2014 Volume 25 Issue 10

Crystallization induced micellization of poly(p-dioxanone)-block-polyethylene glycol diblock copolymer functionalized with pyrene moiety
Chang-Lei Liu , Gang Wu , Si-Chong Chen , Jiao You , Yu-Zhong Wang
2014, 25(10): 1311-1317  doi: 10.1016/j.cclet.2014.07.009
[Abstract](223) [FullText HTML] [PDF 1601KB](0)
Abstract:
Poly(p-dioxanone)-block-polyethylene glycol diblock copolymers functionalized with pyrene moieties (Py-PPDO-b-PEG) at the chain ends of PPDO blocks were synthesized for preparing anisotropic micelles with improved stability. The micellization and crystallization of the copolymers were investigated by nano differential scanning calorimetry (Nano DSC), transmission electron microscopy (TEM), UV-vis spectrophotometery, fluorophotometer, and dynamic light scattering (DLS), respectively. The results indicated that the aggregation of pyrene induced by intermolecular interaction lead to micellization of Py-PPDO-b-PEG at much lower concentrations than those of PPDO-b-PEG copolymers without pyrene moieties. The aggregation of pyrene moieties may also serve as nucleation agent and therefore enhance the crystallization rate of PPDO blocks. Fluorescence measurements by using Nile Red as the fluorescent agent indicated that the micelles of Py-PPDO-b-PEG have high stability and load capacity for hydrophobic molecules.
A facile approach toward multicolor polymers:Supramolecular self-assembly via host-guest interaction
Xiao-Hai Yang , Fang Zhao , Lei-Liang He , Ke-Min Wang , Jin Huang , Qing Wang , Jian-Bo Liu , Meng Yang
2014, 25(10): 1318-1322  doi: 10.1016/j.cclet.2014.05.051
[Abstract](248) [FullText HTML] [PDF 875KB](0)
Abstract:
A one-step and facile strategy toward the construction of multicolor polymers via supramolecular selfassembly was proposed. Multicolor polymers were simply prepared by the self-assembly of adamantane-labeled fluorescein, adamantane-labeled rhodamine B and β-cyclodextrin polymers via host-guest interaction between β-cyclodextrin and adamantane. Multicolor polymers showed several interesting properties: multiple emission signatures by a single wavelength excitation, easy tunability, intense fluorescence, high photostablility. In addition, the self-assembly approach implied a facile and flexible strategy for constructing functionalized materials, such as multicolor materials for biological labeling and imaging, and sensing materials for the detection of physiological parameters.
Activation free energy of Zn(Ⅱ), Co(Ⅱ) binding to metallo-β-lactamase ImiS
Xia Yang , Ya-Jun Zhou , Pei He , Yun-Hua Guo , Cong-Jun Liu , Ke-Wu Yang
2014, 25(10): 1323-1326  doi: 10.1016/j.cclet.2014.06.024
[Abstract](287) [FullText HTML] [PDF 715KB](0)
Abstract:
In an effort to understand the recombination of a B2 metallo-β-lactamase (MβL), the binding of metals to apo-ImiS was studied by isothermal titration calorimetry and fluorescence spectra. The binding of Zn(Ⅱ), Co(Ⅱ) to apo-ImiS resulted in activation free energies ΔG6 values of 93.719 and 92.948 kJ mol-1, respectively, and increasing of fluorescence intensity at maxima emission of 340 nm.
Nucleophilic imidoesterification of dicarbonyl compounds with cyanatobenzenes through C-C bond formation
Hang Ma , Yang He , Ruo-Feng Huang , Xiao-Hui Zhang , Jing Pan , Jia-Qiang Li , Chao He , Xue-Ge Ling , Xuan-Lun Wang , Yan Xiong
2014, 25(10): 1327-1330  doi: 10.1016/j.cclet.2014.06.008
[Abstract](235) [FullText HTML] [PDF 479KB](0)
Abstract:
Under neat conditions, an efficient method for synthesis of imidoesters has been developed using cyanatobenzenes and dicarbonyl compounds. Nucleophilic addition spontaneously occurred between the two kinds of materials at room temperature with yields of up to 90%. A mechanism directed towards to the imidoester formation has been proposed.
A quick and effective multivariate statistical strategy for imaging mass spectrometry
Fei Tang , Yi Chen , Tie-Gang Li , Jiu-Ming He , Zeper Abliz , Gang Huang , Xiao-Hao Wang
2014, 25(10): 1331-1335  doi: 10.1016/j.cclet.2014.04.028
[Abstract](229) [FullText HTML] [PDF 1280KB](0)
Abstract:
A new multivariate statistical strategy for analyzing large datasets that are produced by imaging mass spectrometry (IMS) techniques is reported. The strategy divides the whole datacube of the sample into several subsets and analyses them one by one to obtain the results. Instead of analyzing the whole datacube at one time, the strategy makes the analysis easier and decreases the computation time greatly. In this report, the IMS data are produced by the air flow-assisted ionization IMS (AFAI-IMS). The strategy can be used in combination with most multivariate statistical analysis methods. In this paper, the strategy was combined with the principal component analysis (PCA) and partial least square analysis (PLS). It was proven to be effective by analyzing the handwriting sample. By using the strategy, the m/z corresponding to the specific lipids in rat brain tissue were distinguished successfully. Moreover the analysis time grew linearly instead of exponentially as the size of sample increased. The strategy developed in this study has enormous potential for searching for the m/z of potential biomarkers quickly and effectively.
A new green approach for the synthesis of 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthene-11-one derivatives using task specific acidic ionic liquid [NMP]H2PO4
Harjinder Singh , Sudesh Kumari , Jitender M. Khurana
2014, 25(10): 1336-1340  doi: 10.1016/j.cclet.2014.05.014
[Abstract](242) [FullText HTML] [PDF 408KB](0)
Abstract:
12-Aryl-8,9,10,12-tetrahydrobenzo[a]xanthene-11-one derivatives were synthesized by a convenient and environmentally benign procedure involving multicomponent condensation reactions of substituted aromatic aldehydes with 2,7-dihydroxynaphthalene/2-naphthols/2,6-dihydroxynaphthlene and cyclic 1,3-dicarbonyl compounds in task specific acidic ionic liquid [NMP]H2PO4 at 80℃. This protocol has proved to be efficient in terms of good yields, operational simplicity, easy workup, recyclability of reaction medium/catalyst, and short reaction time.
L-ProT catalyzed highly regioselective N-alkoxyalkylation of purine rings with vinyl ethers
Jian-Jun Li , Xing-Xing Gui
2014, 25(10): 1341-1345  doi: 10.1016/j.cclet.2014.04.023
[Abstract](350) [FullText HTML] [PDF 1002KB](0)
Abstract:
An efficient and regioselective synthesis of N-9 alkoxyalkylated purine nucleoside derivatives was achieved via the N-alkoxyalkylation of purine rings with vinyl ethers catalyzed by L-ProT. The advantages of this protocol include good to excellent yield, mild reaction condition, and simple manipulation. A plausible mechanism for the transformation was given.
Synthesis and thermal properties of novel calix[4]arene derivatives containing 1,2,3-triazole moiety via K2CO3-catalyzed 1,3-dipolar cycloaddition reaction
Zai-Gang Luo , Yu Zhao , Feng Xu , Chao Ma , Xue-Mei Xu , Xiao-Mei Zhang
2014, 25(10): 1346-1348  doi: 10.1016/j.cclet.2014.05.013
[Abstract](229) [FullText HTML] [PDF 342KB](0)
Abstract:
Two calix[4]arene derivatives containing 1,2,3-triazole moiety were synthesized via K2CO3-catalyzed 1,3-dipolar cycloaddition reaction between calix[4]arene-based azide and active methylene compounds in good yields. The structures of the two compounds synthesized herein were fully confirmed by 1H NMR, 13C NMR, and MS (ESI). The thermal analysis showed that the mass losses of the synthesized compounds 4 and 5 containing 1,2,3-triazole groups are similar to each other.
Improved synthesis of sterically encumbered multibrominated corroles
Mian HR Mahmood , Ze-Yu Liu , Hai-Yang Liu , Huai-Bo Zou , C. -K. Chang
2014, 25(10): 1349-1353  doi: 10.1016/j.cclet.2014.04.016
[Abstract](232) [FullText HTML] [PDF 579KB](0)
Abstract:
Efficient and easily reproducible synthesis of sterically hindered multibrominated corroles is achieved via dipyrromethane-aldehyde condensation reaction in good yields. Boron trifluoride dietherate (BF3·Et2O) is found to be the effective catalyst for cyclization reaction, giving corrole as the major product.
Iridoid glycosides from the roots of Scrophularia ningpoensis Hemsl
Ling-Juan Zhu , Cheng Qiao , Xiu-Yu Shen , Xue Zhang , Xin-Sheng Yao
2014, 25(10): 1354-1356  doi: 10.1016/j.cclet.2014.05.007
[Abstract](267) [FullText HTML] [PDF 308KB](0)
Abstract:
Two new iridoid glycosides, named scrophularianoids A (1) and B (2), were isolated from the roots of Scrophularia ningpoensis. The chemical structures were established on the basis of extensive analyses of spectroscopic data. Compounds 1 and 2 were inactive in our preliminary in vitro myocardial protective bioassay.
Efficient synthesis of chromenopyridine and chromene via MCRs
Hai-Feng Gan , Wei-Wei Cao , Zheng Fang , Xin Li , Shi-Gui Tang , Kai Guo
2014, 25(10): 1357-1362  doi: 10.1016/j.cclet.2014.05.008
[Abstract](275) [FullText HTML] [PDF 1095KB](0)
Abstract:
MCRs for preparation of chromenopyridines under reflux conditions and chromenes at room temperature conditions from different salicylaldehydes, malononitrile and different thiols (mol ratio = 1:2:1) were established. Mechanistic investigation suggests that the MCRs undergo different pathways at different temperatures and catalyzed by different organic bases. The structure of chromenopyridine and chromene are confirmed by crystal X-ray crystallography.
Preparation of single-handed helical phenolic resin nanofibers using a supramolecular templating method
Li-Qing Ma , Hao Chen , Yong-Min Guo , Bao-Zong Li , Yi Li
2014, 25(10): 1363-1366  doi: 10.1016/j.cclet.2014.05.035
[Abstract](227) [FullText HTML] [PDF 909KB](0)
Abstract:
Single-handed helical phenolic resin nanofibers were synthesized through a supramolecular templating approach using the supramolecular self-assemblies of a pair of chiral low-molecular-weight amphiphiles as the templates and 2,4-dihydroxybenzoic acid and formaldehyde as the precursors. The phenolic resin nanofibers were characterized using field-emission scanning electron microscopy, transmission electron microscopy and diffused reflection circular dichroism. The results indicated that the chirality of the supramolecular self-assemblies was successfully transferred to the phenolic resin nanofibers. The left-and right-handed helical phenolic resin nanofibers exhibited opposite optical activity.
Synthesis and thermal polymerization of perylene bisimide containing benzocyclobutene groups
Zhi-Jun Wei , Ye-Wei Xu , Lin Zhang , Mei-Ming Luo
2014, 25(10): 1367-1370  doi: 10.1016/j.cclet.2014.04.022
[Abstract](244) [FullText HTML] [PDF 504KB](0)
Abstract:
Fourfold benzocyclobutene-functionalized perylene bisimide (PBI 4) has been synthesized and its structure was characterized by FTIR, MS and NMR. PBI 4 can react either with itself, or the appropriate dienophiles to form the corresponding products under appropriate temperature. The polymer film obtained from the reaction of PBI 4 with methyl vinyl silicone rubber possessed excellent film forming properties including flatness. The optical properties of PBI 4 and polymer film obtained from the reaction of PBI 4 and methyl vinyl silicone rubber have been determined by UV/vis and fluorescence spectroscopy.
Imidazolium ionic liquid as the background ultraviolet absorption reagent for determination of morpholinium cations by high performance liquid chromatography-indirect ultraviolet detection
Hong Yu , Yi-Meng Sun , Chun-Miao Zou
2014, 25(10): 1371-1374  doi: 10.1016/j.cclet.2014.05.041
[Abstract](239) [FullText HTML] [PDF 365KB](0)
Abstract:
A novel analytical method was developed for determining morpholinium cations lacking ultraviolet absorption groups. This determination was carried out by high performance liquid chromatography-indirect ultraviolet (HPLC-IUV) detection using imidazolium ionic liquid as background absorption reagents, and imidazolium ionic liquid aq. soln.-organic solvent as mobile phase by a reversed-phase C18 column. The background ultraviolet absorption reagents, imidazolium ionic liquids and organic solvents were investigated. The imidazolium ionic liquid in the mobile phase is not only the background ultraviolet absorption reagent for IUV, but also an active component to improve the separation of morpholinium cations. It was found that morpholinium cations could be adequately determined when 0.5 mmol/L 1-ethyl-3-methylimidazolium tetrafluoroborate aq. soln./methanol (80:20, v/v) was used as mobile phase with an IUV detection wavelength of 210 nm. In this study, the baseline separation of Nmethyl, ethylmorpholinium cations (MEMo) and N-methyl, propylmorpholinium cations (MPMo) was successfully achieved in 8.5 min. The detection limits (S/N = 3) for MEMo and MPMo were 0.15 and 0.29 mg/L, respectively. This simple and practical method has been successfully applied to the determination of two morpholinium ionic liquids synthesized by the chemistry laboratory.
Interaction of benzene-1,3-disulfonylamid-kriptofix[22] with iodine in chloroform and dichloromethane solutions
Tayyebeh Madrakian , Sara Heidari
2014, 25(10): 1375-1378  doi: 10.1016/j.cclet.2014.04.015
[Abstract](222) [FullText HTML] [PDF 899KB](0)
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The interaction of iodine as an s-acceptor with a synthetic ligand, benzene-1,3-disulfonylamid-kriptofix [22] (BDSAK) as a p-donor has been investigated spectrophotometrically in chloroform (CHCl3) and dichloromethane (DCM) solutions. The results of mole ratio plots and Job's method show the stoichiometry of complexation I2/BDSAK is 1:1. Stability constants have been calculated in various temperatures and thermodynamic parameters have also been determined from the temperatures dependence of the stability constants by using van't Hoff equation. The results indicate the iodine complex with BDSAK is enthalpy stabilized but entropy destabilized.
Investigation of multilevel ion-pairing effect of triferrocenylmethane in organic phase
De-Bo Xiang , Hui-Bo Shao
2014, 25(10): 1379-1381  doi: 10.1016/j.cclet.2014.07.004
[Abstract](344) [FullText HTML] [PDF 508KB](0)
Abstract:
The intramolecular electronic communication and multilevel ion-pairing effect of triferrocenylmethane (TriFcM) in organic phase was studied with the ‘‘thin-layer electrochemistry'' approach. Three pairs of symmetric peaks in cyclic voltammetry of TriFcM correspond to three one-electron electrochemical reaction processes and indicate strong intramolecular electronic communication, which could be used to study the multilevel ion-pairing effect. Three different formation constants of ion-pairs between the three ferroceniums of TriFcM and perchlorate in thin organic film were obtained and compared.
Highly efficient and magnetically separable nano-CuFe2O4 catalyzed S-arylation of thiourea by aryl/heteroaryl halides
Abdol R. Hajipour , Morteza Karimzadeh , Ghobad Azizi
2014, 25(10): 1382-1386  doi: 10.1016/j.cclet.2014.05.015
[Abstract](258) [FullText HTML] [PDF 435KB](0)
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The non-toxic and magnetically separable nano-CuFe2O4 catalyzed synthesis of symmetrical aryl sulfides by the reaction of thiourea with a wide variety of aryl halides, including aryl chlorides has been reported. Excellent yields of products have been obtained under ligand-free conditions and without the use of any expensive catalyst, such as palladium.
One-pot synthesis of novel pyrido[2,3-d]pyrimidines using HAp-encapsulated-γ-Fe2O3 supported sulfonic acid nanocatalyst under solvent-free conditions
Moona Mohsenimehr , Manouchehr Mamaghani , Farhad Shirini , Mehdi Sheykhan , Fatemeh Azimian Moghaddam
2014, 25(10): 1387-1391  doi: 10.1016/j.cclet.2014.04.025
[Abstract](274) [FullText HTML] [PDF 1171KB](0)
Abstract:
Novel pyrido[2,3-d]pyrimidine derivatives were synthesized through a one-pot three-component approach using HAp-encapsulated-γ-Fe2O3 [γ-Fe2O3@HAp-SO3H] catalyzed condensation of 6-amino-2-(methylthio or ethylthio)pyrimidin-4(3H)-one, Meldrum's acid and aryl aldehydes at 60℃ and under solvent-free conditions. In this protocol the use of nanocatalyst provided a green, useful and rapid method to generate the products in short reaction times and excellent yields (88%-94%).
Determination of iminodiacetic acid in the glyphosate by ion chromatography
Jie He , Jia-Sheng Yu , Yan-Jie Hou , Zuo-Yi Zhu , Zhong-Ping Huang , Mu-Hua Wang , Nai-Fei Zhong , Yan Zhu
2014, 25(10): 1392-1394  doi: 10.1016/j.cclet.2014.05.036
[Abstract](228) [FullText HTML] [PDF 400KB](0)
Abstract:
In this paper, a simple method based on ion chromatography (IC) with conductivity detection was developed for the determination of iminodiacetic acid (IDA) in the herbicide of glyphosate. Under optimized chromatographic conditions, good linear relationship, sensitivity and reproducibility were obtained. The detection limit (LOD) for IDA obtained by injecting 25 μL of sample was 31.8 μg/L (S/ N = 3). Relative standard deviation (RSD) of repeated analysis for the peak areas was less than 1.53% (n = 6). A spiking study was performed with satisfactory recoveries between 92.8% and 103.6%. It was confirmed that this method could be applied in glyphosate products.
A catalyst-free novel synthesis of diethyl carbonate from ethyl carbamate in supercritical ethanol
Li-Cai Zhao , Zhi-Qiang Hou , Chun-Ze Liu , Yuan-Yuan Wang , Li-Yi Dai
2014, 25(10): 1395-1398  doi: 10.1016/j.cclet.2014.05.012
[Abstract](232) [FullText HTML] [PDF 606KB](0)
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Diethyl carbonate has been synthesized via the alcoholysis of ethyl carbamate in supercritical ethanol under catalyst-free conditions. The influences of various parameters such as reaction temperature, reaction time, reaction pressure, ethanol/ethyl molar ratios and reaction loading volume on the yield of DEC were studied systematically. The experimental results indicated that the alcoholysis of ethyl carbamate was greatly improved in supercritical ethanol. The optimal reaction conditions were as follows: a reaction temperature of 573 K, a reaction time of 30 min, a reaction pressure of 13.2 MPa, an ethanol/ethyl carbamate molar ratio of 10 and a reactor loading volume of 285 μL respectively. The optimal yield of DEC was 22.9%.
Fluorinated 1,8-naphthalimides:Synthesis, solid structure and properties
Jie Huang , Di Wu , Hao-Jie Ge , Sheng-Hua Liu , Jun Yin
2014, 25(10): 1399-1402  doi: 10.1016/j.cclet.2014.04.017
[Abstract](318) [FullText HTML] [PDF 581KB](0)
Abstract:
Three fluorinated 1,8-napthalimides were synthesized from acenaphthene. Their structures were characterized by NMR and EI-MS analyses. The structures of compounds 1b and 1c were also confirmed by X-ray diffraction analysis, which showed that they possessed different packing models. Their optoelectronic properties were investigated. The results indicated that all of the naphthalimides possess good solubility and low LUMO energy level, which make them good solution processing candidates in n-type semiconductor.
Tuning plasmon absorption of unmodified silver nanoplates for sensitive and selective detection of copper ions by introduction of ascorbate
Xiao-Dong Xia , Tian-Lun Wang , Xiao-Yuan Yuan
2014, 25(10): 1403-1406  doi: 10.1016/j.cclet.2014.05.033
[Abstract](249) [FullText HTML] [PDF 643KB](0)
Abstract:
Silver nanoplates as novel optical sensors for Cu2+ detection have been demonstrated. Silver nanoplates are synthesized via previous H2O2-NaBH4 cyclic oxidation-reduction reactions. With introduction of ascorbate as mild reductants, Cu2+ ions are reduced into Cu+ and the Cu+ is further reduced to Cu, which is deposited on the surface of the silver nanoplates. The deposition of the Cu on the surface of the silver nanoplates allows a significant red-shift of their plasmon absorption. Therefore, trace Cu2+ can be detected. The shift of the plasmon absorption wavelength of silver nanoplates is proportional to the Cu2+ concentration over a range of 40-340 μmol L-1 with a limit of detection of 9.0 μmol L-1. Moreover, such silver nanoplate-based optical sensors provide good selectivity for Cu2+ detection, and most other metal ions do not disturb its detection. Moreover, the practicality of the proposed sensor was tested. This Cu2+ assay is advantageous in its simplicity, selectivity, and cost-effectiveness.
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