1996 Volume 7 Issue 1

REGIOSELECTIVITY OF PHOTOINDUCED INTRAMOLECULAR ARENE-OLEEIN META-CYCLOADDITION
Cong ZHANG , Xiao Chuan GUO , Xiu Min SHEN
1996, 7(1): 1-4
[Abstract](167) [FullText HTML] [PDF 135KB](0)
Abstract:
The photoinduced intramolecular arene-olefin meta-cycloaddition of 1 gave regio-selectixely products 2a and 2b,whereas under the same conditions, 3a and 3b provided 4a and 4b respectively.The structure of the photo products was established by detailed 2D-NMR methodology.The observed regioselectivity was rationalized in terms of the stabilization of the zwitterionic intermediates by alkyl group at the phenyl ring.
STUDIES ON THE ADDITION REACTION OF GRIGNARD REAGENTS TO α-CINNAMOYLKETENE(1,3-PROPYLENE)DITHIOACETALS
Qun Xing FANG , Chun LIN , Shu Jia ZHANG , Qun LIU
1996, 7(1): 5-6
[Abstract](159) [FullText HTML] [PDF 70KB](0)
Abstract:
The addition reaction of Grignard reagents to α-cinnamoyl ketene (1,3-propylene) dithioacetals was performed.The experiments show that the addition proceeds completely in a conjugated 1,4-manner.Possible mechanism for the reaction selectivity is discussed.
PREPARATION OF BENZIL BY OXIDATION WITH AIR
Ke Da ZHANG , Roug FAN
1996, 7(1): 7-8
[Abstract](174) [FullText HTML] [PDF 90KB](3)
Abstract:
Oxidation of benzoin with air in the presence of a catalytic amount of cobalt salts was studied.By this reaction,benzil was conveniently prepared in excellent yield.
MANNICH REACTION ON 1,2-DIHYDRO-1-PYRROLIZINONE
Shao Jie , WANG , Fu Shuang LIU , Shou Fang ZHANG
1996, 7(1): 9-10
[Abstract](737) [FullText HTML] [PDF 69KB](0)
Abstract:
The aminomethylation of the title compound can occur at 2-C or 5-C when it undergoes Mannich reaction with different amines.With aliphatic secondary amines,the reaction occurs at 2-C of the ketone,whereas with aromatic primary amines under certain conditions,at 5-C of the ketone.
STUDIES ON THE PRENYLFLAVONOIDS PART X IX SYNTHESIS OF EXIGUAFLAVANONE K
Xian Yong BU , Li XIAO , Yu Lin LI
1996, 7(1): 11-12
[Abstract](159) [FullText HTML] [PDF 73KB](1)
Abstract:
Exiguaflavanone K was first synthesized via the condensation of 2-hydroxy-3-prenyl-4,6-dimethoxymethoxyacetophenone with 3-methoxy-4-methoxymethoxybenzaldehyde followed by cyciization and demethoxymethylation.
STUDIES ON THE CRINUM ALKALOIDS PART I: SYNTHESIS OF ANHYDROLYCORINE-7-ONE
Hua Wu SHAO , Jun Chao CAI
1996, 7(1): 13-14
[Abstract](257) [FullText HTML] [PDF 81KB](0)
Abstract:
Palladium acetate catalyzed cyclization of 1-[(6-bromo-1,3-benzodioxol-5-yl)carbonyl] 2,3-dihydro-1H-indole (7a) leading to the anhydrolycorine-7-one (1a) as the key step in a new synthesis of Crinum alkaloids is described.
SYNTHESIS OF NOVEL TRLACETAL OXA-CAGE COMPOUNDS
Hsien Jen WU , Chung Yi WU , Chu Chang LIN
1996, 7(1): 15-18
[Abstract](158) [FullText HTML] [PDF 126KB](0)
Abstract:
Ozonolysis of compounds 3a-3e and 6 in dichloromethane at-78℃ followed by reduction with dimethylsulfide gave the novel triacetal oxa-cage compounds 5a-5e and 7 in moderate yields respectively.
THE ISOLATION AND CHEMICAL STRUCTURE OF ISOANNONARETICINS,A PAIR OF 2-EPIMERS FROM ANNONA RETICULATA (ANNONACEAE)
Jing Guang YU , Dong LIU
1996, 7(1): 19-22
[Abstract](231) [FullText HTML] [PDF 136KB](0)
Abstract:
A new acetogenin 2,4-cis-isoannonareticin (2-1) (2,4-cis-bullatacinone) and a known bullatacinone (2,4-trans-isoannonareticin) (2-2) were a pair of isomers epimeric at C-2 which were isolated as two pure natural compounds from Annona reticulata L. by using preparative TLC.Their structures and the relative stereochemistry were elucidated on the basis of the spectral analysis.
EPIMEDOKOREANONE A FROM THE AERIAL PARTS OF FEPIMEDIUM KOREANUM NAKAI
Wen Kui LI , Jun Shan YANG , Pei Gen XIAO , Jing Qi PAN , Mu Jean LU , Ru Yi ZHANG
1996, 7(1): 23-24
[Abstract](264) [FullText HTML] [PDF 54KB](7)
Abstract:
A new α-pyrone derivative,epimedokoreanone A was isolated from the aerial parts of Epimedium koreanum. Nakai.Its structure was determined by spectroscopic methods (IR,MS,1H NMR,13C NMR,DEPT,1H-13C COSY and 1H-13C long range COSY).
STUDIES ON PHOTOSENSITIZED OXIDATION OF DITERPENOIDS FROM HEDYCHIUM GENUS
Qing ZHAO , Xiao Jiang Hao , Yao Zu Chen , Cheng Zou
1996, 7(1): 25-28
[Abstract](155) [FullText HTML] [PDF 118KB](0)
Abstract:
Several products(2)-(6) were obtained from Hedychenone(1),a furanoid diterpene,by photosensitized oxidation,and the structures were identified by spectral methods.The mechanism of the reaction was discussed.
CONFORMATION ANALYSIS OF GUANOSINE-5'-DIPHOSPHO-FUCOSE
Min Bo CHEN , Yu LIU , Zhong Wu GUO , Ge Qing CAI
1996, 7(1): 29-32
[Abstract](158) [FullText HTML] [PDF 174KB](0)
Abstract:
The conformation analysis of the donor substrate,guanosine-5'-diphospho-fucose(GDP-fucose),via model compound to mimic the complex of GDP-fucose with divalent cation is performed by means of molecular dynamics,energy minimization and grid scan technique.
ELECTROREDUCTION OF OF 6-MERCAPTOPURINE AND ITS ANALYTICAL APPLICATION
Hui Zhi FAN , Xiang Ke KONG , Hua YAN , Jing Hao PAN
1996, 7(1): 33-34
[Abstract](267) [FullText HTML] [PDF 120KB](0)
Abstract:
The polarographic and voltammetric behavior of 6-mercaptopurine were studied by several electrochemical techniques.There are two reduction peaks in HAc-NaAc buffer solution at pH 4.0.The characteristics of the second peak (P2) were studied in detail.The relationship between P2 current (ip2) and concentration of 6-mercaptopurine is linear in the range of 1×10-7~1×10-4mol/L.It has been applied to quantitative analysis of an anticancer tablet with satisfying results.The mechaniam of the electrode reaction was proposed also.
ON-COLUMN ELECTRO-PUMPING SYSTEM FOR SAMPLE INTRODUCTION IN CAPILLARY ELECTROPHORESIS
Qi Shan LIN , Ting Ting ZHANG , Guo Quan LIU
1996, 7(1): 35-38
[Abstract](255) [FullText HTML] [PDF 182KB](0)
Abstract:
The design of a simple and reproducible sample injection system for capillary electrophoresis is described in the present work.In this system,two capillaries are coupled together with a section of controlled porous glass (CPG). When the oncolumn CPG section is immersed in a buffer reservoir along with an electrode to allow a potential to be applied across just one capillary,the Strang electroosmotie flow generated in this capillary serves to pull the analyte into the other capillary.With this sample introduction system,the RSD for peak height over 20 runs was ca.2.8%.
LASER INDUCED FLUORESCENCE DETECTOR(LIF) FOR CAPILLARY ELECTROPHORESIS
Ming Sheng MA , Hui Wan HAN , Guo Quan LIU
1996, 7(1): 39-42
[Abstract](154) [FullText HTML] [PDF 211KB](0)
Abstract:
A highly sensitive laser induced fluorescence detector for capillary electrophoresis is described.With an argon laser at 488 nm for excitation,the emitted light was collected by an optical fiber and measured by a PMT.Various elements that affected the sensitivity of the detector were discussed in detail.The detection limit for fluorescein was 5.4 amole.
NICKEL PHTHALOCYANINE-SURFACTANT DDAB FILM ELECTRODE FOR ELECTROCHEMICAL CATALYSIS
Nai Fei HU , Tinq LIU , Yong Huai ZENC
1996, 7(1): 43-46
[Abstract](172) [FullText HTML] [PDF 151KB](0)
Abstract:
Voltammetric properties of didodecyldimethylammonium bromide (DDAB) films containing nickel phthalocyanine (NiPc) were examined.NiPc-DDAB film electrode shows stable voltammetric response in KBr water solution and can catalyze reductions of halogenated acetic acids.The reduction potentials for all substrates studied shifted positive by 0.4-0.6 V.
ELECTRON TRANSFER AGENT DEPENDENCY OF MONOOXYGENATION OF CYCLOHEXANE CATALYZED BY SILICA IMMOBILIZED N,N'-BIS[2-(BENZIMIDAZOLYLMETHYL)] AMINO FERROUS ACETATE COMPLEX
Tie Jun WANG , Zhao Hui MA , Mei Yu HUANG , Ying Yan JIANG
1996, 7(1): 47-50
[Abstract](222) [FullText HTML] [PDF 142KB](0)
Abstract:
Silica immobilized N,N'-bis[-2-(benzimidazolylmethyl)]amino-ferrous acetate complexes (Ⅳ) catalyzed monooxygenation of cyclohexane to cyclohexanol with the turnover number 8.4 (equivalent C%=11.2) under mild conditions.The methylene blue is the most effective electron transfer agent which can also regulate products distribution.The iron content of the polymer-supported complexes,the redox potentials and the concentration of methylene blue greatly affect the activity and selectivity of the complex (Ⅳ).
THE DISSOCIATION CONSTANT OF ARACHIDIC ACID BY IR AND LB TECHNIQUES
Chang Yu FAN , Tie Feng CHEN , Long JUNG
1996, 7(1): 51-54
[Abstract](163) [FullText HTML] [PDF 145KB](0)
Abstract:
The dissociation constant of arachidic acid on a subphase containing Ag+ ion was measured by IR and LB techniques.
HYBRID ZINC(Ⅱ) AND IRON(Ⅲ)PORPHYRIN DIMER:A NEW MODEL SYSTEM OF CYTOCHROME P450 TO HYDROXYLATE CYCLOHEXANE
Zhan Liang LIU , Jin Wang HUANO , Cai Lin LAO , Liang Nian JI
1996, 7(1): 55-58
[Abstract](167) [FullText HTML] [PDF 138KB](0)
Abstract:
Hybrid zinc(Ⅱ) and iron(Ⅲ) porphyrin dimer,linked with a short flexible hydrocarbon chain(Fig.1),has been synthesized and characterized by EA,IR,1H-NMR,XPS,and EPR spectroscopy.As a new model system of cytochrome P450,hybrid zinc(Ⅱ) and iron(Ⅲ) porphyrin dimer like iron(Ⅲ) porphyrin effectively catalyze hydroxylation of cyclohexane with molecular oxygen under mild conditions and catalytic activities of dimer are higher than those of iron(Ⅲ) porphyrin.Factors affecting catalytic activities are discussed from the point of view of partial intramolecular redox.
AB INITIO STUDY OF 1,2-DITHIOSQUARIC ACID
Li Xin ZHOU , Jing Lai ZHANG , An Min TIAN , Guo Sen YAN
1996, 7(1): 59-62
[Abstract](169) [FullText HTML] [PDF 157KB](0)
Abstract:
Results of ab initio SCF calculation of 1,2-dithiosquaric acid (3,4-dihydroxy-3-cyclobutene-1,2-dithione) are reported.The ZZ isomer is found to be the most stable of the three isomers.An isodesmic energy analysis has been carried out at the HF 6-31G'//6-31G' level for the three planar isomers.The three isomers have positive isodesmic energies or small negative ones,suggesting that 1,2-dithiosquaric acid is not aromatic.Vibrational frequencies have also been calculated for the three isomers.
SIMULATION OF THE THERMODYNAMIC QUANTITIES OF SELF-AVOIDING WALK CHAIN
De Lu ZHAO , Xue Dong ZHOU , Yun HUANG
1996, 7(1): 63-66
[Abstract](158) [FullText HTML] [PDF 140KB](0)
Abstract:
A Monte Carlo method has been proposed for direct simulating the thermodynamic quantities of a single self-avoiding walk chain with the neighbour interaction on a simple cubic lattice.The simulation data of me conformational entropy of me chain length 16 have been found to be consistent very well with the exact results obtained by the direct counting method.
ESCA STUDY OF DICHLOROZIRCONOCENE/METHYLALUMINOXANE OLEFIN POLYMERIZATION CATALYST SYSTEM
Jun TLAN , Bao Tong HUANG
1996, 7(1): 67-70
[Abstract](165) [FullText HTML] [PDF 149KB](0)
Abstract:
An investigation has been undertaken by use of ESCA in the characterization of the central metal(Zr) of dichlorozirconocene/methylaluminoxane homogeneous olefin polymerization catalyst.The change of electron density shown by a shift in ESCA signals (181.8→182.7eV) indicates that the catalytic species are "cation-like".Within the range of detecting sensitivity of ESCA spectrometer,only a part of the new catalytic derivative was formed.The influence of complexion time and Al:Zr ratio on the formation of the catalytic zirconocene cation has also been investigated.
SYNTHESIS OF LINEAR CONJUGATED POLYBENZONITRILE WITH ULTRAFAST OPTICAL KERR EFFECT
Xiong Yan ZHAO , Qing XU , Yuan Kang HE , Huo Ying CHEN , Di QIANG , Cong Fang WANG , Xi Cheng Al , Zong Ju XIA , Ying Hua ZOU
1996, 7(1): 71-72
[Abstract](161) [FullText HTML] [PDF 103KB](0)
Abstract:
Linear poiybenzonitrile with carbon-nitrogen conjugated backbones was prepared by piasma polymerization techniques.The ultrafast Kerr effect of polymer in DMF solution was examined with femtosecond laser pulses.Second order hyperpolarizability varied with polymerization degrees.
EFFECT OF ANNEALING ON MICROSTRUCTURE OF AROMATIC LIQUID CRYSTALLINE COPOLYESTERS
Yong WANG , Da Cheng WU , Rui Xia LI
1996, 7(1): 73-74
[Abstract](165) [FullText HTML] [PDF 83KB](3)
Abstract:
The effects of thermal treatment on microstructure of the polyesters were studied.Annealing below Tc-n,physical diffusion processes dominate to yield an increasing crystallinity along with increased molecular weight,transesterification reactions are limited to the end groups and the microstructure had not changed.Annealing near Tc-n,chemical processes dominate and simultaneously make the microdomains ordered more perfectly.Analysis by 13C NMR proved that interchain transesterification had occurred.
THE CONDUCTIVITY BEHAVIOR OF A POLYMER GEL ELECTROLYTE
Xiao Guang SUN , Yun Qing LIN , Li Ming DING , Bin LI , Xia Bin JING
1996, 7(1): 75-76
[Abstract](171) [FullText HTML] [PDF 109KB](0)
Abstract:
A new kind of polymer gel electrolyte which is composed of polytriethylene glycol dimethacrylate(PTREGD),propylene carbonate(PC) and LiPF6 has been prepared by thermal polymerization.The conductivity was measured as a function of temperature,and it was found that the Arrhenius equation was held very well through out the salt concentration studied.Maximum room temperature conductivity of 4.95×10-4S/cm,as well as a minimum activation energy value of 18.90 kJ/mol were obtained at the same salt concentration of 0.22 mol/L.
ROLE OF PARTICLE SIZE OF NANOMETER GOLD ON THE ENZYMEME MBRANE RESPONSIBILITY
Lin ZHANG , Chang Yu FAN , Long JIANG
1996, 7(1): 77-80
[Abstract](162) [FullText HTML] [PDF 160KB](0)
Abstract:
The influence of different size of gold nanometer particles (1Onm,20nm,30-40nm) on the glucose oxidase enzyme electrode response has been investigated by using a sol-gel method which is simple and easy to study this phenomena quantitatively.The response electric current was increased with the increase of the ratio of gold to GOD.The mechanism of this effect has been discussed.
ELECTROCHEMICAL BEHAVIOR OF MOLYBDOTUNGSATE HETEROPOLY COMPLEX WITH NEODYMIUMK10H3[Nd(SiMO7W4O39)2]xH20 IN AQUEOUS SOLUTION
Xiu Mei ZHANG , Long CHENG , Xian Dan XI , Bai Feng LIU , Shao Jun Dong
1996, 7(1): 81-84
[Abstract](240) [FullText HTML] [PDF 180KB](0)
Abstract:
The voltammetric behavior of the titled compound (denoted as Nd (SiMo7W4)213-) in aqueous solution had been studied.An unusual pH response was discussed.The adsorption of the anion on the dropping mercury electrode and a selfinhibition influence of the adsorbed anions on the redox process of those anions dissolved in solution were found.The electrocatalytic effects of the anion on the bromate reduction were investigated.
APPLICATION OF CITRATE COMPLEXES TO SYNTHESIS OF INORGANIC OXIDES VIA MICROWAVE IRRADIATION
Jia Qiang WANG , Pin Jie HONG , De Bin ZONG , Shu Shan DAI
1996, 7(1): 85-86
[Abstract](157) [FullText HTML] [PDF 61KB](0)
Abstract:
LaMnO3,LaFeO3 and La2NiO4 were synthesized with citrate complexes via microwave irradiation.
SYNTHESIS AND CRYSTAL STRUCTURE FOR PALLADIUM(Ⅱ) DITHIOCARBIMATO COMPLEX
Jie Ying WU , Yu Pang TIAN , Hoong Kun FUN , Boon Chuan YIP
1996, 7(1): 87-88
[Abstract](239) [FullText HTML] [PDF 92KB](0)
Abstract:
The title complex crystallized in space group P21/c with Z=2 in a unit cell of dimensions,a=9.811(1)Å,b=16.851(2)Å,c=15.855(3)Å;β=98.71(1)°, v=2591.0(6)Å3, Dc=1.225gcm-3,F(000)=1024,μ=0.55mm-1,R=0.0338,Rw=0.0631.The geometry of the Pd(Ⅱ)complex is square-planar configuration. The S2C=NPhNH2 group coordinated as asymmetric bidentate ligand forming a stable four member ring by chelation through the two sulphur atoms.
SYNTHESIS, CHARACTERIZATION OF 2-[2-(3-NITRO-4-METHOXYLPHENYL)VINYL]-l-METHYLPYRIDINIUM PENTA AND HEXANITRATO RARE EARTH(IU) COMPLEXES
Huan Wang JING , Zi Jie HOU , Shu Ying CHEN , Du LI
1996, 7(1): 89-90
[Abstract](172) [FullText HTML] [PDF 116KB](0)
Abstract:
The title complexes have been synthesized by the reaction of rare earth nitrate with 2-[2-(3-nitro-4-methoxylphenyl)vinyl]-1-methylpyridinium nitrate in ethanol solution and have been characterized by IR,UV and 1H NMR spectra,TG-DTA,molar conductance and X-ray powder diffraction.The results show that the crystal form of Nd complex containing one molecular water as a ligand is eleven coordinated and is different from the others.
SYNTHESIS AND CHARACTERIZATION OF (PPh3)3Co(μ-CO)2 V(CO)2Cp AND (PPh3)HPt(μ-CO)(μ-PPh2)V(CO)2Cp
Chang Ping SHAO
1996, 7(1): 91-92
[Abstract](161) [FullText HTML] [PDF 86KB](0)
Abstract:
The heterobinuclear metal carbonyl complexes (PPh3)3Co(μ-CO)2V(CO)2 Cp and (PPh3) HPt(μ-CO) (μ-PPh2) V(CO)2 Cp were synthesized and characterized by elemental analyses,IR and NMR spectroscopic means.
STUDY ON THE UCST AND LCST IN PHB/PBHE-SOLVENT SYSTEM
Hong Fang ZHANG , Jing Yu LIU , Shang Er WANG , Fa Jiang SONG , Zhi Shen MO
1996, 7(1): 93-94
[Abstract](148) [FullText HTML] [PDF 63KB](0)
Abstract:
Upper and lower critical solution temperature (UCST and LCST) behaviours have been examined for solution of PHB/PBHE blends in chloroform and chlorobenzene.Polymer-Solvent systems prepared with various solvents and concentrations were found to possess UCST and LCST characteristics.PHB/PBHE solution in chloroform displayed greater miscibility temperature region than that of the blend in chlorobenzene,but the relative tendency of both UCST and LCST were similar.
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