2010 Volume 21 Issue 2

A new shortcut synthesis route for(±)raphidecursinol
Hua Jie Yuan , Yao Yao Cheng , Shan Qian , Xiang Xiao , Yong Wu
2010, 21(2): 127-130  doi: 10.1016/j.cclet.2009.10.027
[Abstract](184) [FullText HTML] [PDF 266KB](0)
The new shortcut synthesis route of(±)raphidecursinol 1,a racemic 8,4'-oxyneolignan compound,can be more easily achieved by the synthesis route,starting from readily available inexpensive 3,4,5-trimethoxybenzaldehyde and 1,2,3-trihydroxybenzene.All structures were confirmed by 1H NMR.IR and MS.
Study on disulfur-backboned nucleic acids:Part Ⅳ.Efficient synthesis of 3',5'-dithio-2'-deoxyguanosine
Pei Hua Shang , Chang Mei Cheng , Hua Wang , Hong Chao Zheng , Yu Fen Zhao
2010, 21(2): 131-134  doi: 10.1016/j.cclet.2009.10.017
[Abstract](189) [FullText HTML] [PDF 225KB](0)
An efficient and novel method for synthesizing 3',5'-dithio-2'-deoxyguanosine was described.In this method normal guanosine was used as the starting material.A very efficient procedure was used to synthesize 2'-O-tosyiguanosine 1,which used 0.1 eq.DBTO instead of 2 eq.1 was treated with LTBH to give 9-(2-deoxy-β-D-threo-pentofuranosyl)guanine 2.2 could be easily turned to the target compound.
A facile synthesis of 2,4,6-trichloroborazine from boron trichloride-dimethylsulfide complex and ammonium chloride
Cheng Deng , Yong Cai Song , Ying De Wang , Yi He Li , Yong Peng Lei , Shu Wei Cao
2010, 21(2): 135-138  doi: 10.1016/j.cclet.2009.10.016
[Abstract](184) [FullText HTML] [PDF 249KB](0)
2,4,6-Trichloroborazine has been recognized as a desirable monomer for the preparation of high-performance boron nitride fibers through polymer derived ceramics route.So a high yield and facile synthesis of 2,4,6-trichloroborazine is essential in practice.Using boron trichloride-dimethylsulfide complex((CH3)2S·BCl3)and ammonium chloride(NH4Cl)as starting materials and toluene(C6H5CH3)as solvent,the synthesis of 2,4,6-trichloroborazine to give high yield is reported.(C)2009 Cheng Deng.Published by Elsevier B.V.on behalf of Chinese Chemical Society.All rights reserved.
Helical twisting properties of new chiral dopants with double (S)-1,2-propanediol units for nematic liquid crystals
Hai Quan Zhang , Wen Ke Liu , Li Cheng Zhao , Wei Huang , Shuai Zhang , Ying Li , Huai Yang
2010, 21(2): 139-142  doi: 10.1016/j.cclet.2009.09.007
[Abstract](169) [FullText HTML] [PDF 707KB](0)
A novel series of chiral dopants synthesized from(S)-1,2-propanediol and mesogenic carboxylic acids were characterized by FT-IR,1H NMR,elemental analysis and their helical twisting properties were investigated by doping the chiral dopants into a nematic liquid crystal host(SLC-1717).The results show that,the helical pitch of N*-LC mixture exhibited a terminal alkyl chain length dependence and the molecular twisting power β also exhibited a temperature dependence(increasing β with increasing temperature).
Synthesis and characterization of yellow water-borne polyurethane using a diol colorant as extender
Jie Zhang , Xing Yuan Zhang , Jia Bing Dai , Wei Hu Li
2010, 21(2): 143-145  doi: 10.1016/j.cclet.2009.10.018
[Abstract](177) [FullText HTML] [PDF 218KB](0)
A novel and facile method toward a series of yellow water-borne polyurethane was developed by using an intrinsically colored diol in this paper.The yellow aqueous dispersion PCLD-HENA-PU was synthesized based on isophorone diisocyanate(IPDI),polycaprolactonediol(PCLD)and 2,2-dimethylol propionic acid(DMPA)using a yellow diol N,N-bis(2-hydroxyethyl)-4-nitroaniline(HENA)as a chain extender.Due to the complete reaction of OH group in colorant HENA with NCO group in diisocyanate,a series of stable yellow polyurethanes could be obtained conveniently and easily.The structure of PCLD-HENA-PUs was confirmed by means of Fourier transform infrared spectroscopy.The UV-visible absorption analysis showed a blue shift effect of about 7 nm when HENA was blocked into polyurethane chain.The absorption intensity of PCLD-HENA-PUs increased with increasing HENA content.It was found that the tensile strength enhanced from 8.6 to 19.6 MPa with HENA content increased from O to 18.0%,while the extensibility decreased from 449 to 300%.The thermal gravimetric analysis presented that the initial decompose temperature began from about 250℃,and had a little increase with increasing the HENA content.
Al(HSO4)3/silica gel as a novel catalytic system for the ring opening of epoxides with thiocyanate anion under solvent-free conditions
Ali Reza Kiasat , Arash Mouradzadegun , Somayeh Elahi , Mehdi Fallah-Mehrjardi
2010, 21(2): 146-150  doi: 10.1016/j.cclet.2009.10.030
[Abstract](182) [FullText HTML] [PDF 445KB](0)
For the first time,metal hydrogen sulfates and phosphates/silica gel have been studied as efficient and powerful solid acid catalysts in the ring opening of epoxides with thiocyanate anion.The most significant result was obtained by Al(HSO4)3/SiO2 which afforded the corresponding β-hydroxy thiocyanates under mild reaction conditions and in very short reaction times.The cheapness,availability of the catalyst,ease of procedure and work-up make this method attractive for the organic synthesis.
A mild and efficient method for nucleophilic aromatic fluorination using tetrabutylammonium fluoride as fluorinating reagent
Yu Feng Hu , Jun Luo , Chun Xu LÜ
2010, 21(2): 151-154  doi: 10.1016/j.cclet.2009.10.014
[Abstract](177) [FullText HTML] [PDF 636KB](0)
Anhydrous tetrabutylammonium fluoride(TBAFanh.)has been found to be a highly efficient fluorinating reagent for nucleophilic aromatic fluorinations such as fluorodenitration or halogen exchange(Halex)reaction.The products were formed in high to excellent yields under surprisingly mild reaction conditions and no phenol or ether side-products were detected in these reactions.
Total synthesis and anticancer activity studies of the stereoisomers of asperphenamate and patriscabratine
Lei Yuan , Jin Hui Wang , Tie Min Sun
2010, 21(2): 155-158  doi: 10.1016/j.cclet.2009.10.004
[Abstract](183) [FullText HTML] [PDF 247KB](2)
All stereoisomers of asperphenamate la and patriscabratine 2a were achieved with a high yield,and total synthesis of 2a is firstly described here.The absolute configuration of patriscabratine was determined as(S,S).The compounds 1a-d and 2a-d have been tested by MTT assay in T47D,MDA-MB231,HL60,Hela and SGC-7901 cell lines in vitro.Among them,the(R,S)stereoisomer shows the strongest anticancer effects,while the(S,R)shows the weakest one.
Optical 2-benzyl-5-hydroxy-4-oxopentanoic acids against carboxypeptidase A:Synthesis,Kinetic evaluation and X-ray crystallographic study
Shou Feng Wang , Jing-Yi Jin , Zong Hao Zeng , Guan Rong Tian
2010, 21(2): 159-162  doi: 10.1016/j.cclet.2009.09.005
[Abstract](177) [FullText HTML] [PDF 1241KB](0)
2-Benzy1-5-hydroxy-4-oxopentanoic acid 1 and its enantiomers were designed,synthesized and assayed for inhibitory activity against carboxypeptidase A(CPA,EC verify the role of the terminal hydroxyl group in 1 binding to CPA,2-benzyl-5benzyloxy-4-oxopentanoic acid 2 was also synthesized and evaluated.The inhibition constants show that both L-1 and D-1 were shown to have strong binding affinity with L-1 being more potent than its enantiomer by 165-fold.On the other hand,the inhibition constant of 2 increases 4-fold comparing with that of 1.In order to explore the exact binding mode of the hydroxyacteyl group of 1 to the active site zinc ion of CPA, we have solved the crystal structure of CPA complexed with L-1 up to 1.85 Å resolution. In CPA L-1 complex,the phenyl ring is fitted in the substrate recognition pocket at the S'1 subsite,and the carboxylate forms bifurcated hydrogen bonds with the guanidinium moiety of Arg-145 and Arg-127 and a hydrogen bond with the phenolic hydroxyl of the downpositioned Tyr-248.The carbonyl oxygen of L-1 does coordinate to the active site zinc ion of CPA as expectedly.Unexpectedly,the terminal hydroxyl group of L-1 is engaged in hydrogen bonding with carbonyl oxygen of Ser-197 instead of coordinating to the active site zinc ion.
Design,synthesis and anti-tumoractivity of novel amidine derivatives of doxifluridine
Ji Lu Feng , Hai Ling Sun , Dong Ping Geng , Ke Li
2010, 21(2): 163-166  doi: 10.1016/j.cclet.2009.10.013
[Abstract](179) [FullText HTML] [PDF 743KB](0)
A series of novel amidine derivatives of doxifluridine were synthesized using acid amide as the starting material,and their antitumor activity was evaluated in A549 cells.Compounds 10 and 11 demonstrated were more potent than 5-Fu,which was used as a positive control.Compound 10,which were found to be the most potent one with IC50 of 3.2 μmol/L,was 16 times more potent than 5-Fu with IC50 of 52 μmol/L to the A549 cells.A new route was designed to synthesize 5'-deoxy-5-fluorocytidine.All compounds were characterized by 1H NMR,MS and X-ray spectras in detail.
Synthesis of chiral dihydrofuran compounds by thiourea derivatives-catalyzed “interrupted” Feist-Bénary reaction
Hui Chen , Ru Jiang , Qiao Feng Wang , Xiao Li Sun , Jing Luo , Sheng Yong Zhang
2010, 21(2): 167-170  doi: 10.1016/j.cclet.2009.10.012
[Abstract](184) [FullText HTML] [PDF 284KB](0)
In this study,six thiourea derivatives of cinchona alkaloids with 9-nat or 9-epi-conflguration were synthesized.After characterized the structures,we adopted them to the asymmetric "interrupted" Feist-Bénary (IFB) reaction of α-haloketones with β-dicarbonyl compounds,to give optically active dihydrofurans.Various thiourea derivatives as organocatalysts were examined.The corresponding chiral hydroxyl dihydrofurans have been obtained in excellent yields and moderate ees.To the acyclic substrate,we obtained exciting and promising result.
2,4,6-Trichloro-1,3,5-triazine/dimethylformamide as an efficient reagent for one-pot conversion of alcohols into N-alkylphthalimides
Babak Mokhtari , Roya Azadi , Aseieh Azhdari
2010, 21(2): 171-174  doi: 10.1016/j.cclet.2009.10.006
[Abstract](191) [FullText HTML] [PDF 352KB](0)
An efficient and mild method for the direct conversion of alcohols into N-alkylphthalimides using 2,4,6-trichloro-1,3,5-triazine and dimethylformamide was described.The reaction was preceded via (alcoxymethylene) dimethylammonium chloride intermediate and produced corresponding N-alkylphthalimides in good-to-excellent yields.
An efficient chemoselective synthesis of O-vinylaryl systems using acetylenic esters and dihydroxybenzenes in the presence of triphenylphosphine or alkyl isocyanides
Robabeh Baharfar , Mohammad Javad Taghizadeh , Majid Ahmadian , Seyed Meysam Baghbanian
2010, 21(2): 175-178  doi: 10.1016/j.cclet.2009.10.007
[Abstract](187) [FullText HTML] [PDF 268KB](1)
The addition of 2,4-dihydroxyaceto(and benzo)phenone to propiolic ester is catalyzed by triphenylphosphine or tert-butyl isocyanide to form O-vinyl aryl derivatives in fairly good yields.
Facile method to synthesize oleic acid-capped magnetite nanoparticles
Chun Yu Wang , Jian Ming Hong , Gong Chen , Yu Zhang , Ning Gu
2010, 21(2): 179-182  doi: 10.1016/j.cclet.2009.10.024
[Abstract](174) [FullText HTML] [PDF 836KB](1)
We described a simple one-step process for the synthesis of oleic acid-capped magnetite nanoparticles using the dimethyl sulfoxide(DMSO)to oxidize the precursor Fe2+ at 140℃.By adjusting the alkalinity of the reaction system,magnetite nanoparticles with two sizes of 4 and 7 nm could be easily achieved.And the magnetite nanoparticles coated by oleate were well-monodispersed in organic solvent.
A green method for the synthesis of bis-indolylmethanes and 3,3'-indolyloxindole derivatives using cellulose sulfuric acid under solvent-free conditions
Heshmatollah Alinezhad , Asefeh Hagh Haghighi , Fatemeh Salehian
2010, 21(2): 183-186  doi: 10.1016/j.cclet.2009.09.001
[Abstract](175) [FullText HTML] [PDF 246KB](0)
A highly efficient green protocol for the preparation of bis-indolylmethanes,bis-2-methylindolylmethanes,bis-1-methylindolylmethanes and 3,3'-diindolyloxindole derivatives from the reaction of indoles with various aldehydes and ketones in the presence of cellulose sulfuric acid under solvent-free conditions is reported.The significant features of this procedure are high yields of the products,mild reaction,solvent-free condition and non-toxicity of the catalyst.
The stable planar conformation of the γ-butyrolactone ring in solution
Zhi Qiang Feng , Cheng Lie Yin
2010, 21(2): 187-190  doi: 10.1016/j.cclet.2009.10.023
[Abstract](175) [FullText HTML] [PDF 508KB](0)
The conformations of γ-butyrolactone ring in solution were deduced on the basis of 1H NMR spectra of geminal protons of the butyrolactone ring.A series of optically pure(Z)-(-)-4-(1'-alkoxyl-1'-carbalkoxy-methylene)-5(R)[(1R)-menthyloxy]-γ-butyr-olactones with a stable planar conformation of γ-butyrolactone ring were found.
A new lathyrane diterpene glycoside from Euphorbia helioscopia L.
Wei Sheng Feng , Li Gao , Xiao Ke Zheng , Yan Zhi Wang , Hui Chen
2010, 21(2): 191-193  doi: 10.1016/j.cclet.2009.10.002
[Abstract](181) [FullText HTML] [PDF 238KB](0)
A new lathyrane diterpene glycoside,named 3β,7β,15β-trihydroxy-14-oxolathyra-5E,12E-dienyl-16-O-β-D-glucopyranoside,was isolated from Euphorbia helioscopia L.Its structure was established by spectroscopic techniques including 2D NMR.
A novel diarylheptanoid bearing flavonol moiety from the rhizomes of Alpinia officinarum Hance
Ling Zhao , Jing Yu Liang , Jing Yu Zhang , Yun Chen
2010, 21(2): 194-196  doi: 10.1016/j.cclet.2009.09.011
[Abstract](176) [FullText HTML] [PDF 215KB](0)
A novel diarylheptanoid bearing flavonol moiety,named officinin A(1),along with two known compounds galangin and kaempferide were isolated from the rhizomes of Alpina officinarum Hance.The structure elucidation was accomplished by HRESI-MS,ID and 2D NMR methods.
A novel alkaloid from the fruiting bodies of Ganoderma sinense Zhao,Xu et Zhang
Chao Liu , Fen Zhao , RuoYun Chen
2010, 21(2): 197-199  doi: 10.1016/j.cclet.2009.07.023
[Abstract](203) [FullText HTML] [PDF 228KB](3)
A new alkaloid,sinensine(1),had been isolated from the fruiting bodies of Ganoderma sinense Zhao,Xu et Zhang.Its structure was elucidated on the basis of ID and 2D spectral analysis.This alkaloid exhibited activity in protecting the injury induced by hydrogen peroxide oxidation on HUVEC,with EC50 value 6.2 μmol/L.
A new ent-kaurane diterpenoid from Isodon japonica
Xue Mei Di , Fu Lin Yan , Chuang Feng , Rui Jie Xie , Rui Jie Hou , Han Dong Sun
2010, 21(2): 200-202  doi: 10.1016/j.cclet.2009.10.029
[Abstract](173) [FullText HTML] [PDF 266KB](0)
One new ent-kaurane diterpenoid,named maoyecrystal L was isolated from the EtOAc extract of the dried leaves of lsodon japonica.Its structure was established by various spectroscopic means and confirmed by X-ray crystallographic analysis.
A new dicaffeoyl quinic acid from Nannoglottis ravid
Jing Jiang , Bei Bei Zhang , Zhi Xin Liao
2010, 21(2): 203-205  doi: 10.1016/j.cclet.2009.10.028
[Abstract](183) [FullText HTML] [PDF 234KB](0)
A new dicaffeoyl quinic acid,nannoglottisin A,has been isolated from an endemic plant of Nannoglottis ravida,and the structure of the compound was identified by means of spectroscopic analysis.
A new tetrahydrophenanthrene from Chloranthus henry
Hui Zheng Fu , Yong Ming Luo , Hua Liu , Dong Ming Zhang , Teng Fei Ji
2010, 21(2): 206-208  doi: 10.1016/j.cclet.2009.10.005
[Abstract](174) [FullText HTML] [PDF 219KB](0)
A new tetrahydrophenanthrene named henryin A(1)was isolated from the leaves of Chloranthus henryi.Its structure was determined to be(S)-4,6,9-trimethyl-5,6,7,8-tetrahydrophenanthrene-1,2-diol on the basis of IR,MS,ID and 2D NMR spectral.
Two new nonacosanetriols from the pollen of Typha angustifolia
Wei Wei Tao , Nian Yun Yang , Jin Ao Duan , De Kang Wu , Er Xin Shang , Da Wei Qian , Yu Ping Tang
2010, 21(2): 209-212  doi: 10.1016/j.cclet.2009.10.025
[Abstract](179) [FullText HTML] [PDF 219KB](1)
Chemical investigation of the pollen of Typha angustifolia Lima.has led to the isolation of two new nonacosanetriols,7,8,10-nonacosanetriol(1)and 7,9,10-nonacosanetriol(2).Their structures were elucidated by chemical reaction and spectral analysis.Compounds 1 and 2 exhibited weak activity of antiplatelet aggregation <>in vitro.
Authentication of Cassia seeds on the basis of two-wavelength HPLC fingerprinting with the use of chemometrics
Yan Hua Lai , Yong Nian Ni , Serge Kokot
2010, 21(2): 213-216  doi: 10.1016/j.cclet.2009.10.031
[Abstract](185) [FullText HTML] [PDF 474KB](0)
High performance liquid chromatographic(HPLC)fingerprints of Cassia seed,a traditional Chinese medicine(TCM),were developed by means of the chromatograms at two wavelengths of 238 and 282 nm.Then,the two data sets were combined into one matrix.The application of principal component analysis(PCA)for this data matrix showed that the samples were clustered into four groups in accordance with the plant sources and preparation procedures.Furthermore,partial least squares(PLS),back propagation artificial neural network(BP-ANN),and radial basis function artificial neural network(RBF-ANN)were effectively applied to predict the category of the four different samples in the test set.
Study on Rhizoma Chuanxiong based on capillary electrophoresis with amperometric detection
Qing Cui Chu , Dong Li Zhang , Hai Tao Zhang , Jian Nong Ye
2010, 21(2): 217-220  doi: 10.1016/j.cclet.2009.10.009
[Abstract](175) [FullText HTML] [PDF 229KB](0)
A high-performance capillary electrophoresis with amperometric detection(CE-AD)method has been developed for the analysis of seven bioactive ingredients,namely ferulic acid(FA),vanillin,vanillic acid,p-hydroxybenzoic acid,caffeic acid,gallic acid and protocatechuic acid,in Rhizoma Chuanxiong.The effects of several factors such as the acidity and concentration of running buffer,the separation voltage,the applied potential to working electrode and the injection time were investigated.Under the optimum conditions,the seven analytes could be well separated within 21 min at the separation voltage of 16 kV in a 60 mmol/Lborax running buffer(pH 8.7).A 300 μm diameter carbon disk electrode has a good response at potential of +950 mV(vs.SCE)for all analytes.Good linear relationship was established over three orders of magnitude with detection limits(S/N=3)ranged from 3.3×10-7 to 6.7×10-9 g/mL.This proposed method has been successfully applied for the determination and comparison of different batches of Rhizoma Chuanxiong samples based on their characteristic electrochemical profiles.
Folded or nonfolded fluorophores incorporating naphthalene:Their fluorescent quenching driven by charge transfer or co-aggregation in the aqueous-organic binary solvent
Qi Zhong Zhou , Shi Yong Liu , Shu Min Zhao , Huang Jiang Jiang
2010, 21(2): 221-224  doi: 10.1016/j.cclet.2009.10.019
[Abstract](174) [FullText HTML] [PDF 295KB](0)
Folded or nonfolded fluorophores incorporating naphthalene were synthesized and characterized by steady state fluorescence technique.Paraquat as an excellent quenching reagent quenched the fuorescence of Nel6 or nDs(n=1-4)driven by charge transfer.Under aggregation of nDs,α-CD did not quench the fluorescence of 1D.At lower concentration,the quenching tendency of α-CD against nDs is 2D > 3D > 4D,while at higher concentration,the tendency is 2D < 3D < 4D.α-CD showed the selective recognition on its fluorescent quenching against 1D,2D,3D and 4D.
Investigation of the oxidation of hydroquinone at the liquid/liquid interface
Xiao Quan Lu , De Fang Dong , Xiu Hui Liu , Dong Na Yao , Wen Ting Wang , Yu Mei Xu
2010, 21(2): 225-228  doi: 10.1016/j.cclet.2009.09.004
[Abstract](154) [FullText HTML] [PDF 234KB](0)
The oxidation of hydroquinone(QH2)was investigated for the first time at liquid/liquid(L/L)interface by scanning electrochemical microscopy(SECM).In this study,electron transfer(ET)from QH2 in aqueous to ferrocene(Fc)in nitrobenzene (NB)was probed.The apparent heterogeneous rate constants for ET reactions were obtained by fitting the experimental approach curves to the theoretical values.The results showed that the rate constants for oxidation reaction of QH2 were sensitive to the changes of the driving force,which increased as the driving force increased.In addition,factors that would affect ET of QH2 were studied.Experimental results indicated ion situation around QH2 molecule could change the magnitude of the rate constants because the capability of oxidation of QH2 would he affected by them.
Calculation model of mass action concentrations for CaO-MgO-SiO2-Al2O3-Cr2O3 penta-slag
Hua Guo , Yu Ting Hu , Da Qiang Cang , Yi Jin , Li Xin Wang , Xiang Li Cheng , Hao Bai , Yan Bing Zong
2010, 21(2): 229-233  doi: 10.1016/j.cclet.2009.10.001
[Abstract](166) [FullText HTML] [PDF 280KB](0)
Two calculation models of mass action concentrations for CaO-MgO-SiO2-Al2O3-Cr2O3 penta-slag was presented whether 3CaO·Cr2O3·3SiO2 was existence or not. Equilibrium mass action concentration of each element structure was gained. And the models results were compared with experimental activity. The final results illustrated the model without 3CaO·Cr2O3·3SiO2 was suit for reality.The model could response the element structure of slag as well.
Preparation of polymeric microspheres with high content of sulphonate groups
Yun Shen Chen , Ji Shuai Wang , Zhao Sheng Hou , Cheng You Kan
2010, 21(2): 234-236  doi: 10.1016/j.cclet.2009.08.016
[Abstract](150) [FullText HTML] [PDF 759KB](0)
Poly(styrene-co-sodium styrene sulphonate)(P(St-NaSS))latex particles were prepared using the mixture of ethanol and water as continuous phase in the presence of surfactant by dispersion-emulsion combined polymerization.The influence of recipes on polymerization process as well as the content of sulphonate group in the purified products was investigated.Results showed that the copolymerization could be performed smoothly.When the mole ratio of NaSS/St/divinyl benzene(DVB)was 25/75/2 and the weight ratio of ethanol/water was 2/11,the product showed a low weight loss in methanol extraction purification,and the NaSS unit ratio in the purified product reached 20.6 tool%,which was close to its theoretical value of 24.9 mol%.
Synthesis and characterization of new biodegradable thermosensitive polyphosphazenes with lactic acid ester and methoxyethoxyethoxy side groups
Yun Mei Bi , Xiao Ying Gong , Wen Zhao Wang , Li Yub , Min Qi Hu , Li Dong Shao
2010, 21(2): 237-241  doi: 10.1016/j.cclet.2009.10.003
[Abstract](155) [FullText HTML] [PDF 338KB](0)
Two novel biodegradable thermosensitive polyphosphazenes with lactic acid ester and methoxyethoxyethoxy side groups were synthesized via the macromolecular substitution reactions of poly(dichlorophosphazene)with the sodium salt of lactic acid ester and sodium methoxyethoxyethoxide.Their structures were confirmed by 31p NMR,1H NMR,13C NMR,IR,DSC,and elemental analysis.The lower critical solution temperature(LCST)behavior in water and in vitro degradation property of the polymers was investigated.The results indicated that two polymers showed LCST phase transition over a range of concentrations from 0.13 to 15 wt% and pH-sensitive degradation properties.
A novel soluble polyamide containing xanthene structure and trifluoromethylphenoxy pendent
Zhen Zhong Huang , Xue Mei Wan , Hai Bo Xiao , Shou Ri Sheng , Cai Sheng Song
2010, 21(2): 242-244  doi: 10.1016/j.cclet.2009.10.011
[Abstract](151) [FullText HTML] [PDF 239KB](0)
A novel polyamide containing xanthene structure and trifluoromethylphenoxy pendent was prepared from 9,9-bis[4-(4aminophenoxy)phenyl]xanthene,a novel diamine with 2-(4-trifluoromethylphenoxy)terephthaloyl chloride,by the low temperature polycondensation.This new polyamide with the inherent viscosity of 0.95 dL/g was amorphous and readily soluble in polar solvents such as DMAc,m-cresol,etc.This polyamide showed the glass transition temperature(Tg)of 236℃,decomposition temperature (Td)at 5% weight loss of 455℃ and char yield of 56% at 800℃ in N2.Transparent,flexible,and tough film of the polymer cast from DMAc solution exhibited tensile strength of 93 MPa,elongation at break of 14%,initial moduli of 2.2 GPa.The electric properties such as the dielectric constant of 3.03(1 MHz)and surface resistance(2.78×1014Ω),and the moisture uptake of 1.36% were also described.
Synthesis and properties of novel low band-gap polymers beating squaraine units
Wei Zhang , Zheng Wang , Yu Sheng Tang , Zhi Gang Xu , Ying Li , Qing Jiang
2010, 21(2): 245-248  doi: 10.1016/j.cclet.2009.09.003
[Abstract](152) [FullText HTML] [PDF 380KB](0)
Novel main-chain-conjugated poly(carbazol-alt-squaraine)and poly(dipyridyl-alt-squaraine)were successfully synthesized through direct polycondensation of 9-(2-ethylhexyl)carbazole-bridged or dipyridyl-bridged bispyrrole and squaric acid.The structures and properties of the polymers were characterized using 1H NMR,FT-IR,UV-vis and cyclic voltammetry.Both polymers exhibit excellent solubility in common organic solvents and good thermal stability.Their UV-vis absorption spectra indicated the polymers have broad and strong spectral responses from 200 nm to 900 nm,which reveals a low optical band gap around 1.38 eV,suggesting that they may be promising candidates for organic solar cells.
Rapid synthesis of biodegradable poly(epsilon-caprolactone-co-p-dioxanone)random copolymers under microwave irradiation
Rui Chen , Jian Yuan Hao , Cheng Dong Xiong , Xian Mo Deng
2010, 21(2): 249-252  doi: 10.1016/j.cclet.2009.10.022
[Abstract](151) [FullText HTML] [PDF 210KB](0)
Biodegradable poly(epsilon-caprolactone-co-p-dioxanone)(PCDO)random copolymers have been synthesized by ring-opening polymerization of epsilon-caprolactone(CL)and p-dioxanone(PDO)under microwave irradiation.The effects of irradiation time and different CL/PDO molar feed ratios on the microwave-assisted ring-opening polymerization(MROP)of PCDO have been discussed.The resultant products were characterized by 1H NMR,GPC and DSC.It was found that the polymerization was completed within 20 min at 140℃.In the presence of different CL/PDO molar feed ratios,the conversions of both monomers were kept relatively constant.DSC study suggested that with increasing the content of PDO in the copolymers,the crystalline degree of the copolymers decreased gradually.It is believed to be a promising biodegradable material.
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