2007 Volume 18 Issue 5

Copper-mediated synthesis of N, N'-diarylhydrazines from boronic acids
Ye Feng Wang , Yuan Zhou , Jia Rui Wang , Lei Liu , Qing Xiang Guo
2007, 18(5): 499-501  doi: 10.1016/j.cclet.2007.03.002
[Abstract](156) [FullText HTML] [PDF 214KB](0)
N, N'-Diarylhydrazines have been prepared via the reaction of N-Boc-aryl hydrazines with boronic acids mediated by copper acetate. This mild reaction condition tolerates the presence of a variety of functional groups.
A green synthesis of dihydropyrimidinones by Biginelli reaction over Nafion-H catalyst
Hai Xia Lin , Qing Jie Zhao , Bin Xu , Xiao Hong Wang
2007, 18(5): 502-504  doi: 10.1016/j.cclet.2007.03.022
[Abstract](150) [FullText HTML] [PDF 213KB](0)
A Nafion-H catalyzed, single step and environmentally friendly process for synthesis of dihydropyrimidinones is described. This adopted protocol for Biginelli reaction has the advantages of reusability of the catalyst, high yields and ease of separation of pure products.
Synthesis and electrochemical properties of 2, 6-bis(6-aryl-[1, 2, 4]-triazolo[3, 4-b] [1, 3, 4]-thiadiazole-3-yl)pyridines
Chun Xia Tan , Ruo Fei Feng , Xiao Xia Peng
2007, 18(5): 505-508  doi: 10.1016/j.cclet.2007.03.001
[Abstract](151) [FullText HTML] [PDF 294KB](0)
By the condensation of 2, 6-bis (4-amino-5-mercapto-[1, 2, 4]-triazoles-2) pyridine with aromatic acid in the presence of phosphorus oxychloride. Compounds of 2, 6-bis (6-aryl-[1, 2, 4]-triazolo[3, 4-b] [1, 3, 4]-thiadiazole-3-yl) pyridines were synthesized.Their structures were confirmed by IR, 1H NMR spectroscopies and elemental analysis. Their electrochemical behavior and cyclic voltammogram also were be studied. The results showed that they have high ionization potentials and good affinity.
Synthesis and photophysical properties of metal anthraquinone phthalocyanine
Yi Ru Peng , Kui Zhi Chen , Jia Bao Wen , Ji Cheng Shi , Bao Quan Huang
2007, 18(5): 509-512  doi: 10.1016/j.cclet.2007.03.004
[Abstract](150) [FullText HTML] [PDF 287KB](0)
A novel anthraquinone phthalocyanine Al (Ⅲ) 4 and Co (Ⅱ) 5 were synthesized and characterized by elemental analysis, IR, UV/vis, 1H NMR, HPLC and MS. The photophysical properties of the two metal complexes were studied and compared by fluorescence spectrum method.
Synthesis of a novel tri-antennary galactoside with high hepatocyte targeting
Lei Tang , Yong Wu , Jiao Lu , Zhi Rong Zhang , Jin Cheng Yang , Li Hai
2007, 18(5): 513-515  doi: 10.1016/j.cclet.2007.03.018
[Abstract](162) [FullText HTML] [PDF 239KB](0)
A novel bifunctional compound carrying cluster thiogalactoside as the cell targeting ligands was synthesized for gene delivery to hepatocytes. Tetra-antennary dendr-OMs45 was used as a scaffold for the attachment of three galactosides, while the other mesylate end was linked with cholesterol through poly (ethylene glycol) chain. This design provided an effective entry for the synthesis of the bifunctional compound.
Studies on the cyclization reaction of D-aspartic acid
Yu Chuan Li , Si Ping Pang , Yong Zhong Yu
2007, 18(5): 516-518  doi: 10.1016/j.cclet.2007.03.013
[Abstract](205) [FullText HTML] [PDF 240KB](0)
The cyclization reaction of D-aspartic acid was studied, the carboxyl groups of D-aspartic acid were protected by benzyl alcohol to give compound D-dibenzyl aspartate. Then (4R)-benzyl azetidine-2-one-4-carboxylate and meso-3, 6-disubstituted piperazine2, 5-diones were synthesized via intramolecular cyclization and intermolecular cyclization of D-dibenzyl aspartate, respectively, and their structures were confirmed by 1H NMR and MS. Both cyclization reaction conditions were also investigated in detail.
Synthesis and photoreaction mechanism of a novel bifunctional photochromic compound
Chang Rui Zhang , Wen Peng Yan , Mei Gong Fan
2007, 18(5): 519-522  doi: 10.1016/j.cclet.2007.03.019
[Abstract](154) [FullText HTML] [PDF 308KB](0)
New functionalized spiroxazine containing azo group has been prepared and its photochromic mechanism has been investigated by laser induced time-resolved techniques.
Synthesis and curing of a novel amino-containing phthalonitrile derivative
Ke Zeng , Ke Zhou , Wen Rui Tang , Yan Tang , Hong Fei Zhou , Tao Liu , Yi Peng Wang , Hai Bing Zhou , Gang Yang
2007, 18(5): 523-526  doi: 10.1016/j.cclet.2007.03.035
[Abstract](159) [FullText HTML] [PDF 307KB](0)
A novel phthalonitrile derivative containing an amino group, 3, 5-bis (3, 4-dicyanophenoxy) aniline (CPA), was synthesized via a nucleophilic displacement of 4-nitrophthalonitrile and 5-aminoresorcinol hydrochloride. The structure of CPA was confirmed by Fourier transform infrared spectra (FT-IR) and nuclear magnetic resonance (1H NMR). Thermal analysis performed on CPA revealed that the novel phthalonitrile derivative showed a self-promotion curing behavior and the resulting polymer exhibited outstanding heat-resistance.
Synthesis and mesomorphic properties of new azine-type liquid crystals
Qiang Wei , Lin Shi , Hui Cao , Huai Yang , Yan Bin Wang
2007, 18(5): 527-529  doi: 10.1016/j.cclet.2007.03.008
[Abstract](161) [FullText HTML] [PDF 808KB](0)
A series of symmetrical azine-type liquid crystals were synthesized. The characteristic of these liquid crystals is that they had high clearing point (~320℃) and broad thermal range of nematic phase (~154℃). It was also found that the end groups of the liquid crystals had effect on the mesomorphic properties.
Synthesis of a new 2, 2':6', 2"-terpyridine derivative and its coordination property
Yong Chen , Xi Juan Zhao , Jun Feng Zhang , Wen Fu Fu
2007, 18(5): 530-532  doi: 10.1016/j.cclet.2007.03.017
[Abstract](153) [FullText HTML] [PDF 265KB](0)
A novel compound, (E)-4'-(4-(but-1-en-3-ynyl) phenyl)-2, 2':6', 2"-terpyridine 1 was synthesized from 4'-(4-bromomethylphenyl)-2, 2':6', 2"-terpyridine phosphonium salt 2 and propargylaldehyde via Wittig reaction, and characterized by EI-MS and 1H NMR as well as elemental analysis. The spectral changes of the compound in the presence of transition metal ions, such as Cu (Ⅰ) or Zn (Ⅱ), are investigated.
H-Y-zeolites induced heterocyclization: Highly efficient synthesis of substituted-quinazolin-4(3H)ones under microwave irradiation
M. Bakavoli , O. Sabzevari , M. Rahimizadeh
2007, 18(5): 533-535  doi: 10.1016/j.cclet.2007.03.029
[Abstract](177) [FullText HTML] [PDF 195KB](0)
A highly efficient synthesis of 2-amino-N-substituted-benzamides was performed by the condensation of isatoic anhydride with several amines in solvent-free conditions under microwave irradiation. H-Y-zeolites induced heterocyclization of these products with ortho-esters under similar conditions afforded the relevant substituted-quinazolin-4(3H) ones in high yields.
A facile synthesis of 2, 3-dihydro-2-aryl-4(1H)-quinazolinones catalyzed by scandium(Ⅲ) triflate
Jiu Xi Chen , Hua Yue Wu , Wei Ke Su
2007, 18(5): 536-538  doi: 10.1016/j.cclet.2007.03.037
[Abstract](163) [FullText HTML] [PDF 193KB](0)
2, 3-Dihydro-2-aryl-4(1H)-quinazolinones were prepared in good yields via condensation of o-aminobenzamide with aldehydes promoted by a catalytic amount of Sc (Otf)3 under mild conditions.
Synthesis and NHE1 inhibitory activity of ligustrazine derivatives
Mei Ren , Yun Gen Xu , Na Wen , Da Yong Zhang , Wei Yi Hua
2007, 18(5): 539-541  doi: 10.1016/j.cclet.2007.03.020
[Abstract](152) [FullText HTML] [PDF 223KB](0)
A series of novel derivatives of ligustrazine linked with substituted benzoyl guanidine were synthesized. These compounds have not been reported in literature, and their chemical structures were confirmed by IR, 1H NMR and MS. The results of NHE1 inhibitory activity test showed that compounds 2, 3, 4, 6, and Ⅰ7 possess more potent NHEl inhibitory activity than cariporide.
Hydroxylation of 3-nitrotyrosine by hydroxyl radical
Jun Chen Dong , Wei Qun Shi , Yu Fen Zhao , Yan Mei Li
2007, 18(5): 542-544  doi: 10.1016/j.cclet.2007.03.032
[Abstract](168) [FullText HTML] [PDF 360KB](0)
Hydroxylation of 3-nitrotyrosine (3-NT) and 3-NT containing peptide Gly-nitroTyr-Gly in aqueous solution by hydroxyl radical were investigated with gamma irradiation. The structures of the hydroxylated products were confirmed by electrospray ionization mass spectrometry and 1H NMR spectrometry. The reactivity of 3-nitrotyrosine has been investigated using density functional theory (DFr) calculation.
Two new diterpene alkaloids from Delphinium chrysotrichum
Yang Qing He , Xiao Mei Wei , Yi Li Han , Li Ming Gao
2007, 18(5): 545-547  doi: 10.1016/j.cclet.2007.03.003
[Abstract](152) [FullText HTML] [PDF 200KB](0)
Chemical investigation on the ethanol extract from the whole plants of Delphinium chrysotrichum resulted in the isolation of two new diterpene alkaloids named delphatisine A (1) and delphatisine B (2), respectively. The structures of the new compounds were deduced on the basis of their spectral data (IR, HREIMS, EIMS, 1D, 2D-NMR). This is the first report on the isolation of diterpenoid alkaloids from the D. Chrysotrichum.
A novel phenylpropanoid glycosides and a new derivation of phenolic glycoside from Paris Polyphyllavar. yunnanensis
Yu Wang , Wen Yuan Gao , Tie Jun Zhang , Yuan Qiang Guo
2007, 18(5): 548-550  doi: 10.1016/j.cclet.2007.03.011
[Abstract](157) [FullText HTML] [PDF 246KB](0)
A novel phenylpropanoid glycosides 1, named parispolyside F, and a novel derivation of phenolic glycoside 2, named parispolyside G, as well as two known flavonoid glycosides were isolated from the rhizome of Paris polyphylla var. Yunnanensis.Their structures were elucidated by spectroscopic methods.
Two new phenolic compounds from Artemisia sphaerocephala
Dong Bao Zhao , Lin Xi Li , Xiu Hua Liu , Ming Jing Li , Wen Ling Wang
2007, 18(5): 551-553  doi: 10.1016/j.cclet.2007.03.033
[Abstract](160) [FullText HTML] [PDF 223KB](0)
Two new phenolic compounds were isolated from whole plant of Artemisia sphaerocephala. The structures were elucidated on the basis of spectroscopic methods as 4-(1-hydroxylethyl)-phenol-1-O-β-D-glucopyranoside and 4-O-acetophenone-β-D-glucopyranosyl-(1-3)-β-D-glucopyranoside.
Two new saponins from the aerial part of Astragalus membranaceusvar. mongholicus
Qing Tao Yu , Ping Li , Zhi Ming Bi , Jun Luo , Xiao Dan Gao
2007, 18(5): 554-556  doi: 10.1016/j.cclet.2007.03.025
[Abstract](153) [FullText HTML] [PDF 216KB](0)
Two new saponins named mongholicoside A (1) and mongholicoside B (2) were isolated from the aerial part of Astragalus membranaceus var. mongholicus. Their structures were determined by 1D and 2D NMR, ESI-MS techniques and chemical methods.
Site-specifically cleavage of oxidized insulin B chain with Zn(Ⅱ) ion studied by electrospray ionization mass spectrometry
Jiang Jiang , Yu Hua Mei , Long Gen Zhu , Wen Ji Wang
2007, 18(5): 557-560  doi: 10.1016/j.cclet.2007.03.016
[Abstract](141) [FullText HTML] [PDF 1027KB](0)
The electrospray ionization mass spectrometry and tandem mass spectrometry investigation showed that the binding sites of Zn2+ with oxidized insulin B chain are His 5, His 10, and Arg 22, which lead to the selective cleavages of the peptide bonds at Asn 3-Gln 4, His 5-Leu 6, Gly 8-Ser 9, and Glu 21-Arg 22 of oxidized insulin B chain.
Tris(2, 2'-bipyridyl)ruthenium(Ⅱ) electrochemiluminescence (ECL) enhanced by rutin on platinum electrode
Da Xu , Zhong Lan Gao , Na Li , Ke An Li
2007, 18(5): 561-564  doi: 10.1016/j.cclet.2007.03.010
[Abstract](166) [FullText HTML] [PDF 503KB](0)
Ru (bpy)32+ electrochemiluminescence (ECL) was applied to determination of rutin. ECL intensity of Ru (bpy)32+ could be enhanced in the presence of rutin in basic solution on platinum electrode. At pH 9.9, light emission intensity was found to be linear with rutin in the range of 1-50μmol/L.
Determination of selectivity of HPLC systems by correspondence factor analysis
Yuan Wang , Jun Yang , Xin Lu , Guo Wang Xu
2007, 18(5): 565-568  doi: 10.1016/j.cclet.2007.03.026
[Abstract](167) [FullText HTML] [PDF 355KB](0)
Correspondence factor analysis (CFA) was employed to study the selectivity of 14 HPLC systems, The tested LC systems were classified as reversed-phase (RP), ion-exchange (IE) and hydrophilic interaction chromatography (HILIC) modes. It was found that the retentions of the hydrophilic solutes on HILIC column were significantly influenced by the second-order effects besides their hydrophilic properties. Organic modifiers and residue silanol groups on silica surface both participated in retention. HypersilTM amino column performed separation in the HILIC mode at appropriate conditions, and its retention mechanism was more similar to that of HILIC silica column than that of HILIC column coating poly (aspartamide) groups.
Investigation of the interaction of DNA and neutral red by fluorescence spectroscopic analysis
Yong Nian Ni , Xue Zhi Zhong
2007, 18(5): 569-572  doi: 10.1016/j.cclet.2007.03.027
[Abstract](162) [FullText HTML] [PDF 971KB](0)
The binding characteristics of neutral red (NR) with DNA were investigated by fluorescence spectrometry. Chemometrics approach as singular value decomposition (SVD) was used to evaluate the number of spectral species in the drug-DNA binding process, and then the intrinsic binding constant of 1.6×104 in base pairs and the binding site number of 0.97 were obtained from the Scatchard plot.
A novel terbium complex using oxadiazole derivative as a neutral ligand: Synthesis and properties
Yu Liu , Kong Qiang Xing , Ji Yong Deng , Mei Xiang Zhu , Xia Yu Wang , Wei Guo Zhu
2007, 18(5): 573-576  doi: 10.1016/j.cclet.2007.03.028
[Abstract](158) [FullText HTML] [PDF 237KB](0)
A novel terbium complex using 1, 3, 4-oxadiazole derivative as a neutral ligand was synthesized and characterized. Its thermal stability and photoluminescent properties were studied. The strong emission peaked at 546 nm with a full width at half maximum of 5 nm was observed in the pure terbium complex film under excitation of 328 nm light, which is attributed to the characteristic emission of terbium ion. The good thermal stability and intense sharp emission of this terbium complex display its potential application in electroluminescence devices.
Growing kinetics and structural characterization of oxide film formed on La-doped Co-40Cr alloy
Hui Ming Jin , Adriana Felix , Majorri Aroyave
2007, 18(5): 577-580  doi: 10.1016/j.cclet.2007.02.016
[Abstract](145) [FullText HTML] [PDF 1413KB](0)
The isothermal and cyclic oxidizing kinetics of Co-40Cr alloy and its lanthanum ion-implanted samples were studied at 1000℃ in air by thermal-gravity analysis (TGA). Scanning electronic microscopy (SEM) and transmission electronic microscopy (TEM)) were used to examine the oxidized film's morphology and the structure after oxidation. Secondary ion mass spectrum (SIMS) method was used to examine the binding energy change of chromium caused by La-doping and its influence on formation of Cr2O3 film. Laser Raman spectrum was used to examine the tress changes within oxidized films. It was found that lanthanum implantation remarkably reduced the isothermal oxidizing rate of Co-40Cr and improved the anti-cracking and anti-spalling properties of Cr2O3 film. The reasons were that the implanted lanthanum reduced the grain size and internal stress of Cr2O3 oxide, increased the high temperature plasticity of oxidized film. Lanthanum mainly existed in the outer surface of Cr2O3 film in the forms of fine La2O3 and LaCrO3 spinel particles.
Chemically binding Eu3+ onto CdS semiconductor nanoparticle surface
Guang Hua Zhu , Krystyna Tomsia , Hong Yu , Motlan , Ewa M. Goldys
2007, 18(5): 581-584  doi: 10.1016/j.cclet.2007.03.034
[Abstract](156) [FullText HTML] [PDF 733KB](0)
Europium ions were chemically bound to CdS nanoparticles surface by diethylenetri-aminepentaacetate (DTPA, 1) in a two-step synthetic route. First 1 was applied to chelate with cadmium on the surface of cadmium-rich CdS nanoparticles and act as a capping agent. Further, the purified 1-capped particles were used to bind with Eu3+. The purified and redispersed particles were characterized by photoluminescence spectroscopy, TEM and SEM. It was observed that Eu3+ on the nanoparticle surface significantly increased the band gap emission and decreased the surface emission intensity of the CdS nanoparticles.
The effects of Te on the performance of Mo-V catalysts prepared by hydrothermal synthesis
Hua Chang Jiang , Ling Zeng , Bin Long Yin
2007, 18(5): 585-587  doi: 10.1016/j.cclet.2007.03.006
[Abstract](153) [FullText HTML] [PDF 204KB](0)
Some Mo-V-Te-La catalysts with varied component were prepared by hydrothermal synthesis and dried with microwave method. The component of the catalyst were greatly affected the crystal structure and Raman spectrum. The phase in the catalysts was different when the Mo, V, and Te content varied. When the catalyst containing the same Mo, V content, due to the effect of dopant of Te element (V0.07Mo0.93)5O14 became the main phase in the catalyst. The catalyst also showed good activity for the reaction of selective oxidation propane to acrolein and acrylic acid.
A fibrous hypercrosslinked sorbent prepared on PP-ST-DVB matrix viapost-crosslinking reaction
Feng Liu , Si Guo Yuan , Xiao Li Wang , A. P. Polikarpov , A. A. Shunkevich
2007, 18(5): 588-590  doi: 10.1016/j.cclet.2007.03.036
[Abstract](156) [FullText HTML] [PDF 1025KB](0)
A fibrous sorbent possessing abundant micropore structure was firstly prepared via post-crosslinking reaction on the PP-ST-DVB original fiber. Its micromorphology and sorptive properties were investigated, and the results. Demonstrated that the novel fibrous hypercrosslinked sorbent has narrow pore-size distribution, small average porous radius (1.90 nm), high specific surface area (362.31 m2/g), and fine sorptive properties for small organic molecules.
Characterization of silylated Ti-grafted HMS catalyst and its excellent epoxidation performance
Xue Feng Li , Huan Xin Gao , Guo Jie Jin , Lin Ding , Lu Chen , Hong Yun Yang , Xin He , Qing Ling Chen
2007, 18(5): 591-594  doi: 10.1016/j.cclet.2007.03.021
[Abstract](154) [FullText HTML] [PDF 259KB](0)
Silylated Ti-grafted hexagonal mesoporous silica (HMS) catalyst was prepared by the chemical vapor deposition (CVD) using TiCl4 as titanium source and hexamethyldisilazane (HMDSZ) as silylating agent. The samples were characterized by XRD, N2-adsorption, FTIR, 29Si NMR, DR UV-vis, and evaluated by epoxidation of styrene, propylene, cyclohexene, and 1-hexene with cumene hydroperoxide (CHP) as oxidant, respectively. It is revealed that the catalyst possesses typical mesoporous structure, high hydrophobicity and highly dispersed tetracoordinated titanium sites and hence exhibits excellent performance in epoxidation of olefins.
Synthesis and characterization of new soluble poly(aryl ether nitrile)s containing phthalazinone moiety
Ming Jing Wang , Cheng Liu , Li Ming Dong , Xi Gao Jian
2007, 18(5): 595-597  doi: 10.1016/j.cclet.2007.03.030
[Abstract](150) [FullText HTML] [PDF 256KB](0)
A series of novel poly (aryl ether nitrile) s containing phthalazinone moiety were synthesized by the nucleophilic displacement reaction of bisphenol-like monomers (Ⅰ) with 2, 6-difluorobenzonitrile. The inherent viscosities ranged from 0.46 to 1.07 dL g-1.The glass transition temperatures were in the range of 277-295℃, and the temperatures for 10% weight loss in nitrogen atmosphere were found between 495 and 527℃. The structures of these resultant polymers were confirmed by FT-IR and 1H NMR. Moreover, the properties of poly (aryl ether nitrile) s including solubility and crystallinity were also studied.
A novel epoxy methacrylate resin containing phthalazinone moiety for UV coatings
Yan Kou , Jin Yan Wang , Xi Gao Jian
2007, 18(5): 598-600  doi: 10.1016/j.cclet.2007.03.024
[Abstract](151) [FullText HTML] [PDF 220KB](0)
A novel phthalazinone modified epoxy acrylate resin for the high temperature resistant ultravioet (UV) curable coating was synthesized. The methacrylated epoxy resins obtained were utilized to UV radiation curing by taking 2.5% (wt%) of photoinitiator in combination with 20% (wt%) of diluent, and generated the interpenetraring polymer networks. The cured film had good thermal and chemical stability.
Novel ionic liquids as reaction medium for atom transfer radical polymerization of methyl methacrylate
Guo Qiao Lai , Fu Min Ma , Zi Qiang Hu , Hua Yu Qiu , Jian Xiong Jiang , Ji Rong Wu , Li Min Chen , Lian Bin Wu
2007, 18(5): 601-604  doi: 10.1016/j.cclet.2007.03.014
[Abstract](144) [FullText HTML] [PDF 244KB](0)
Atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) employing ethyl 2-bromoisobutyrate (EBiB)/CuBr as the initiating system was investigated at 50℃ in the absence of any additional ligand in the three room temperature ionic liquids (RTILs), 1-methyl-imidazolium acetate ([mim] [CH3COO]), 1-methylimidazolium propionate ([mim] [CH3CH2COO]) and 1-methylimidazolium butyrate ([mim] [CH3CH2CH2COO]), respectively. All the polymerization in the three RTILs proceeded in a well-controlled manner. The sequence of the apparent polymerization rate constants was kapp([mim] [CH3COO]) >kapp([mim] [CH3CH2COO]) >kapp([mim] [CH3CH2CH2COO]).
Synthesis and characterization of biodegradable polymer: Poly (ethene maleic acid ester-co-D, L-lactide acid)
Mei Na Huang , Yan Feng Luo , Jia Chen , Yong Gang Li , Chun Hua Fu , Yuan Liang Wang
2007, 18(5): 605-608  doi: 10.1016/j.cclet.2007.03.007
[Abstract](151) [FullText HTML] [PDF 333KB](0)
A novel biodegradable polymer-poly (ethene maleic acid ester-co-D, L-lactide acid) was synthesized by copolymerizing lactide and prepolymer, which was prepared by the condensation of maleic anhydride and glycol, using p-toluene sulphonic acid as a catalyst, attempting to improve the hydrophilicity, increase flexibility and modulate the degradation rate. FTIR, 1H NMR, MALLS and DSC were employed to characterize these polymers.
Studies on synthesis and property of novel acid-base proton exchange membranes
Yong Fang Liang , Hai Yan Pan , Xiu Ling Zhu , Yao Xia Zhang , Xi Gao Jian
2007, 18(5): 609-612  doi: 10.1016/j.cclet.2007.03.031
[Abstract](139) [FullText HTML] [PDF 251KB](0)
Sulfonated poly (phthalazinone) s (SPPENK, SPPESK and SPPBEK) were prepared by direct polymerization reaction from sulfonated monomers. The novel acid-base membranes were composed of sulfonated polymers as the acidic compounds, and polyetherimide (PEI) as the basic compounds, casting from their N-methylpyrrolidone (NMP) solution directly onto clean glass plates at 60℃ aiming at enhancing membrane toughness and other relative properties. The resulted acid-base composite membranes had excellent resistance to swelling, thermo-stability, hydrolysis resistance and oxidative resistance properties with highly ion-exchange capacity (IEC).
Synthesis and characterization of biodegradable materials: PDLLA-(MAh-Diol)n-PDLLA copolymer
Jia Chen , Yuan Liang Wang , Mei Na Huang
2007, 18(5): 613-616  doi: 10.1016/j.cclet.2007.03.015
[Abstract](159) [FullText HTML] [PDF 227KB](0)
The novel biodegradable copolymer PDLLA-(MAH-Diol)n-PDLLA with unsaturated bond was synthesized by copolymerizing lactide and prepolymer, which was prepared by the polycondensation of maleic anhydride and poly (ethylene glycol), using p-toluene sulphonic acid as catalyst. The new copolymer has improved hydrophilicity and flexibility. The structure and properties of the novel polymers were studied by FTIR, NMR, GPC-MALLS and DSC.
Synthesis and characterization of cuprous selenide nanocrystals at room temperature
Tai Shan Li , Shao Pu Liu , Zhao Xia Lu , Zhong Fang Liu
2007, 18(5): 617-620  doi: 10.1016/j.cclet.2007.03.023
[Abstract](161) [FullText HTML] [PDF 754KB](0)
A simple method has been developed to prepare cuprous selenide nanocrystals by the reaction of copper nitrate trihydrate with selenium and sodium mercaptoacetate in aqueous ammonia system. Cu2 Se nanocrystals were characterized by transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), electron diffraction (ED), fluorescence spectrum and ultraviolet-visible absorption spectrum. Cu2 Se nanocrystals showed berzelianite structure with 20-40 nm in length and 10-20 nm in width. A possible mechanism is also discussed.
Quantitative structure-property relationship study of the solubility of thiazolidine-4-carboxylic acid derivatives using ab initio and genetic algorithm-partial least squares
Ali Niazi , Saeed Jameh-Bozorghi , Davood Nori-Shargh
2007, 18(5): 621-624  doi: 10.1016/j.cclet.2007.02.017
[Abstract](152) [FullText HTML] [PDF 191KB](0)
A quantitative structure-activity relationships (QSAR) study is suggested for the prediction of solubility of some thiazolidine-4-carboxylic acid derivatives in aqueous solution. Ab initio theory was used to calculate some quantum chemical descriptors including electrostatic potentials and local charges at each atom, HOMO and LUMO energies, etc. Modeling of the solubility of thiazolidine4-carboxylic acid derivatives as a function of molecular structures was established by means of the partial least squares (PLS). The subset of descriptors, which resulted in the low prediction error, was selected by genetic algorithm. This model was applied for the prediction of the solubility of some thiazolidine-4-carboxylic acid derivatives, which were not in the modeling procedure. The relative errors of prediction lower that -4% was obtained by using GA-PLS method. The resulted model showed high prediction ability with RMSEP of 3.8836 and 2.9500 for PLS and GA-PLS models, respectively.
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