2007 Volume 18 Issue 9

Synthesis and characterization of a novel series of unsymmetrical porphyrins
Lei Wang , Ya Qing Feng , Jin Qiang Xue , Nai Kun Hu
2007, 18(9): 1021-1024  doi: 10.1016/j.cclet.2007.07.021
[Abstract](186) [FullText HTML] [PDF 235KB](0)
Abstract:
A novel series of unsymmetrical porphyrins with aldehyde group at the terminal of the linkage which connected to meso-phenyl through acylamide bond have been synthesized and structurally characterized by IR, 1H NMR, MS, UV-vis, fluorescence.
5-Hexylidene-4-propylamino-1,5-dihydroimidazol-2-one formed from Cu-catalyzed oxidation with implication for the structure of a His-Lys cross-link
Ming Liang Ma , Xiao Yan Li , Ke Wen , Yahu A. Liu
2007, 18(9): 1025-1028  doi: 10.1016/j.cclet.2007.06.025
[Abstract](183) [FullText HTML] [PDF 379KB](0)
Abstract:
Cu-catalyzed oxidation of 5-hexyl-1, 3-dihydroimidazo-2-one (1) in the presence of propylamine, as surrogates for the oxidized His side chain and Lys side chain, was investigated. 5-Hexylidene-4-propylamino-1, 5-dihydroimidazol-2-one (2), a model His-Lys cross-link product, was isolated and structurally characterized by NMR and mass spectrometry.
Triphenylphosphine-catalyzed isomerization of alkynyl ketones in aqueous solution
Qing Fa Zhou , Fei Yang , Qing Xiang Guo , Song Xue
2007, 18(9): 1029-1032  doi: 10.1016/j.cclet.2007.06.024
[Abstract](184) [FullText HTML] [PDF 223KB](0)
Abstract:
An efficient isomerization of alkynyl ketones to (E, E)-diene ketones was developed. The reaction catalyzed by 20 mol%triphenylphosphine in aqueous media gave the desired products in good yields.
Cu-catalyzed arylation of phosphinic amide facilitated by (±)-trans-cyclohexane-1,2-diamine
Juan Li , Song Lin Zhang , Chuan Zhou Tao , Yao Fu , Qing Xiang Guo
2007, 18(9): 1033-1036  doi: 10.1016/j.cclet.2007.07.028
[Abstract](185) [FullText HTML] [PDF 361KB](0)
Abstract:
Cu-catalyzed cross coupling between phosphinic amides and aryl halides was accomplished for the first time by using (±)-trans-cyclohexane-1, 2-diamine as the ligand. This reaction provided a novel approach for synthesizing arylated phosphinic amides. Both kinetic measurement and theoretical calculation indicated that phosphinic amides were much less reactive than amides by about 10times in Cu-catalyzed cross coupling.
A new efficient route for the synthesis of 4,4',6,6'-tetra (azido) azo-1,3,5-triazine
Xiao Tong Li , Sheng Hua Li , Si Ping Pang , Yong Zhong Yu , Yun Jun Luo
2007, 18(9): 1037-1039  doi: 10.1016/j.cclet.2007.06.028
[Abstract](179) [FullText HTML] [PDF 211KB](0)
Abstract:
A new method for the synthesis of 4, 4', 6, 6'-tetra (azido) azo-1, 3, 5-triazine (TAAT) is described. The key intermediate 4, 4', 6, 6'-tetra (azido) hydrazo-1, 3, 5-triazine (THAT) was synthesized by nucleophilic substitution in the case of sodium azide as nucleophile. N-Bromosuccinide (NBS) was used as oxidant to oxidize THAT by a tractable operation under mild reaction condition. The target compound TAAT was obtained with a facile process and high overall yield of 81%. The structures of TAAT and its intermediates were identified by spectroscopic methods.
Copper-mediated 1,4-conjugation reaction of functionalized alkylzinc iodides with derivatives of β-nitrostyrene
Dan Feng Huang , Yu Lai Hu , Jin Xian Wang
2007, 18(9): 1040-1042  doi: 10.1016/j.cclet.2007.06.017
[Abstract](183) [FullText HTML] [PDF 197KB](0)
Abstract:
Functionalized alkylzinc iodides will undergo 1, 4-conjugation reaction with derivatives of β-nitrostyrene in the presence of Cu (Oac) 2/LiCl to afford a polyfunctional nitro-compound in high yield.
Palladium-catalyzed homo-coupling of boronic acids with supported reagents in supercritical carbon dioxide
Lei Zhou , Qiu Xiang Xu , Huan Feng Jiang
2007, 18(9): 1043-1046  doi: 10.1016/j.cclet.2007.06.023
[Abstract](180) [FullText HTML] [PDF 183KB](0)
Abstract:
Palladium-catalyzed homo-coupling of arylboronic acids could proceed smoothly with a commercially available resin functionlised by phosphino or amino group as the ligand in supercritical carbon dioxide thereby offering a simple and efficient protocol for the synthesis of symmetrical bi-aryl molecules and their higher homologues.
One-pot synthesis of 2,5-disubstituted-l,3,4-thiadiazoles under ultrasonic irradiation
Ying Jun Li , Ya Zhen Sun , Yong Ting Xu , Kun Jin , Li Ping Wen , Ni Bo Hou , Xiao Xiao Sun
2007, 18(9): 1047-1048  doi: 10.1016/j.cclet.2007.05.049
[Abstract](184) [FullText HTML] [PDF 226KB](0)
Abstract:
A facile one-pot synthesis of 2, 5-disubstituted-1, 3, 4-thiadiazoles was achieved by ultrasonic irradiation of a mixture of lnaphthylacetyl chloride, NH4CNS, CH2Cl2 and PEG-400 for 1.5 h at 10-20℃ and subsequent irradiation for 1.5 h in the presence of N-arylglycine hydrazides. This method requires short time and gives thiadiazoles in high yields.
Preparation of natural isovaleraldehyde by the Maillard reaction
Hong Yu Tian , Jie Zhang , Bao Guo Sun , Ming Quan Huang , Jian Rong Li , Xiao Xiang Han
2007, 18(9): 1049-1052  doi: 10.1016/j.cclet.2007.07.009
[Abstract](187) [FullText HTML] [PDF 227KB](1)
Abstract:
Isovaleraldehyde possesses malty, fruity, cocoa-like odor and is widely used in fruit, chocolate, coffee flavors. The preparation of natural isovaleraldehyde by the Maillard model reaction was studied in this paper. The effects of the ratio of D-glucose/L-leucine, reaction temperature and pH value on the yield of isovaleraldehyde were explored. The optimum conditions were as follows:n (D-glucose):n (L-leucine)=4, temperature 150℃, reaction time 3 h, pH 5. The highest yield of isovaleraldehyde obtained was about 32%.
Selective oxidation of ethylbenzene catalyzed by fluorinated metalloporphyrins with molecular oxygen
Xiao Gang Li , Jing Wang , Ren He
2007, 18(9): 1053-1056  doi: 10.1016/j.cclet.2007.06.019
[Abstract](195) [FullText HTML] [PDF 201KB](0)
Abstract:
This paper reported the oxidation of ethylbenzene catalyzed by fluorinated metalloporphyrins under mild conditions without any additives. The results showed that the cobalt (Ⅱ) (5, 10, 15, 20-tetrakis (pentafluorophenyl)) porphyrin was the best catalyst among the fluorinated metalloporphyrins. The conversion of ethylbenzene reached 38.6%, the selectivity to acetophenone reached 94.0%, and the turnover number is 2719 under the optimal conditions.
Ruthenium (Ⅲ) chloride as an efficient catalyst for the synthesis of perimidine derivatives under mild conditions
Jing Zhang , Song Lin Zhang , Jun Min Zhang
2007, 18(9): 1057-1060  doi: 10.1016/j.cclet.2007.07.004
[Abstract](176) [FullText HTML] [PDF 230KB](0)
Abstract:
Various biologically important perimidine derivatives have been synthesized efficiently from various ketones and naphthalene-1, 8-diamine by using a catalytic amount of RuCl3 (1 mol%). This method is a very simple and high yielding reaction for the synthesis of perimidine derivatives.
Indium-mediated allylation of aryl trichloromethyl ketones in aqueous media
Zhi Jian Bao , Jun Lu , Shun Jun Ji
2007, 18(9): 1061-1063  doi: 10.1016/j.cclet.2007.07.035
[Abstract](188) [FullText HTML] [PDF 134KB](0)
Abstract:
It is described that indium-mediated allylation of trichloromethyl ketones could afford the corresponding homoallylic alcohols smoothly in aqueous media.
Wet carbon-based solid acid/NaNO3 as a mild and efficient reagent for nitration of aromatic compound under solvent free conditions
Arash Shokrolahi , Abbas Zali , Mohammad Hossein Keshavarz
2007, 18(9): 1064-1066  doi: 10.1016/j.cclet.2007.06.031
[Abstract](191) [FullText HTML] [PDF 217KB](1)
Abstract:
Nitro aromatic compound can be obtained in high yields via nitration of aromatic compound with wet carbon-based solid acid and NaNO3 under solvent free oxidation at room temperature.
K2CO3 catalyzed solvent-free synthesis of molecular tweezers containing chiral unsymmetrical urea unit under microwave irradiation
Zhi Gang Zhao , Xing Li Liu , Cai E. Zhou
2007, 18(9): 1067-1070  doi: 10.1016/j.cclet.2007.06.030
[Abstract](180) [FullText HTML] [PDF 215KB](0)
Abstract:
A facile, rapid and efficient method for the synthesis of molecular tweezers containing chiral unsymmetrical urea unit in solventfree conditions using microwave was reported.
Synthesis and surface activity of a novel heterodouble chained N-acyltaurate amphiphile
Feng Yan , Zhi Cheng Xu , Qing Tao Gong , Zhi Qiang Jin , Jing Yi An , Sui Zhao , Jia Yong Yu
2007, 18(9): 1071-1074  doi: 10.1016/j.cclet.2007.07.005
[Abstract](182) [FullText HTML] [PDF 286KB](0)
Abstract:
A novel double chained amphiphile, N-(α-4-hexylphenoxy)-lauroyltaurate (abbreviated as 10+6B-T), has been synthesized. The structures of main intermediate products and the title product were characterized by 1H NMR. The new amphiphile shows high surface activity. The critical micelle concentration (cmc), which is 1.1×10-5 mol/L, is much lower than that of conventional double chained surfactants, such as sodium bis (2-ethylhexyl) sulfosuccinate (AOT).
Two new α,β-unsaturated butyrolactone derivatives from Pleione bulbocodioides
Xin Qiao Liu , Wen Yuan Gao , Yuan Qiang Guo , Tie Jun Zhang , Lu Lu Yan
2007, 18(9): 1075-1077  doi: 10.1016/j.cclet.2007.06.022
[Abstract](183) [FullText HTML] [PDF 197KB](0)
Abstract:
Two new α, β-unsaturated butyrolactone derivatives, 4-(4"-hydroxybenzyl)-3-(3'-hydroxy-phenethyl) furan-2 (5H)-one (1) and 3-(3'-hydroxyphenethyl) furan-2 (5H)-one (2), together with one known phenolic compound (3), were isolated from the tubers of Pleione bulbocodioides (Franch.) Rolfe. Their structures were elucidated by analysis of spectroscopic data.
A new triterpenoid saponin from Clematis ganpiniana
Feng Sun , Qing He , Pei Gen Xiao , Yi Yu Cheng
2007, 18(9): 1078-1080  doi: 10.1016/j.cclet.2007.06.026
[Abstract](177) [FullText HTML] [PDF 203KB](0)
Abstract:
A new triterpenoid saponin, named clematiganoside A (1), was isolated from the whole plant of Clematis ganpiniana. Its structure was elucidated on the basis of 1D, 2D NMR, TOF-MS and ESI-MS techniques, and physicochemical properties.
A new cyclodipeptide from the cultures of Geotrichum candidum
Ya Nan Liu , Jing Hua Xue , Na Feng , Ping Wu , Xing Zhong Liu , Xiao Yi Wei
2007, 18(9): 1081-1083  doi: 10.1016/j.cclet.2007.07.003
[Abstract](179) [FullText HTML] [PDF 208KB](0)
Abstract:
A new cyclodipeptide, cyclo (phenylalanyl-N-methyltyrosyl) 1, was isolated from the mycelial solid cultures of Geotrichum candidum. Its structure was elucidated by spectroscopic methods. The antifungal activity of the new compound against Peronophythora litchii was assessed by microplate Alamar blue assay (MABA).
Two new indole alkaloids from Nauclea officinalis
Jing Yong Sun , Hong Xiang Lou , Hui Xu , Sheng Jun Dai , Ke Liu
2007, 18(9): 1084-1086  doi: 10.1016/j.cclet.2007.07.006
[Abstract](181) [FullText HTML] [PDF 220KB](0)
Abstract:
Two new indole alkaloids, 4-oxo-4, 12-dihydroindolo[2, 3-a]quinolizine-3-carbaldehyde (1) and 1, 6, 7-trihydro-indolo-[2, 3-a]furan[3, 4-g]quinolizine-3, 4 (13H)-dione (2), were isolated from Nauclea officinalis. Their structures were determined on the basis of 1D and 2D NMR spectral data.
A phenolic glycoside from Fagopyrum dibotrys (D.Don) Hara
Zheng Zhong Bai , Xiao Hui Zhang , Li Jiang Xuan , Feng Kui Mo
2007, 18(9): 1087-1088  doi: 10.1016/j.cclet.2007.07.033
[Abstract](181) [FullText HTML] [PDF 202KB](0)
Abstract:
A new phenolic constituent along with five known compounds were isolated from Fagopyrum dibotrys (D. Don) Hara. The new compound was characterized as 1, 3-dimethoxy-2-O-β-xylo-pyranosyl-5-O-β-glucopyranosyl-benzene, by spectroscopic analysis and enzymatic hydrolysis.
A new phenanthro[2,3-b]furan from Pleione bulbocodioides
Xin Qiao Liu , Wen Yuan Gao , Yuan Qiang Guo , Tie Jun Zhang , Lu Lu Yan
2007, 18(9): 1089-1091  doi: 10.1016/j.cclet.2007.07.011
[Abstract](189) [FullText HTML] [PDF 193KB](0)
Abstract:
A novel phenanthro[2, 3-b] furan 1, named (3-hydroxy-9-(4'-hydroxy-3'-methoxyphenyl)-11-methoxy-5, 6, 9, 10-tetrahydrophenanthro[2, 3-b] furan-10-yl) methyl acetate, and two known phenolic compounds were isolated from the tubers of Pleione bulbocodioides (Franch.) Rolfe. Their structures were elucidated by spectroscopic methods.
A new isoflavane from processed Astragalus membranaceus
Wei Liu , Jing Chen , Wen Jian Zuo , Xian Li , Jin Hui Wang
2007, 18(9): 1092-1094  doi: 10.1016/j.cclet.2007.07.036
[Abstract](186) [FullText HTML] [PDF 221KB](0)
Abstract:
A new isoflavane named astraganoside, together with five known compounds had been isolated from the processed Astragralus membranaceus. The structure of the novel compound was elucidated as (3R, 4R)-3-(2-hydroxy-3, 4-dimethoxyphenyl) chroman-4, 7-diol-7-O-β-D-glucopyranoside (1) based on spectroscopic methods including UV, IR, ESI-MS, 1D NMR and 2D NMR techniques.
A novel method for Co (Ⅱ) and Cu (Ⅱ) analysis by capillary electrophoresis with chemiluminescence detection
Xiao Ming Guo , Xiang Dong Xu , Hui Jing Zhang , Yong Gang Hu , Jie Zhang
2007, 18(9): 1095-1098  doi: 10.1016/j.cclet.2007.06.015
[Abstract](168) [FullText HTML] [PDF 293KB](0)
Abstract:
Based on the fact that some metal ions can catalyze the chemiluminescence (CL) reaction of luminol with K3Fe (CN) 6, a novel capillary electrophoresis CL method was developed for the determination of Co (Ⅱ) and Cu (Ⅱ). The separation was carried out with a 10 mmol/L sodium acetate solution containing 0.8 mmol/L luminol and 2.0 mmol/L α-HIBA (adjusted to pH 4.8 by Hac solution). The post-capillary reagent was 2.0 mmol/L K3Fe (CN) 6which was adjusted to pH 13.0 by NaOH solution. Under the optimum conditions, the detection limits (S/N=3) for Co (Ⅱ) and Cu (Ⅱ) were 7.5×10-11 mol/L and 7.5×10-9 mol/L, with the linear range of 7.5×10-9 mol/L to 1.0×10-6 mol/L and 7.5×10-8 mol/L to 5.0×10-5 mol/L, respectively.
Determination of sodium hyaluronate with some basic bisphenylnaphthylmethane dyes by resonance Rayleigh scattering method
Lian Hui Chen , Yi Jian , Hong Qun Luo , Shao Pu Liu , Xiao Li Hu
2007, 18(9): 1099-1102  doi: 10.1016/j.cclet.2007.06.020
[Abstract](179) [FullText HTML] [PDF 257KB](0)
Abstract:
In an acetic acid-sodium acetate buffer solution of pH 3.6-6.8, a compound complex was formed between sodium hyaluronate (abbreviated as SH) and some basic bisphenylnaphthylmethane dyes, leading to a great enhancement of the intensity of resonance Rayleigh scattering (RRS) and giving a new RRS spectrum, with its maximum scattering peak near 280 nm. It was also found that the intensity of RRS was directly proportional to the concentration of SH near the range between 0 and 3.0 mg/L. Based on these facts, a sensitive method for the determination of SH has been established. The method had good selectivity, and has been used for the determination of total amounts of SH in samples with satisfactory results. For the NB-SH system, the detection limit of SH was down to 13.7 ng/mL.
Potentiometric determination of diclofenac in pharmaceutical formulation by membrane electrode based on ion associate with base dye
Zholt Kormosh , Iryna Hunka , Yaroslav Bazel
2007, 18(9): 1103-1106  doi: 10.1016/j.cclet.2007.07.007
[Abstract](190) [FullText HTML] [PDF 219KB](0)
Abstract:
The characteristics, performance and application of membrane electrode based on ion associate of diclofenac with base dye Safranine T are described. The electrode response to diclofenac has the sensitivity of 47±1.0 mV decade-1 over the range of 5×10-5 to 5×10-2 mol/L at pH 6-12, and the detection limit of 3.2×10-5 mol/L. The electrode is easy assembled at a relatively low cost has fast response time (2-4 s) and can be used for a period up to 3.5 months without any considerable divergence in potential. The proposed sensor displayed good selectivity for diclofenac in the presence of different substances. It was used to determine diclofenac in pharmaceuticals by means of the standard addition method.
Development of ELISA and immunochromatographic assay for ofloxacin
Wu Yong Sun , Wen Ying Liu , Ling Bo Qu
2007, 18(9): 1107-1110  doi: 10.1016/j.cclet.2007.07.008
[Abstract](167) [FullText HTML] [PDF 718KB](1)
Abstract:
Two rapid, sensitive and reliable immunoassay methods, namely competitive indirect enzyme-linked immunosorbent assay (CIELISA) and colloidal gold-based immunochromatographic assay (CGIA), were developed to detect ofloxacin (OFL). The linear range of the CI-ELISA was from 0.5 to 128 ng/mL with a limit of detection (LOD) of 0.35 ng/mL. Good recoveries were obtained in analyzing simulated swine urine samples. The CGIA could accurately estimate OFL at concentrations as low as 10 ng/mL in less than 10 min, and test results were read visually without any instrument.
Voltammetric determination of uric acid by using gold nanotubule electrode
Yue Rong Wang , Ping Hu , Qiong Lin Liang , Guo An Luo , Yi Ming Wang
2007, 18(9): 1111-1114  doi: 10.1016/j.cclet.2007.07.034
[Abstract](182) [FullText HTML] [PDF 771KB](0)
Abstract:
Gold nanotubule membranes were prepared by using electroless deposition of gold within the pores and surfaces of polycarbonate track-etched membranes. And the gold nanotubule membrane was used as an electrode for determination of uric acid in urine samples for the first time. In Britton-Robinson buffer of pH 4.56, uric acid exhibited well-defined differential pulse voltammograms. And the interference between coexistent ascorbic acid and uric acid was overcome owing to the attractive ability of the gold nanotubule electrode to yield a large anodic peak difference ca. 0.404 V (vs. SCE). The proposed method was then applied to the determination of uric acid in urine without any pretreatment.
Calcium-binding ability of soy protein hydrolysates
Xiao Lan Bao , Mei Song , Jing Zhang , Yang Chen , Shun Tang Guo
2007, 18(9): 1115-1118  doi: 10.1016/j.cclet.2007.07.032
[Abstract](185) [FullText HTML] [PDF 244KB](0)
Abstract:
This present study investigated the ability of various soy protein hydrolysates (SPHs) in binding calcium. It was demonstrated that the amount of Ca-bound depended greatly on the SPHs obtained using different proteases, which included:neutrase, flavourzyme, protease M and pepsin. The maximum level of Ca-bound (66.9 mg/g) occurred when protease M was used to hydrolyze soy protein. Peptide fragments exhibiting high Ca-binding capacity had molecular weights of either 14.4 or 8-9 kDa. The level of Ca-bound increased linearly with the increment of carboxyl content in SPHs, and further deamidation on SPHs from protease M improved Ca-binding of the hydrolysate.
Synthesis and phosphorescent properties of two novel iridium (Ⅲ) complexes bearing bulky tert-butyl substituents
Rong Huang , Xiao Qiang Wei , Tai Ping Zhang , Zhi Yun Lu , Ming Gui Xie
2007, 18(9): 1119-1123  doi: 10.1016/j.cclet.2007.06.008
[Abstract](173) [FullText HTML] [PDF 318KB](0)
Abstract:
The synthesis and phosphorescence properties of two novel Ir (Ⅲ) complexes bearing tert-butyl substituents, bis (4-tert-butyl-2-phenylbenzothiozolato-N, C2') iridium (Ⅲ) (acetylacetonate)[(tbt) 2Ir (acac)] and bis (4-tert-butyl-1-phenyl-1H-benzimidazolatoN, C2') iridium (Ⅲ) (acetylacetonate)[(tpbi) 2Ir (acac)], are reported, their molecular structures are confirmed by 1H NMR, ESI-MS and elementary analysis. Photoluminescence (PL) studies revealed that they can emit strong green and orange phosphorescence in high quantum yields. Compared to their prototypes lacking of tert-butyl substituents, the two novel iridium (Ⅲ) complexes both have shorter lifetimes and improved or nearly similar PL quantum efficiencies, implying that the exciton quenching is inhibited effectively when molecular steric hindrance increases. The two chelates have great potential to be used as electrophosphorescent materials.
Electrochemical formation and phase control of Mg-Li alloys
Mi Lin Zhang , Zeng Chen , Wei Han , Yan Zhuo Lv , Jun Wang
2007, 18(9): 1124-1128  doi: 10.1016/j.cclet.2007.07.014
[Abstract](200) [FullText HTML] [PDF 951KB](0)
Abstract:
The electrochemical formation of Mg-Li alloys was investigated in a molten LiCl-KCl (58-42 mol%) eutectic melt at 723 K. The cyclic voltammogram for a Mo electrode showed that the electroreduction of Li+ proceeds in a single step and the deposition potential of Li metal was -2.40 V (vs. Ag/AgCl). For Mg electrode, the electroreduction of Li+ takes place at less cathodic potential than that at the Mo electrode which was caused by the formation of Mg-Li alloys. Phase of the deposited Mg-Li alloys could be controlled by the electrolysis potential, and the samples were characterized by X-ray diffraction and scanning electron microscopy. The results showed that α-Mg and β-Li phases were obtained at -2.35 and -2.55 V, respectively.
Effect of spacer length on the liquid crystalline property of azobenzene-containing ABA-type triblock copolymers via ATRP
Xin De Tang , Long Cheng Gao , Xing He Fan , Qi Feng Zhou
2007, 18(9): 1129-1132  doi: 10.1016/j.cclet.2007.06.016
[Abstract](169) [FullText HTML] [PDF 1352KB](0)
Abstract:
The effect of flexible spacer length on the liquid crystalline property of ABA-type triblock copolymers containing azobenzene groups was investigated. For the study, the monomers, n-[4-(4-ethoxyphenylazo) phenoxy]alkyl methacrylates with varying methylene groups (n=0, 2, 6) were used to synthesize a series of azobenzene-containing amphiphilic triblock copolymers PAnC-PEG-PAnC by atom transfer radical polymerization (ATRP). Differential scanning calorimetry (DSC), polarizing optical microscopy (POM), and one-dimensional X-ray diffraction (1D WAXD) have shown that the glass transition temperatures of these copolymers decreased with increasing n, PA0C-PEG-PA0C has no mesophase, while both PA2C-PEG-PA2C and PA6C-PEGPA6C have a nematic mesophase. These differences derive from the length of spacer groups between the polymer backbone and side-chain LC monomers.
Lanthanum heterocyclic Schiff-base complex initiated ring-opening polymerization of ε-caprolactone
Wen Lin , Wei Lin Sun , Zhi Quan Shen
2007, 18(9): 1133-1136  doi: 10.1016/j.cclet.2007.06.021
[Abstract](187) [FullText HTML] [PDF 269KB](0)
Abstract:
Lanthanum complex supported by the heterocyclic Schiff-base ligand of N-(2-pyridyl)-3, 5-di-tert-butyl-salicylaldimine was prepared and employed for the ring-opening polymerization (ROP) of ε-caprolactone (ε-CL). The polymers obtained with this initiator showed a unimodal molecular weight distribution implied that only one active species was present. Mechanism study revealed that the polymerization proceeds via acyl-oxygen bond cleavage.
Synthesis and characterization of trimethoxysilyl-functionalized poly (phthalazinone ether ketone)
Qi Feng Jin , Gong Xiong Liao , Xi Gao Jian
2007, 18(9): 1137-1140  doi: 10.1016/j.cclet.2007.06.029
[Abstract](188) [FullText HTML] [PDF 257KB](0)
Abstract:
A novel alkoxysilyl-functionalized poly (phthalazinone ether ketone) (PPEK) was prepared for the boundary lubricant application in micro-electro-mechanical system (MEMS). The synthesis of functionalized PPEK was started from the hydroxylation of PPEK, then following with the corresponding ring-opening reaction of 3-glycidoxypropyltrimethoxysilane (GPTMS). The structures of the functional PPEK were confirmed by FTIR, 1H NMR, 29Si NMR, and UV-vis spectrum.
Homopolymerization of N-pyrimidinyl acrylamide
De Cheng Wan , Hong Ting Pu , Gen Jin Yang
2007, 18(9): 1141-1144  doi: 10.1016/j.cclet.2007.07.037
[Abstract](182) [FullText HTML] [PDF 574KB](0)
Abstract:
Homopolymerization of N-pyrimidinyl acrylamide (NPA) was reported for the first time. The polymer (polyNPA) was soluble only in acidic media and fluoroalcohols, and only in fluoroalcohol was homogeneous polymerization of NPA feasible. 1H NMR analysis proved that a 1:1 H-bonding complex could be formed between NPA and α, α-bis (trifluoromethyl) phenyl propan-2-ol (BTMP). Cumyl dithiobenzoate mediated reversible addition-fragmentation chain transfer (RAFT) polymerization of NPA in BTMP was carried out. 1H NMR analyses proved that the molecular weight increased linearly with the monomer conversion. The polymer prepared in conventional solvents was atactic while in protic media the syndiotacticity was slightly enhanced.
Synthesis of new N-alkylsulfonamide-containing phenylazopyrazolone dyes and their application to unmodified polypropylene fiber
Zhi Hua Cui , Shu Fen Zhang , Jin Zong Yang
2007, 18(9): 1145-1147  doi: 10.1016/j.cclet.2007.06.027
[Abstract](184) [FullText HTML] [PDF 214KB](0)
Abstract:
Three new N-alkylsulfonamide-containing phenylazopyrazolone dyes have been synthesized by reaction of sulfonyl chloride intermediates with different saturated aliphatic amines and their molecular structures were confirmed by FTIR, 1H NMR and MS. The dyes were applied to unmodified polypropylene fabric. These dyes showed high exhaustion as well as higher levels of fastness to washing, sublimation and rubbing compared with C. I. Disperse Yellow 16. The results showed the N-alkylsulfonamide-containing dyes were suitable for dyeing unmodified PP fiber and exhibited good color depth and fastness properties.
Synthesis and characterization of novel sulfonated polyimide containing phthalazinone moieties as PEM for PEMFC
Hai Yan Pan , Yong Fang Liang , Xiu Ling Zhu , Xi Gao Jian
2007, 18(9): 1148-1150  doi: 10.1016/j.cclet.2007.06.032
[Abstract](204) [FullText HTML] [PDF 190KB](0)
Abstract:
A novel sulfonated diamine monomer, 1, 2-dihydro-2-(3-sulfonic-4-aminophenyl)-4-[4-(4-aminophenoxy)-phenyl]phthalazinl-one (S-DHPZDA), was successfully synthesized by direct sulfonation of diamine 1, 2-dihydro-2-(4-aminophenyl)-4-[4-(4-aminophenoxy)-phenyl]-phthalazin-1-one (DHPZDA). A series of sulfonated polyimides (SPIs), which can be used as the material of the proton exchange membrane (PEM) for the proton exchange membrane fuel cell (PEMFC), were prepared from 1, 4, 5, 8-naphthalenetetracarboxylic dianhydride (NTDA), S-DHPZDA, and nonsulfonated diamines DHPZDA. The structure of the monomer and polymers were characterized by FT-IR and 1H NMR. The solubility of the S-DHPZDA-based SPIs has been improved due to the induction of the phthalazione moiety. The SPIs membranes have high thermo-stability, predominant swelling resistance with high ion exchange capacity.
Dyes with high affinity for polylactide
Liang He , Shu Fen Zhang , Bing Tao Tang , Li Li Wang , Jin Zong Yang
2007, 18(9): 1151-1153  doi: 10.1016/j.cclet.2007.07.031
[Abstract](183) [FullText HTML] [PDF 183KB](0)
Abstract:
Attempts were made to develop dyes with high affinity for polylactide as an alternative to the existent commercial disperse dyes. The dyes synthesized according to the affinity concept of dye to polylactide exhibited excellent dyeing properties on polylactide compared with the commercial disperse dyes.
Joule-Thomson inversion curve prediction by using equation of state
Behzad Haghighi , Mohammad Reza Hussaindokht , Mohammad Reza Bozorgmehr , Naser Seyed Matin
2007, 18(9): 1154-1158  doi: 10.1016/j.cclet.2007.07.002
[Abstract](190) [FullText HTML] [PDF 322KB](0)
Abstract:
In this paper five equations of state are tested for checking their ability to predict the Joule-Thomson inversion curve. These five equations of state are:Mohsennia-Modarres-Mansoori (MMM), Ji-Lemp (JL), modified Soave-Redlich-Kwang (SRK) equation of state by Graboski (MSRK1), modified SRK equation of state by Peneloux and Rauzy (MSRK2), and modified Peng-Robinson (PR) equation of state by Rauzy (PRmr). The investigated equations of state give good prediction of the low-temperature branch of the inversion curve, except for MMM equation of state. The high-temperature branch and the peak of the inversion curve have been observed, in general, to be sensitive to the applied equation of state. The values of the maximum inversion temperature and maximum inversion pressure are calculated for each component used in this work.
The theoretical study of one-carbon unit transfer with H2O participation from imidazolidine to dUMP analogue
Chuan Song Qi , Wei Li , Xin Min Wu , Lei Xu , Da Cheng Feng
2007, 18(9): 1159-1162  doi: 10.1016/j.cclet.2007.07.001
[Abstract](187) [FullText HTML] [PDF 236KB](0)
Abstract:
The ONIOM quantum mechanics method is used to study the reaction of one-carbon unit transfer from an imidazolidine to 6-aminouracil model with the participation of water molecules. The computation results show that in this reactionthe participation of H2O molecule makes the energy barrier lower because of the H-bond interaction.
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