , Chunli Li , Li Xu , Hua Wang
2021, 32(1): 457-460  doi: 10.1016/j.cclet.2020.05.040
[Abstract](188) [FullText HTML] [PDF 895KB](2)
Both racemate and enantiomer of a novel double helix, binaphthylcyclooctaterthiophene (BN—COTh), which is a DNA-like molecule constructed by two single helices intertwined with each other via covalent bonds, have been synthesized with two building blocks, cycloocta-tetrathiophene (COTh) and cyclooctadinaphthyldithiophene (CONT) fused together via Negishi coupling reaction. Another homologue, dinaphthylcyclooctaterthiophene (DN-COTh) has been employed together as a model compound. Besides the synthetic work, BN—COTh and DN-COTh have been investigated by studying their crystal structures, spectroscopic behaviors, chiral resolution and chiral characteristics, including circular dichroism (CD) spectra and optical rotations. In addition, the novel crystal of enantiomer of (R, R, R)-BN—COTh has been explored. The enantiomer molecules packing along b-axis to form a larger and extended assembly packing due to intermolecular interactions between the enantiomer molecules and chloroform molecules in crystal.
Sulfonylation from sodium dithionite or thiourea dioxide
Fu-Sheng He , Min Yang , Shengqing Ye , Jie Wu
2021, 32(1): 461-464  doi: 10.1016/j.cclet.2020.04.043
[Abstract](307) [FullText HTML] [PDF 1099KB](7)
The cheap and easily available sodium dithionite and thiourea dioxide have been used as the source of sulfonyl group in the synthesis of sulfones and sulfonamides recently. Compared with other methods for the sulfonylation reactions, the strategies using sodium dithionite or thiourea dioxide provide an alternative and complementary route to diverse sulfonyl compounds. During the reaction process, sulfur dioxide anion radical is the key intermediate, which is usually generated from a single electron transfer under suitable conditions. The advantages using sodium dithionite or thiourea dioxide in the sulfonylation reactions include mild conditions and broad substrate scope with excellent functional group compatibility. Further applications by using sodium dithionite and thiourea dioxide in organic transformations will be anticipated.
Nano palladium catalyzed C(sp3)—H bonds arylation by a transient directing strategy
Jianxia Chen , Chaolumen Bai , Hongpeng Ma , Dan Liu , Yong-Sheng Bao
2021, 32(1): 465-469  doi: 10.1016/j.cclet.2020.02.055
[Abstract](206) [FullText HTML] [PDF 1025KB](1)
Reported herein is the first example of heterogeneous palladium catalyzed C(sp3)-H bonds arylation by a transient-ligand-directed strategy. Using supported palladium (metallic state) nanopariticles as catalyst, a wide range of aryl iodides undergo the coupling with various o-methylbenzaldehyde derivatives to assemble a library of highly selective and functionalized o-benzylbenzaldehydes. The stability of the catalyst was easily recovered four runs without significant loss of activity. The XPS analysis of the catalyst before and after reaction indicated that the reaction might be carried out by a catalytic cycle starting with Pd0.
Weakly coordinating group directed rhodium-catalyzed unconventional site-selective C–H olefination of indolizines at the 8-position
Xue Feng , Jiaxin Tian , Ying Sun , Huayou Hu , Mingzhu Lu , Yuhe Kan , Danjun Fang , Chao Wang
2021, 32(1): 470-474  doi: 10.1016/j.cclet.2020.02.039
[Abstract](250) [FullText HTML] [PDF 856KB](4)
A rhodium-catalyzed directing group promoted selective C–H olefination reaction of indolizines at the 8-position is reported. Di-olefination at 2,8-positions also achieved with silver hexafluoroantimonate as an additive under similar reaction conditions. Weakly coordinating groups, such as ketone, aldehyde, amide and ester, were used as directing groups. The ester group can be removed under acid conditions and therefore is used as a traceless directing group.
Practical and sustainable approach for clean preparation of 5-organylselanyl uracils
Jin-Yang Chen , Chun-Tao Zhong , Qing-Wen Gui , Yuan-Ming Zhou , Yang-Yang Fang , Kai-Jian Liu , Ying-Wu Lin , Zhong Cao , Wei-Min He
2021, 32(1): 475-479  doi: 10.1016/j.cclet.2020.09.034
[Abstract](304) [FullText HTML] [PDF 1034KB](2)
An eco-friendly, sustainable and practical method for the efficient preparation of 5-organylselanyl uracils through the electrochemical selenylation of uracils and diorganyl diselenides at room temperature under oxidant- and external electrolyte-free conditions was developed.
Structural transformations of carboxyl acids networks induced by concentration and oriented external electric field
Wei Li , Shilin Xu , Xiaoling Chen , Chengyong Xu
2021, 32(1): 480-484  doi: 10.1016/j.cclet.2020.06.012
[Abstract](254) [FullText HTML] [PDF 946KB](1)
The effects of concentration and an oriented external electric field on the transformations of hydrogenbonded structures of trimesic acid (TMA) and terephthalic acid (TPA) have been investigated at a liquid–solid interface by scanning tunneling microscopy (STM). The triangular periodic TMA framework can be transformed into a flower-like structure by changing the STM sample bias sign in situ. Networks of TMA and TPA are porous at a negative substrate bias, but typically change to relatively compact forms when the polarity of the applied bias is reversed. This change is reversible if the applied bias is reversed. The effects have potentials to locally control the capture and release of analytes in host-guest systems and the 2D morphology in multicomponent layers.
Coordination-driven self-assembly of palladium(Ⅱ)-based metallacalixarenes as anion receptors using flexible pyridine-bridged diimidazole ligands
Wutong Du , Jin Tong , Wei Deng , Mingxue Wang , Shuyan Yu
2021, 32(1): 485-488  doi: 10.1016/j.cclet.2020.03.053
[Abstract](221) [FullText HTML] [PDF 767KB](1)
Two types of palladium(Ⅱ)-based metallacalixarenes [ML]2+ and [ML2]2+ have been synthesized through coordination-driven self-assembly from a series of flexible pyridine-bridged diimidazole ligands [2,6-bis ((1H-imidazol-1-yl)methyl) pyridine (L1), 2,6-bis((1H-benzo[d]imidazol-1-yl)methyl)pyridine (L2), 2,6-bis((1H-naphtho[2,3-d]imidazol-1-yl)methyl)pyridine (L3)], with palladium(Ⅱ)-based building blocks [Pd(BF4)2(M1-BF4) and (tmeda)Pd(NO3)2 (M2-NO3) (tmeda = N, N, N', N'-tetramethyl-ethylenediamine)]. All complexes were characterized by NMR spectroscopy (1H NMR and 13C NMR), mass spectrometry (CSI-MS, ESI-HRMS) and elemental analysis. The single crystal X-ray diffraction analysis of [M1L22](NO3)2, [M1L23](NO3)2, [M1L23](PF6)2 and [M2L3](NO3)2 further confirmed the uniquely single bowl-shape and double bowl-shape structures. The anion binding properties within the metallacalixarenes as receptors were also investigated by NMR titration experiments in DMSO.
Chemical vapor deposition growth of phase-selective inorganic lead halide perovskite films for sensitive photodetectors
Weilong Xu , Mengsi Niu , Xiaoyu Yang , Haiyue Chen , Xiaohong Cai , Trevor A. Smith , Kenneth P. Ghiggino , Xiaotao Hao
2021, 32(1): 489-492  doi: 10.1016/j.cclet.2020.05.017
[Abstract](222) [FullText HTML] [PDF 974KB](3)
Inorganic lead halide perovskites are attractive optoelectronic materials owing to their relative stability compared to organic cation alternatives. The chemical vapor deposition (CVD) method offers potential for high quality perovskite film growth. The deposition temperature is a critical parameter determining the film quality owing to the melting difference between the precursors. Here, perovskite films were deposited by the CVD method at various temperatures between 500-800 ℃. The perovskite phase converts from CsPb2Br5 to CsPbBr3 gradually as the deposition temperature is increased. The grain size of the perovskite films also increases with temperature. The phase transition mechanism was clarified. The photoexcited state dynamics were investigated by spatially and temporally resolved fluorescence measurements. The perovskite film deposited under 750 ℃ condition is of the CsPbBr3 phase, showing low trap-state density and large crystalline grain size. A photodetector based on perovskite films shows high photocurrent and an on/off ratio of ~2.5×104.
Stimuli-responsive cyclometalated platinum complex bearing bent molecular geometry for highly efficient solution-processable OLEDs
Zhenhua Wei , Kai Zhang , Chan Kyung Kim , Shuai Tan , Shaojie Wang , Lin Wang , Jun Li , Yafei Wang
2021, 32(1): 493-496  doi: 10.1016/j.cclet.2020.05.005
[Abstract](248) [FullText HTML] [PDF 789KB](3)
Smart materials, such as stimuli-responsive luminescence, have attracted much attentions due to their potential application in semiconductorfiled. In this context, platinumcomplexes of (dfppy-DC)Pt(acac) and (dfppy-O-DC)Pt(acac) were prepared and characterized, in which (2-(4', 6'-difluorophenyl)pyridinato-N, C2')(2,4-pentanedionato-O, O)Pt(Ⅱ) was used as the planar emission core and 9-(4-(phenylsulfonyl) phenyl)-9H-carbazole (DC) was regard as the bent pendent. Both platinum complexes showed bright emission in solution and solid state, concomitant with charming external-stimuli-responsive emission under mechanical grinding, organic solvent vapors and pressure. The change emission color spanned from yellow to near-infrared region. Using the platinum complexes as the dopant, solution processable organic light-emitting diodes (OLEDs) were fabricated and a maximum external quantum efficiency of ~18% was achieved, which is the highest value among the reported solution-processable OLEDs based on external-stimuli-responsive luminescence.This research demonstrated that platinum complex can show promising stimuli responsive emission via ingenious molecular design, indicating a novel way for developing the smart materials in semiconductor filed.
Microplasma electrochemistry (MIPEC) strategy for accelerating the synthesis of metal organic frameworks at room temperature
Guoyu Wei , Yuexiang Lu , Shuang Liu , Hongpeng Li , Xuegang Liu , Gang Ye , Jing Chen
2021, 32(1): 497-500  doi: 10.1016/j.cclet.2020.04.019
[Abstract](283) [FullText HTML] [PDF 815KB](2)
Metal organic frameworks (MOFs) are a kind of promising materials in many applications, while the fast and controllable synthesis of MOFs is still challenging. Here, taking HKUST-1 as illustration, a micro-plasma electrochemistry (MIPEC) strategy was developed to accelerate the synthesis process of MOFs with micro-plasma acting as cathode. Treating the HKUST-1 precursor solution with micro-plasma cathode could not only transfer the electrons into the solution leading to the deprotonation effect, but also generate radical species to trigger and accelerate the nucleation and growth of MOFs at the plasma-liquid interface. Thus, uniform and nanosize MOFs could be prepared within minutes. The obtained MOFs show similar excellent uranium adsorption properties compared with those obtained by other method, with a highly adsorption capability of uranium with 550 mg/g in minutes. The novel MIPEC strategy developed in this work provides an alternative for controllable synthesis of MOFs, and especially has potential application in accelerating traditional organic synthesis.
Layer-by-layer stacked graphene nanocoatings by Marangoni self-assembly for corrosion protection of stainless steel
Chen Ye , Yangguang Zhu , Hongyan Sun , Feiyue Chen , Huifang Sun , Wen Dai , Qiuping Wei , Li Fu , Aimin Yu , Shiyu Du , Minghui Yang , Liang-Feng Huang , Jinhong Yu , Nan Jiang , Cheng-Te Lin
2021, 32(1): 501-505  doi: 10.1016/j.cclet.2020.03.013
[Abstract](238) [FullText HTML] [PDF 907KB](4)
Graphene nanosheets are widely used in anti-corrosion polymeric coating as filler, owing to the excellent electrochemical inertness and barrier property. However, as the arrangement of graphene nanosheets is difficult to form a perfect layered structure, polymeric coating with graphene nanosheets usually needs micron-scale thickness to ensure the enhancement of corrosion protection. In this work, layer-by-layer stacked graphene nanocoatings were fabricated on stainless steel by self-assembly based on Marangoni effect. The anti-corrosion property of graphene coatings were studied through Tafel polarization curves, electrochemical impedance spectroscopy and accelerated corrosion test with extra applied voltage. The self corrosion current density of optimized three-layered graphene coated sample was one quarter of that of bare stainless steel. And the self corrosion potential of optimized sample is increased to -0.045 V. According to the results, graphene nanocoatings composed of layered nanosheets exhibits good anti-corrosion property. Besides, the self-assembly method provide a promising approach to make layered-structure coating for other researches about 2D material nanosheets.
Fe, Cu-codoped metal-nitrogen-carbon catalysts with high selectivity and stability for the oxygen reduction reaction
Yuemin Wang , Ergui Luo , Xian Wang , Qinglei Meng , Junjie Ge , Changpeng Liu , Wei Xing
2021, 32(1): 506-510  doi: 10.1016/j.cclet.2020.03.061
[Abstract](231) [FullText HTML] [PDF 1613KB](2)
Metal-nitrogen-carbon materials (M-N-C) are non-noble-metal-based alternatives to platinum-based catalysts and have attracted tremendous attention due to their low-cost, high abundance, and efficient catalytic performance towards the oxygen reduction reaction (ORR). Among them, Fe-based materials show remarkable ORR activity, but they are limited by low selectivity and low stability. To address these issues, herein, we have synthesized FeCu-based M-N-C catalysts, inspired by the bimetal center of cytochrome c oxidase (CcO). In acidic media, the selectivity was notably improved compared with Fe-based materials, with peroxide yields less than 1.2% (< 1/3 of the hydrogen peroxide yields of Fe-N-C catalysts). In addition to Cu-N-C catalysts which can catalytically reduce hydrogen peroxide, the reduction current of hydrogen peroxide using FeCu-N-C-20 exceeded that of Fe-N-C by about 6% when the potential was greater than 0.4 V. Furthermore, FeCu-based M-N-C catalysts suffered from only a 15 mV attenuation in their half-wave potentials after 10, 000 cycles of accelerated degradation tests (ADT), while there was a 30 mV negative shift for Fe-N-C. Therefore, we propose that the H2O2 released from Fe-Nx sites or N-doped carbon sites would be reduced by adjacent Cu-Nx sites, resulting in low H2O2 yields and high stability.
Ruthenium nanoclusters anchored on cobalt phosphide hollow microspheres by green phosphating process for full water splitting in acidic electrolyte
Yunqie Deng , Linjing Yang , Yakun Wang , Lili Zeng , Jiayuan Yu , Bo Chen , Xiaoli Zhang , Weijia Zhou
2021, 32(1): 511-515  doi: 10.1016/j.cclet.2020.03.076
[Abstract](265) [FullText HTML] [PDF 1062KB](3)
Transition metal phosphide (TMP) based electrocatalysts possessing special crystal and electronic structures attract broad attention in the field of electrocatalysis. Immense effort is made to optimize TMP catalysts aiming to satisfy the electrochemical catalysis performance. In this work, an environmentally friendly in situ green phosphating strategy and spatial limiting effect of the RuCo precursor is employed to fabricate the ruthenium nanoclusters anchored on cobalt phosphide hollow microspheres (Ru NCs/Co2P HMs). The obtained Ru NCs/Co2P HMs electrocatalysts exhibit high hydrogen evolution reaction (HER) activity at wide pH ranges, which require an overpotential of 77 mV to achieve the current density of 10 mA/cm2 in 0.5 mol/L H2SO4 and 118 mV in 1.0 mol/L KOH. Besides, the multifunctional Ru NCs/Co2P HMs exhibit good oxygen evolution reaction (OER) activity with an overpotential of 197 mV to reach the current density of 10 mA/cm2 in 0.5 mol/L H2SO4, which is below that of the commercial RuO2 electrocatalyst (248 mV). A two-electrode electrolyzer is assembled as well, in acid electrolyte, it achieves a current density of 10 mA/cm2 at a voltage of 1.53 V, which is superior to that of the benchmark of precious metal-based electrolyzer (1.58 V).
Cooperation between Pt and Ru on RuPt/AC bimetallic catalyst in the hydrogenation of phthalates
Yan Xu , Chenguang Wu , Yan Wang , Ying Zhang , Han Sun , Haijun Chen , Yujun Zhao
2021, 32(1): 516-520  doi: 10.1016/j.cclet.2020.04.016
[Abstract](196) [FullText HTML] [PDF 869KB](4)
RuPt/AC bimetallic catalysts were prepared by two-step incipient impregnation method and evaluated in the hydrogenation of phthalates. According to the characterization results, well dispersed RuPt bimetallic nanoparticles were formed on the catalyst, and the strong interaction between the two metals resulted in the formation of RuPt alloy. It was found that Ru can donate electrons to Pt on RuPt alloy nanoparticles, leading to the formation of electron-deficient Ru which significantly promotes the hydrogenation rate of dioctyl phthalate and improves the selectivity of dioctyl di-2-ethylhexylcyclohexane-1, 4-dicarboxylate by accelerating the further hydrogenation of intermediate products. The bimetallic RuPt catalyst also presented excellent stability and versatility in the hydrogenation of phthalates, demonstrating its prospective future in the hydrogenation of aromatic ring contained compounds.
Super-tough and rapidly self-recoverable multi-bond network hydrogels facilitated by 2-ureido-4[1H]-pyrimidone dimers
Hao Xu , Xu-Ming Xie
2021, 32(1): 521-524  doi: 10.1016/j.cclet.2020.04.039
[Abstract](218) [FullText HTML] [PDF 856KB](4)
Multi-bond network (MBN) hydrogels contain hierarchical dynamic bonds with different bond association energy as energy dissipation units, enabling super-tough mechanical properties. In this work, we copolymerize a protonated 2-ureido-4[1H]-pyrimidone (UPy)-contained monomer with acrylic acid in HCl solution. After removing excess HCl, UPy motifs are deprotonated and from dimers, thus generating an UPy-contained MBN hydrogel. The obtained MBN hydrogels (75 wt% water content) exhibit super-tough mechanical properties (0.39 MPa to 2.51 MPa tensile strength), with tremendous amount of energy (1.68 MJ/m3 to 11.1 MJ/m3) dissipated by the dissociation of UPy dimers. The introduction of ionic bonds can further improve the mechanical properties. Moreover, owing to their dynamic nature, both UPy dimers and ionic bonds can re-associate after being dissociated, resulting in excellent self-recovery ability (around 90% recovery efficiency within only 1 h). The excellent self-recovery ability mainly originates from the re-association of UPy dimers based on the high dimerization constant of UPy motifs.
Solvent induced enhancement of nonlinear optical response of graphdiyne
Yuze Dong , Sergey Semin , Yaqing Feng , Jialiang Xu , Theo Rasing
2021, 32(1): 525-528  doi: 10.1016/j.cclet.2020.03.078
[Abstract](209) [FullText HTML] [PDF 869KB](5)
Flat and crystalline materials with exceptional nonlinear optical (NLO) properties are highly desirable for their potential applications in integrated NLO photonic devices. Graphdiyne (GD), a new two-dimensional (2D) carbon allotrope, has recently evoked burgeoning research attention by virtue of its tunable bandgap along with a high carrier mobility and extended π-conjugation compared with most conventional optical materials. Here, we experimentally probe the third-order nonlinear optical response of GD dispersed in several common solvents (alcohols) using a femtosecond Z-scan technique. The measured nonlinear optical refractive index is in the order of ~10-8 cm2/W, which is approximately one order of magnitude higher than that of most 2D materials. In particular, we find that different NLO responses can be observed from GD when dispersed in different solvents, with the strongest NLO response when dispersed in 1-propanol. It is proposed that some intrinsic properties of the solvents, such as the polarity and viscosity, could influence the NLO response of GD materials. Our experimental results confirm the assumptions on the NLO behavior in GD and demonstrate its great potential for future generations of Kerr-effect-based NLO materials and devices.
Influence of donor: acceptor ratio on charge transfer dynamics in non-fullerene organic bulk heterojunctions
Zhenchuan Wen , Tong Wang , Zhihao Chen , Tingting Jiang , Lin Feng , Xianjin Feng , Chaochao Qin , Xiaotao Hao
2021, 32(1): 529-534  doi: 10.1016/j.cclet.2020.02.013
[Abstract](218) [FullText HTML] [PDF 1320KB](3)
The donor: acceptor (D: A) blend ratio plays a very important role in affecting the progress of charge transfer and energy transfer in bulk heterojunction (BHJ) organic solar cells (OSCs). The proper D: A blend ratio can provide maximized D/A interfacial area for exciton dissociation and appropriate domain size of the exciton diffusion length, which is beneficial to obtain high-performance OSCs. Here, we comprehensively investigated the relationship between various D: A blend ratios and the charge transfer and energy transfer mechanisms in OSCs based on PBDB-T and non-fullerene acceptor IT-M. Based on various D: A blend ratios, it was found that the ratio of components is a key factor to suppress the formation of triplet states and recombination energy losses. Rational D: A blend ratios can provide appropriate donor/accepter surface for charge transfer which has been powerfully verified by various detailed experimental results from the time-resolved fluorescence measurement and transient absorption (TA) spectroscopy. Optimized coherence length and crystallinity are verified by grazing incident wide-angle X-ray scattering (GIWAXS) measurements. The results are beneficial to comprehend the effects of various D: A blend ratios on charge transfer and energy transfer dynamics and provides constructive suggestions for rationally designing new materials and feedback for photovoltaic performance optimization in non-fullerene OSCs
A new strategy to access Co/N co-doped carbon nanotubes as oxygen reduction reaction catalysts
Bingshuai Liu , Huang Zhou , Huihui Jin , Jiawei Zhu , Zhe Wang , Chenxi Hu , Lvhan Liang , Shichun Mu , Daping He
2021, 32(1): 535-538  doi: 10.1016/j.cclet.2020.04.002
[Abstract](240) [FullText HTML] [PDF 855KB](4)
Carbon nanotubes (CNTs), as one-dimensional nanomaterials, show great potential in energy conversion and storage due to their efficient electrical conductivity and mass transfer. However, the security risks, time-consuming and high cost of the preparation process hinder its further application. Here, we develop that a negative pressure rather than a following gas environment can promote the generation of cobalt and nitrogen co-doped CNTs (Co/N-CNTs) by using cobalt zeolitic imidazolate framework (ZIF-67) as a precursor, in which the negative pressure plays a key role in adjusting the size of cobalt nanoparticles and stimulating the rearragement of carbon atoms for forming CNTs. Importantly, the obtained Co/N-CNTs, with high content of pyridinic nitrogen and abundant graphitized structure, exhibit superior catalytic activity for oxygen reduction reaction (ORR) with half-wave potential (E1/2) of 0.85 V and durability in terms of the minimum current loss (2%) after the 30, 000 s test. Our development provides a new pathway for large-scale and cost-effective preparation of metal-doped CNTs for various applications.
High-temperature dielectric switch and second harmonic generation integrated in a stimulus responsive material
Yingsong Xue , Zhixu Zhang , Pingping Shi , Wanying Zhang , Qiong Ye , Dawei Fu
2021, 32(1): 539-542  doi: 10.1016/j.cclet.2020.02.005
[Abstract](199) [FullText HTML] [PDF 793KB](4)
Stimulus responsive materials can provide a variety of desirable properties in one equipment unit, such as optoelectronic devices, data communications, actuators, memories, sensors and capacitors. However, it remains a large challenge to design such stimulus responsive materials, especially functional materials having both dielectric switch and second harmonic generation (SHG). Here, a new stimuli-responsive switchable material [(CH3)3N(CH2)2Cl]2[Mn(SCN)4(H2O)2] was discovered as a potential second-harmonic generation (SHG) dielectric switch. It is worth noting that it has SHG characteristics before and after undergoing reversible high-temperature phase transitions. In this work, we successfully refined the tetramethylammonium cation to obtain a quasi-spherical cation, which is tetramethylchloroethyl-amine (TMCEM) cation. By substituting H with a halogen, the increased steric hindrance of the molecular makes energy barrier increased, resulting in the reversible high-temperature phase transition. At the same time, the interactions of quasi-spherical cations and [Mn(SCN)4(H2O)2]2- anions affect a non-centrosymmetric structure to induce the SHG effect. These findings provide a new approach to design novel functional switch materials.
Ultrafast room-temperature reduction of graphene oxide by sodium borohydride, sodium molybdate and hydrochloric acid
Jun Hu , Gang Kong , Yanbin Zhu , Chunshan Che
2021, 32(1): 543-547  doi: 10.1016/j.cclet.2020.03.045
[Abstract](220) [FullText HTML] [PDF 969KB](2)
Since graphene-based materials have shown great potential in many fields, it is important to explore ultrafast and high-efficient methods to synthesize reduced graphene oxide (rGO) using inexpensive reducing agents under mild conditions. Here, we reported a novel method for the ultrafast chemical reduction of graphene oxide (GO) at room temperature using sodium borohydride (NaBH4), sodium molybdate (Na2MoO4) and hydrochloric acid (HCl). The reduction was carried out within 2 min. A series of characterization results revealed that the obtained reduced graphene oxide has higher reduction degree than that synthesized by NaBH4 alone at high temperature. Moreover, rGO electrode based on the present reducing method exhibited a superior specific capacitance of 139.8 F/g at a current density of 1 A/g, indicating that it can be used as electrode materials for supercapacitors.
Tunable UCST thermoresponsive copolymers based on natural glycyrrhetinic acid
Yiran Zhao , Jingyao Ma , Xia Yu , Min-Hui Li , Jun Hu
2021, 32(1): 548-552  doi: 10.1016/j.cclet.2020.03.057
[Abstract](208) [FullText HTML] [PDF 842KB](2)
Water-soluble thermoresponsive polymers present either upper critical solution temperature (UCST) or lower critical solution temperature (LCST) depending on the location of their miscibility range with water at high temperatures or at low temperatures. Compared with LCST polymers, the water-soluble UCST polymers are still less explored until now. In this work three copolymers of P(AAm-co-GAA) were synthesized by copolymerizing two acrylamide monomers, acrylamide (AAm) and acrylamide functionalized with natural glycyrrhetinic acid (GAA), using reversible addition-fragmentation chain transfer (RAFT) polymerization. These copolymers exhibited the typical UCST thermoresponsive behavior, and their phase transition temperatures could be easily tuned to around 37 ℃ for potential biological applications. Moreover, the UCST of P(AAm-co-GAA) can be adjusted not only by the content of glycyrrhetinic acid (GA) and polymer concentrations, but also by the host-guest interactions between GA and cyclodextrins (β- and γ-CD). The suitable value of UCST and the biocompatible nature of GA and CDs may endow these copolymers with practical applications in biomedical chemistry
Reversible adhesion surface coating proppant
Quan Xu , Fan Fan , Zhaohui Lu , Mao Sheng , Shouceng Tian , Ye Zhang , Linhua Pan , Yang Zhou
2021, 32(1): 553-556  doi: 10.1016/j.cclet.2020.02.014
[Abstract](238) [FullText HTML] [PDF 896KB](1)
Proppant is a key material in the hydraulic fracturing process, which has been widely used in unconventional oil exploitation. Normal proppants are easy to sedimentate and accumulate at the entrance of shale fracture, which will block the diversion of water, oil and gas. Coated proppants (CPs) are fabricated by coating resin on normal ceramic proppants through a simple method, which is dramatically enhanced the supporting properties in shale fracture and easy to scale up. Compared with uncoated ceramic proppants, the self-suspension ability of CPs is ~11 times higher, which are able to migrate and distribute farther and deeper inside the fracture. At the same time, Coating enhanced the 23.7% of adhesive force in maximum, which makes the CPs easier to adhere on the fracture surface to supportthe shale fracture. Besides, the liquid conductivity of CPs is 60% higher than uncoated ceramic proppants at 13.6 MPa pressure. This method is expected to fabricated varieties of proppantsfor shale fracture supporting to improve the exploration of unconventional oil and gas resources.
Two isostructural Ni(Ⅱ)/Co(Ⅱ)-based metal-organic frameworks for selective dye adsorption and catalytic cycloaddition of CO2 with epoxides
Hui Hu , Dashuai Zhang , Huiling Liu , Yaoqiang Jin , Jun Gao , Yongzheng Zhang , Zhongmin Liu , Xiuling Zhang , Longlong Geng , Suijun Liu , Ranhui Zhang
2021, 32(1): 557-560  doi: 10.1016/j.cclet.2020.02.028
[Abstract](182) [FullText HTML] [PDF 854KB](2)
Two isostructural Ni(Ⅱ)/Co(Ⅱ)-based metal-organic frameworks (MOFs), namely {[M3(L)2(bpb)3(H2O)4]·2DMF·2H2O}n [M = Ni (HL-5, HL is short for Hui-Ling Liu); M = Co (HL-6); H3L = 2', 6'-dimethyl-[1, 1'-biphenyl]-3, 4', 5-tricarboxylic acid; bpb = 1, 4-bis(pyrid-4-yl)benzene], have been hydrothermally syn-thesized and structurally characterized. Both HL-5 and HL-6, which have the same three-interpenetrated 3D pillared-layer framework with sqc306 type topology, present good selective methyl orange (MO) adsorption over rhodamine B (RhB). Moreover, the catalytic CO2 cycloaddition properties with epoxides of the two MOFs have also been studied at ambient pressure and temperature.
Stimuli-responsive dual drugs-conjugated polydopamine nanoparticles for the combination photothermal-cocktail chemotherapy
Lei Zhou , Chang Du , Rong Zhang , Changming Dong
2021, 32(1): 561-564  doi: 10.1016/j.cclet.2020.02.043
[Abstract](203) [FullText HTML] [PDF 935KB](2)
We developed one-pot aqueous copolymerization of two dopamine prodrugs to prepare dual drugs-conjugated polydopamine nanoparticles (PDOXCBs), which integrated near infrared (NIR)-mediated photothermal effect with cocktail chemotherapy into one copolymer nanoparticle. Upon a mild NIR irradiation (808 nm, 1 W/cm2, 10 min), PDOXCBs gradually heated aqueous solution over 12.8–13.9 ℃, which accordingly enhanced in vitro dual doxorubicin (DOX) and chlorambucil (CB) drug-release with assistance of the other stimuli of pH 5.0 and 10 mmol/L D,L-dithiothreitol (DTT). The combination photothermal-cocktail chemotherapy (PTT-CCT) treatment based on PDOXCB27 plus NIR irradiation gave a highly lowered half maximal inhibitory concentration (IC50) of 2.23 μg/mL and a combination index of 0.36, displaying a superior synergistic effect between PTT and CCT in vitro.
Synthesis and structure of Au19Ag4(S-Adm)15 nanocluster: Polymorphs and optical properties
Xuemei Fu , Xinzhang Lin , Xiuqing Ren , Hengjiang Cong , Chao Liu , Jiahui Huang
2021, 32(1): 565-568  doi: 10.1016/j.cclet.2020.02.041
[Abstract](180) [FullText HTML] [PDF 814KB](1)
Polymorphism is a common phenomenon in nature. Here, we report one-pot wet chemical method to synthesize two polymorphs of Au19Ag4(S-Adm)15 nanocluster protected by 1-adamantanethiol (HS-Adm), which adopt P-1 and P21/c space group respectively. The crystal structures of two polymorphs were determined by X-ray crystallography. Compared to the previously reported Au19Ag4(S-Adm)15 nanocluster adopting P21/n space group, polymorphs of Au19Ag4(S-Adm)15 with P-1 and P21/c space group show the different optical properties. Moreover, Au19Ag4(S-Adm)15 with P-1 space group exhibits good thermal stability. Meanwhile, we investigated the effect of solvent and molar ratio of metal precursors on the polymorphs. This work provides an insight to polymorphs of metal nanoclusters.
Construction of a nano-rectangular Zn-Nd complex with near-infrared luminescent response towards metal ions
Xia Liu , Xiaoping Yang , Yanan Ma , Jieni Liu , Dongliang Shi , Desmond Schipper
2021, 32(1): 569-572  doi: 10.1016/j.cclet.2020.03.016
[Abstract](186) [FullText HTML] [PDF 779KB](1)
One 6-metal Zn-Nd complex [Zn2Nd4L2(OAc)10(OH)2(CH3OH)2] (1) with Schiff base ligand bis(3-methoxysalicylidene)ethylene-1,2-phenylenediamine (H2L) was constructed, and it has nanoscale rectangular structure (8×11×28 Å). Excited by ligand-centered absorption bands, 1 shows NIR emission of Nd3+ ion. Interestingly, 1 exhibits lanthanide luminescent response towards metal ions, especially to alkali metal ions (Li+, Na+ and K+) at ppm level.
Zwitterionic comb-like lipid polymers encapsulating linalool for increasing the fragrance retention time
Tianlu Zhang , Zhiguo Lu , Xiangyu Wang , Jie Shen , Jianze Wang , Yunwei Niu , Zuobing Xiao , Xin Zhang
2021, 32(1): 573-576  doi: 10.1016/j.cclet.2020.01.041
[Abstract](166) [FullText HTML] [PDF 782KB](1)
Fragrances are widely used in cosmetics, apparel and detergents. However, the rapid evaporation of the aroma shortens the useful life of the aromatic product. Therefore, improving the fragrance retention time of aromatic products and prolonging the service life of aromatic products are the key scientific problems that need to be solved in current aromatic products. In this study, zwitterionic comb-like lipid polymers were synthesized to encapsulate the fragrance molecule linalool. The results showed that the zwitterionic comb lipid molecules were capable of encapsulating more linalool than linear lipid molecules. At the same time, the zwitterionic comb-like lipid molecules also limited the slow release rate of the aroma, thereby increasing the fragrance retention time of the nano-fragrance.
Superiority of poly(L-lactic acid) microspheres as dermal fillers
Quan Gao , Lijie Duan , Xiangru Feng , Weiguo Xu
2021, 32(1): 577-582  doi: 10.1016/j.cclet.2020.03.071
[Abstract](349) [FullText HTML] [PDF 1249KB](11)
The demand for injectable dermal filler has undergone significant growth with the rapid development of the beauty industry. Poly(lactic acid) (PLA) as a benefit of excellent biocompatibility and long-term promotion of collagen regeneration has been favored as a commonly used filler. However, the effects of chirality and particle size of PLA on the efficacy of dermal filler have not been studied. In this study, we prepared three kinds of microspheres (MSs) consisting of poly(D-lactic acid) (PDLA MS), poly(L-lactic acid) (PLLA MS), or meso-PLA (PDLLA MS) at 5, 10 and 20 μm to reveal the different biological functions as dermal filler. Following intradermal injection into guinea pig, it was found that PLLA MS induced the slightest inflammation, and the level of pro-inflammatory cytokine IL-1β induced by PLLA MS is only 0.3 or 0.7-fold of that induced by PDLA or PDLLA MS, respectively. More importantly, PLLA MS significantly stimulated the regeneration of collagen, which was 1.4 or 1.1 times higher than those stimulated by PDLA MS or PDLLA MS, respectively. The size of PLA MSs did not affect the levels of inflammation and collagen regeneration. The results confirmed the superiority of PLLA as a dermal filler.
Hydrothermal-assisted grinding route for WS2 quantum dots (QDs) from nanosheets with preferable tribological performance
Zhi-Lin Cheng , Lu Ma , Zan Liu
2021, 32(1): 583-586  doi: 10.1016/j.cclet.2020.02.002
[Abstract](264) [FullText HTML] [PDF 826KB](2)
The 2D nanomaterials have achieved the superlubrication property whatever in solid or liquid lubrication in recent years. However, whether or not the nanosheets can stably disperse in oils and smoothly enter into the asperity of friction pairs is crucial for exerting the function of antifriction. The structure of 2D QDs is desirable for addressing these issues due to its smaller 3D size. In this study, we developed a facile preparation process for WS2 QDs with uniform 2 nm size from nanosheets via hydrothermal-assisted grinding approach. The structure of the as-obtained WS2 QDs was determined by a series of characterizations. The results showed that the as-obtained WS2 QDs exhibited the typical spectrum features of nanosized quantum dot. The results of the tribological performance in grease verified that the average friction coefficient (ACOFs) and wear volume (AWVs) were decreased by 7.89% and 63.90% relative to grease, respectively, exhibiting a preferable friction reducing and wear resistance.
A biomass based photonic crystal made of "konjac tofu"
Wenxin Zhang , Min Xue , Kenneth J. Shea , Lili Qiu , Zhibin Xu , Jing Fan , Dan Yan , Zihui Meng
2021, 32(1): 587-590  doi: 10.1016/j.cclet.2020.03.012
[Abstract](207) [FullText HTML] [PDF 854KB](1)
Konjac tofu is a traditional Chinese food whose main ingredient is the water-soluble polysaccharide from konjac tubers-konjac glucomannan (KGM). Herein we report an interpenetrating double network polymeric film by crosslinking KGM and polyvinyl alcohol (PVA) with glutaraldehyde under acidic conditions. PVA was introduced into the hydrogel system as a hard skeleton, which not only maintained the biocompatibility of KGM, but also gave the hydrogel superior mechanical properties and solvent resistance. Implanting a colloidal array inside the above film, we obtained a new type of biomass based photonic crystal that is sensitive to a variety of physical and chemical stimulus, especially for methanol. This photonic crystal responds to methanol and methanol vapor, and has the ability to detect methanol in gasoline, which has a good application prospect.
Recent advances in the improvement of g-C3N4 based photocatalytic materials
Yupeng Xing , Xiaoke Wang , Shuhua Hao , Xueli Zhang , Xiao Wang , Wenxuan Ma , Gang Zhao , Xijin Xu
2021, 32(1): 13-20  doi: 10.1016/j.cclet.2020.11.011
[Abstract](296) [FullText HTML] [PDF 1206KB](4)
g-C3N4 have been widely used in the fields of photocatalytic hydrogen production, photocatalytic degradation of dyes and oxidative degradation of toxic gases due to their excellent performance. It has attracted extensive attention in recent years due to its highly efficient photocatalytic capacity of hydrogen generation, water oxidation, carbon dioxide reduction and degradation of organic pollutants. Because of the abundant carbon and nitrogen composition of the earth, large-scale production and industrial applications of this material are possible. The modification of this material makes its performance more excellent so that this new material can obtain a steady stream of vitality. These outstanding works have become important materials and milestones on the road to mankind's photocatalytic hydrogen production. This review will begin with the basic idea of designing, synthesizing and improving g-C3N4 based photocatalytic materials, and introduce the latest development of g-C3N4 photocatalysts in hydrogen production from four aspects of controlling the carbon/nitrogen ratio, morphology, element doping and heterojunction structure of g-C3N4 materials.
Recent advances in the development of colorimetric analysis and testing based on aggregation-induced nanozymes
Honghong Rao , Xin Xue , Mingyue Luo , Haixia Liu , Zhonghua Xue
2021, 32(1): 25-32  doi: 10.1016/j.cclet.2020.09.017
[Abstract](261) [FullText HTML] [PDF 1047KB](7)
Colorimetric sensing strategies as a powerful point-of-care testing (POCT) tool have attracted significant interest in various chem/biosensing applications. Taking the excellent bare-eye-detectable signaling feature, nanozymes-based colorimetric sensors enable more potential applications and have been a new forefront in the colorimetric POCT analysis toward different target analytes. However, the low catalytic activity of nanozymes in most cases limits their practical application. Recent efforts demonstrate that the aggregation-induced nanozymes provide a general means to modulate nanozymes activity and enhance colorimetric sensing performances of some nanozymes-based colorimetric sensors. But there are few reports are explored to discuss and review such aggregation-induced nanozymes and their colorimetric sensing applications. To highlight the advances and progress in aggregation-induced nanozymes based colorimetric assays, we herein summary the fundamentals, classify and applications of this newly-developing field, focusing on the aggregation-induced activity enhancement of nanozymes (AIAE-nanozymes) with a significant "signal-on" feature and aggregation-induced activity inhibition of nanozymes (AIAI-nanozymes) with a dramatical "signal-off" characteristics. Finally, we also propose the current challenges and the future prospects on both AIAE-nanozymes and AIAI-nanozymes.
Discussion of the protein characterization techniques used in the identification of membrane protein targets corresponding to tumor cell aptamers
Zhukang Guo , Yuan Liu , Nongyue He , Yan Deng , Lian Jin
2021, 32(1): 40-47  doi: 10.1016/j.cclet.2020.11.061
[Abstract](227) [FullText HTML] [PDF 1085KB](1)
Aptamer is an oligonucleotide chain with specific binding ability to protein and other targets, which is widely used in many fields. Because of its ability to screen the premise of unknown targets, it can be used to discover some novel tumor markers, i.e., membrane proteins that are specifically highly expressed on the surface of tumor cells. Tumor markers can be used in many fields such as early diagnosis and treatment, and a new type of tumor marker proved to be effective can significantly improve the therapeutic effect of such tumors. However, further characterization of newly acquired membrane proteins is essential for their clinical use as tumor markers. This review first briefly introduced the process of obtaining novel tumor markers from nucleic acid aptamers. Next, the commonly used protein characterization methods could be used as a technical means to identify membrane protein targets corresponding to tumor cell aptamers, to clarify the principles, advantages and disadvantages of various means, and to analyze the most suitable situations for various experimental methods. Finally, the outlook was made and the characterization methods that should be used in such experiments were summarized.
Nanotechnology for diagnosis and therapy of rheumatoid arthritis: Evolution towards theranostic approaches
Junkai Zhao , Xuan Chen , Kwun-Hei Ho , Chao Cai , Cheuk-Wing Li , Mo Yang , Changqing Yi
2021, 32(1): 66-86  doi: 10.1016/j.cclet.2020.11.048
[Abstract](351) [FullText HTML] [PDF 2380KB](3)
Rheumatoid arthritis (RA), as a chronic autoimmune disease, damages the bone and cartilage of patients, and even leads to disability. Therefore, the diagnosis and treatment of RA is particularly important. However, due to the complexity of RA, it is difficult to make effective early diagnosis of RA, which is detrimental to RA treatment. Besides, long-term intake of anti-RA drugs can also cause damage to patients' organs. The emergence of nanotechnology provides the new train of thoughts for the diagnosis and treatment of RA. And the combination of diagnosis and therapy is an ideal method to solve the problem of disease management of RA patients. In this review, we summarize the mechanism and microenvironment of RA, discuss the commonly used diagnostic techniques and therapeutic drugs for RA, and review their advantages and disadvantages. New nanotherapy strategies such as drug-carrying nanoparticles, PTT, PDT are listed, and their applications in RA treatment are also summarized. In addition, multimodal imaging, combined therapy and responsive diagnosis and treatment are also summarized as important contents. At last, we also review typical nanocarriers that can be used in the integration of diagnosis and therapy, and discussed their potential applications in RA theranostics.
Recent advances in the development of activatable multifunctional probes for in vivo imaging of caspase-3
Pengzhan Wang , Huocheng Yang , Chang Liu , Mingqiang Qiu , Xin Ma , Zhiqiang Mao , Yao Sun , Zhihong Liu
2021, 32(1): 168-178  doi: 10.1016/j.cclet.2020.11.056
[Abstract](275) [FullText HTML] [PDF 1419KB](8)
Caspases are a family of proteases that play critical roles in controlling inflammation and cell death. Apoptosis is a caspase-3 mainly controlled behavior to avoid inflammation and damage to surrounding cells, whereas anomalistic cell apoptosis may be associated with many diseases. The detection and imaging of caspase-3 will be of great significance in evaluating the early therapeutic effect of tumors. Developing smart fluorescent probes may be helpful for the visualization of therapeutic effect compared with palways onq probes. Thus, more and more works toward activatable fluorescent probes for caspase-3 imaging have been reported. In addition, multifunctional probes have also been designed to further improve the imaging of caspase-3. Herein, this review systematically summarized the representative work of caspase-3 from the perspective of molecular design that it will play a guiding role in the design of probes that respond to caspase-3. Also, challenges and perspectives toward the field for imaging of cell apoptosis (caspase-3) are also discussed.
Sensing nanomaterials of wearable glucose sensors
Guanglei Li , Dan Wen
2021, 32(1): 221-228  doi: 10.1016/j.cclet.2020.10.028
[Abstract](221) [FullText HTML] [PDF 1126KB](5)
The metabolic disorder of glucose in human body will cause diseases such as diabetes and hyperglycemia. Hence the determination of glucose content is very important in clinic diagnosing. In recent years, researchers have proposed various non-invasive wearable sensors for rapid and real-time glucose monitoring from human body fluids. Unlike those reviews which discussed performances, detection environments or substrates of the wearable glucose sensor, this review focuses on the sensing nanomaterials since they are the key elements of most wearable glucose sensors. The sensing nanomaterials such as carbon, metals, and conductive polymers are summarized in detail. And also the structural characteristics of different sensing nanomaterials and the corresponding wearable glucose sensors are highlighted. Finally, we prospect the future development requirements of sensing nanomaterials for wearable glucose sensors. This review would give some insights to the further development of wearable glucose sensors and the modern medical treatment.
An overview of polymeric nanomicelles in clinical trials and on the market
Xue Zheng , Jizhen Xie , Xing Zhang , Weiting Sun , Heyang Zhao , Yantuan Li , Cheng Wang
2021, 32(1): 243-257  doi: 10.1016/j.cclet.2020.11.029
[Abstract](387) [FullText HTML] [PDF 1290KB](12)
Polymeric nanomedicine is a promising and rapidly evolving field. Among the different polymeric carriers, polymeric micelle (PM) with nanoscale size exhibit potent physical and biological advantages including excellent solubility and pharmacokinetics, enhanced efficacy and lower toxicity. PM has garnered increasing interest in research and in the clinic. This review will highlight the clinical outcomes of several PM-based formulations, and further summarized their preparation methods, strengths and challenges.
Transition metal carbides in electrocatalytic oxygen evolution reaction
Huaping Wang , Sheng Zhu , Jiwei Deng , Wenchao Zhang , Yuezhan Feng , Jianmin Ma
2021, 32(1): 291-298  doi: 10.1016/j.cclet.2020.02.018
[Abstract](241) [FullText HTML] [PDF 1541KB](4)
Oxygen evolution reaction (OER) is admitted to an important half reaction in water splitting for sustainable hydrogen production. The sluggish four-electron process is known to be the bottleneck for enhancing the efficiency of OER. In this regard, tremendous efforts have been devoted to developing effective catalysts for OER. In addition to Ir- or Ru-based oxides taken as the benchmark, transition metal carbides have attracted ever-increasing interest due to the high activity and stability as low-cost OER electrocatalysts. In this review, the transition metal carbides for water oxidation electrocatalysis concerning design strategies and synthesis are briefly summarized. Some typical applications for various carbides are also highlighted. Besides, the development trends and outlook are also discussed.
A leap forward in sulfonium salt and sulfur ylide chemistry
Rong Fan , Chen Tan , Yongguo Liu , Yun Wei , Xiaowen Zhao , Xinyuan Liu , Jiajing Tan , Hiroto Yoshida
2021, 32(1): 299-312  doi: 10.1016/j.cclet.2020.06.003
[Abstract](437) [FullText HTML] [PDF 2100KB](24)
Sulfonium salts and sulfur ylides are important S(Ⅳ) motifs, and have displayed many unique reactivities to provide simple, effective, and often stereoselective synthesis toward sulfur containing compounds. Impressive developments have been witnessed within this field during the past several years. In light of the increasing demand of organosulfur compounds across the range of chemical sciences, our aim of this review is to provide a concise overview of recent advances of sulfonium salt and sulfur ylide chemistry. Selected examples are organized in three parts on the basis of their role in organic reactions (reactants, intermediates and catalysts).
Supramolecular nano drug delivery systems mediated via host-guest chemistry of cucurbit[n]uril (n = 6 and 7)
Shengke Li , Yan Gao , Yuanfu Ding , Anni Xu , Huaping Tan
2021, 32(1): 313-318  doi: 10.1016/j.cclet.2020.04.049
[Abstract](216) [FullText HTML] [PDF 885KB](4)
As a novel family of macrocyclic molecules, cucurbit[n]urils (CB[n]s) have emerged as promising building blocks of supramolecular nano drug delivery systems (SNDDS) in recent years. Direct encapsulation of amphiphilic guests by CB[6] and CB[7] can modulate their amphiphilicity, resulting in formation of supramolecular amphiphiles that self-assemble into supramolecular nanoparticles for drug delivery. Additionally, CB[n]'s host-guest chemistry on the surface of mesoporous nanoparticles makes CB[n] an ideal blocking agent to control drug release from delivery vehicles. These SNDDS possess intrinsic stimuli responsiveness towards external guest or host, which can further incorporate responsiveness to a variety of other stimuli including pH, thermal, redox, photo and enzyme, to realize multiple stimuli-responsive drug release. Moreover, the recent breakthrough in direct functionalization of CB[n]s has provided a feasible method for preparing superior CB[6] and CB[7] derivatives that can be employed to build multifunctional SNDDS with unoccupied macrocycles located on surface, which could be decorated with various functional "tags" through host-guest chemistry. In this review, we summarized the recent progress of CB[6] and CB[7] based SNDDS through formation of supramolecular amphiphiles, supramolecular nanovalves as well as supramolecularly tailorable surface, which we hope to further promote the development of CB[n]s family as building blocks for advanced SNDDS.
Recent advances in theoretical studies on ligand-controlled selectivity of nickel- and palladium-catalyzed cross-coupling reactions
Mengna Cao , Hujun Xie
2021, 32(1): 319-327  doi: 10.1016/j.cclet.2020.04.005
[Abstract](436) [FullText HTML] [PDF 1082KB](1)
Nickel- and palladium-catalyzed cross-coupling reactions have attracted wide attentions, while ligandcontrolled selectivity in these reactions are still elusive, and calculations can help obtain possible catalytic cycles to generate different products and provide insights into key factors of selectivity, which facilitates the development of new catalyst systems to control reaction selectivity. This review covers our efforts and some significant achievements from other groups on ligand-controlled reaction selectivity of coupling reactions, including introduction, computational methods, selectivity control by ligands in Ni- and Pd-catalyzed coupling reactions, as well as summary and future perspectives.
Recent advance in synthesis and application of heteroatom zeolites
Tingting Pang , Xuanyu Yang , Chenyi Yuan , Ahmed A. Elzatahry , Abdulaziz Alghamdi , Xing He , Xiaowei Cheng , Yonghui Deng
2021, 32(1): 328-338  doi: 10.1016/j.cclet.2020.04.018
[Abstract](235) [FullText HTML] [PDF 931KB](3)
Incorporation of heteroatoms into the framework of zeolites has become a significant strategy to improve their performance in catalysis and adsorption, because the obtained heteroatom zeolites exhibit quite different properties from the conventional aluminosilicate zeolites in aspects of surface acidity, pore structures, particle size and so on. In this review, the progress on the heteroatom zeolites including their synthesis and application is highlighted. First, the recent advance on the design and synthesis of different heteroatom zeolites is summarized. Special emphasis is placed on the introduction and comparison of three typical methods, including the direct synthesis, post synthesis and improved direct synthesis, for the traditional heteroatom zeolites (such as TS-1, Sn-MFI, Sn-β) and newly-reported heteroatom zeolites (such as W-MFI, Mo-MFI). According to their intrinsic characteristics, the application of heteroatom zeolites in diverse fields, such as production of fine chemicals, air pollution control and biomass conversion is then discussed. Finally, the challenges and perspective on the future development of heteroatom zeolites in low-cost preparation and practical application are proposed.
Atomic defects, functional groups and properties in Mxenes
Wenjun Cui , Zhi-Yi Hu , Raymond R. Unocic , Gustaaf Van Tendeloo , Xiahan Sang
2021, 32(1): 339-344  doi: 10.1016/j.cclet.2020.04.024
[Abstract](281) [FullText HTML] [PDF 1134KB](6)
MXenes, a new family of functional two-dimensional (2D) materials, have shown great potential for an extensive variety of applications within the last decade. Atomic defects and functional groups in MXenes are known to have a tremendous influence on the functional properties. In this review, we focus on recent progress in the characterization of atomic defects and functional group chemistry in MXenes, and how to control them to directly influence various properties (e.g., electron transport, Li+ adsorption, hydrogen evolution reaction (HER) activity, and magnetism) of 2D MXenes materials. Dynamic structural transformations such as oxidation and growth induced by atomic defects in MXenes are also discussed. The review thus provides perspectives on property optimization through atomic defect engineering, and bottom-up synthesis methods based on defect-assisted homoepitaxial growth of MXenes.
The phototherapy toward corneal neovascularization elimination: An efficient, selective and safe strategy
Jingwen Yu , Chengchao Chu , Yiming Wu , Gang Liu , Wei Li
2021, 32(1): 99-101  doi: 10.1016/j.cclet.2020.11.025
[Abstract](168) [FullText HTML] [PDF 642KB](1)
Corneal neovascularization (CNV) can induce severe visual impairment and even blindness. Current treatments have limited efficacy and some undesirable side effects. Phototherapy (PT) is a modern medical technique in CNV treatment and worth further improvement. Nanotechnology has various advantages and nanoparticle-mediated drug delivery also contributes to CNV elimination. Phototherapy combined with functional nanoparticles featuring photoacoustic imaging contrast properties can accomplish accurate and safe inhibition of CNV, thus is promising in clinical application.
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