Loading...
CJCU

Table of Content

    24 July 1996, Volume 17 Issue 7
    Previous Issue    Next Issue
    Articles
    Syntheses and Crystal Structures of Two Mononuclear Complexes M(2-SC5H3NH-3-SiMe3)2Cl2(M=Cd,Zn)
    JIN Xiang-Lin, TANG Ka-Luo, JIA Shao-Juan, TANG You-Qi
    1996, 17(7):  999-1003. 
    Asbtract ( )   PDF (336KB) ( )  
    Related Articles | Metrics
    The title complexes,M(2-SC5H3NH-3-SiMe3)2Cl2(M=Cd(1),Zn(2)),were synthesized through the reaction of CdCl2·2.5H2O(or ZnCl2) with 3-(trimethylsilyl)-pyridine-2-thiol(TSPT)in methanol,They were characterized by X-ray diffraction analysis,The crystal of compound 1 belongs to the orthorhombic system,with space group Pna21,a=2.1472(4)nm,b=1.4453(3)nm,c=0,8049(2)nm,V=2.4980(9)nm3,Dc=1,4629/cm3,Z=4.The final Ris 0.0354 for 1602 reflections[F>4.0σ(F)].The crystal of complex 2 belongs to the orthorhombic system, with space group Fdd2,a=1.7563(4)nm,b=2.9454(6)nm,c=0.9224(2)nm,V=4.772(2) nm3,Dc=1.400 g/cm3,Z=8.The final Ris 0.0237 for 1669 reflections [F>4.0σ(F)].In the two mononuclear complexes, themetal atom is coordinated with two Cl atoms and two Satoms from the sterically hindered thiolate ligands.
    Studies on Tetraaza[14]Annulene Nickel(Ⅱ)Complexes(Ⅱ)──Syntheses and Electrochemical Properties or Substituted Tctraaza [14]Annulene Nlckel(Ⅲ) Complexes
    LI Dong-Wen, ZHANG Wen-Wei, XU Er-Jie, MENG Qing-Jin, YOU Xiao-Zeng
    1996, 17(7):  1004-1009. 
    Asbtract ( )   PDF (414KB) ( )  
    Related Articles | Metrics
    Aseries of tetraaza [14] annulene nickel(Ⅱ)macrocycles,which have cis-and trans-isomers,were synthesized for the first time by the reaction of template effect and electrophilic substitution.All of them have been characterized via EA,IR,UV.1H NMRand MS.Especially the data of 1H NMRspectra demonstrate that the two isomers really exist.In addition,the electrochemical behavior of the above compounds,together with another series of tetraaza[14]annulene nickel(Ⅱ)complexes,have been studied.We draw the conclusions of the CVpeaks by using the transient and ESRelectrochelnical methods, discussed the mechanism of forming films on the electrode surface by electropolymerization.
    Synthesis and DNA-binding Studies of Ruthenium Mixed-polypyridyl Complexes
    WU Jian-Zhong, WANG Lei, YANG Guang, ZENG Tian-Xian, JI Liang-Nian
    1996, 17(7):  1010-1015. 
    Asbtract ( )   PDF (589KB) ( )  
    Related Articles | Metrics
    Two new ligands,imidazo[f],10-phenanthroline(IP)and 2-phenylimidazo[f]1,10-phenanthroline(PIP),and four new complexes,[Ru (bpy)2(IP)]2+(b2IP),[Ru (bpy)2(PIP)]2+(b2PIP),[Ru(phen)2(IP)]2+(p2IP)and[Ru(phen)2(PIP)]2+(p2PIP)were synthesized and characterized.The binding of the complexes to calf thymus DNAwas investigated by using electronic absorption,steady-state luminescence and circular dichroism spectra.The order of total binding affinities was found to be b2IP<b2PIP≤p2IP<p2PIP,consistent with the order of the ligands'planarities,π-electron extension and hydrophobicities,bpy《phen
    Synthesis,Fluorescence Charactcteristics and Langmuir-blodgett Film of a Green Strongly Fluorescent Terbium isobutyryl Pyrazolonee Complex
    LI Qin, ZHOU De-Jian, YAO Guang-Qing, HUANG Chun-Hui, Umetani Shigeo, Matsui Masakazu
    1996, 17(7):  1016-1018. 
    Asbtract ( )   PDF (227KB) ( )  
    Related Articles | Metrics
    Agreen strongly luminescent amphiphilic lanthanide complex:N-hexadecyl pyridinium tetrakis(1-phenyl-3-methyl-4-isobutyryl-pyrazolone-5)terbium was prepared and identified by elementary analysis.The Langmuir film on the air/water interface and the transfer of the Langmuir film to form LBfilms by conventional vertical dipping method were investigated.The fluorescence spectra and fluorescence lifetime of the complex at solid state,in CHCl3 solution and on the ordered LBfilm were studied.The results show that the title complex exhibits a good performance in both fluorescence and film formation and transformation,This provides valuable fundamental data for its further application in microcavity laseroscillators.
    The Synthesis,Structure and Characterization of V2O6·H3NCH2NH3
    XU Jia-Ning, YANG Guo-Yu, WANG De-Jun, MA Wen-Ying, SUN Hao-Ran, XU Ji-Qing, HUANG Xiao-Ying
    1996, 17(7):  1019-1021. 
    Asbtract ( )   PDF (2350KB) ( )  
    Related Articles | Metrics
    A metavanadate in coffe colour,V2O6·H3NCH2CH2NH3,was synthesized by hydrothermal method and its crystal structure was determined by single crystal X-ray diffrac tion,Crystal data:monoclinic, space group P21/c,a=0.5529(2) nm,b=1.2900(7) nm,c=0.5683(2) nm,β=97.57(3)°,V=0.4018(3) nm3,F(000)=260,Dc=2.15 g·cm-3,Z=2,R=0.041,Rw=0.052.The structure is based on VO4 tetrahedra sharing two vertex to form a single type of chain running along the c axis.The hydrogen bond(O…H N)be tween (VO3-)∞ chains and H3NCH2CH2NH32+ was formed.IR spectrum confirmed that the ethylenediamine is protonated.The analysis of DRS and SPS are given.
    Synthesis of Lanthanide Porphrin Coordination Compounds by Solid State Reaction
    LIU Guo-Fa, TENG Yong-Fu, SHI Tong-Shun
    1996, 17(7):  1022-1024. 
    Asbtract ( )   PDF (227KB) ( )  
    Related Articles | Metrics
    Synthesis of lanthanide porphyrin coordination compounds was described.The coordination compounds contain acetylacetonate-5,10,15,20-tetraphenylporphyrin ybtterbium,acetylacetonate-5.(p-hydroxyphenyl)-10,15,20-tri(p-methoxyphenyl) porphyrin lutetium acetylacetonate-5,10,15,20(p-methoxyphenyl) porphyrin europium and acetylacetonate5,10,15,20-(p-naphthyl)-tetra-benzoporphyrin erbium,The coordination compounds were characterized by elementary analysis, UV-Vis,IRspectra and 1H NMRspectra.
    Kinetic Studies of Immunogobulin M Immunoreaction Using Quartz Crystal Microbalance Methodology
    CHU Xia, LIN Zhao-Hui, SHEN Guo-Li, YU Ru-Qin
    1996, 17(7):  1025-1029. 
    Asbtract ( )   PDF (2621KB) ( )  
    Related Articles | Metrics
    The adsorption and desorption of Immunogobulin M(IgM) antigen on the ecrystal modified with anti-IgMantibody have been continuously monitored and the immunoreaction kinetics of IgM-antigen with the anti-IgMantibody has been investigated by using the quartzcrystal microbalance methodology.Immobilization of the anti-IgMantibody to the crystal's surface was accomplished via a CNBr-activated copolymer coating of hydroxyethyl-methacrylate(HEMA) and methyl-methacrylate (MMA),The results indicated that the binding behavior of IgMon the crystal's surface was fitted for the Langmuir adsorption equation quite well.The association constant of the immunoreaction(Kass)calculated from this equation was7.10×107(mol/L)-1.The kinetic equation of this reaction under the condition of excessive IgM antigen was derived.This equation was exactly fitted for the experimental results.The reaction rate constants (kf) at different temperatures and the Arrhenius activation energy(Ea) of the immunoreaction in this experimental system were calculated.It was inferred that the activation energy of this immunoreaction was mainly used to overcome the hydrousenergy of the molecules of antigen and antibody.
    A Novel Method for Resolution of Completely Overlapping HPLC-UV Two-dimensional Peaks
    LI Tong-Hua, CONG Pei-Sheng, ZHAO Kai, NI Ya-Ming, JI Jian-Guo, CHEN Jun
    1996, 17(7):  1030-1034. 
    Asbtract ( )   PDF (2552KB) ( )  
    Related Articles | Metrics
    Anovel method for resolution of completely overlapping HPLC-UVtwo-dimensional peaks is developed in this paper,For two-dimensional mensured data of two-component mixture,the pure spectra can be obtained if there is a single component region in the completely overlapping region and the spectra are linearly independent.The determination ofpure spectra is equivalent to an optimizing problem,The numeric genetic algorithm is used to find the optimum solution.The method is carried out to analyze 2,4-dinitrophenol and 3,5-dinitrobenzoic acid and the impurity in tetracyclin hydrochloride.
    Studies on the Label of Antibody by a New Reagent N-(β-Carboxypropionyl)isoluminol
    WANG Qiong-E, ZHUANG Hui-Sheng, ZHANG Fan
    1996, 17(7):  1035-1038. 
    Asbtract ( )   PDF (348KB) ( )  
    Related Articles | Metrics
    Anew reagent N-(β-carboxypropionyl)isoluminol (CPIL)is used to label sheep anti-human IgG(SaHIgG).The labeled antibody was stable and could be detected at least down to 10-13mol/L,The molar incorporation ratio is estimated to be 0.28 mol of CPILper mol of SaHIgG.There are no apparent changes in the immunoreactivity of the labeled SaHIgGand in the quantum efficiency of the CPILattached to the protein.
    Theoretical Investigation on the New Type Two-dimensional Packed-capillary Column GC System(Ⅱ)──Effect of Column Conditions on Column Efficiency
    ZHANG Wei-Bing, XU Guo-Wang, ZHANG Yu-Kui, SHI Jing-Jiang, LU Pei-Zhang
    1996, 17(7):  1039-1043. 
    Asbtract ( )   PDF (426KB) ( )  
    Related Articles | Metrics
    The rules that the column conditions affect column effciency are investigated by chromatographic dynamics in this paper,It is further proved that the higher precolumn temperature and the faster precolumn carrier gas is beneficial to the column efficiency of the system of long capillary with small packed column,Considering the main column conditions and split ratio,it was also proved theoretically and experimentally that the proper main column temperature,carrier gas speed and the larger split ratio is profitable to improving the column efficiency in two-dimensional GCsystem.
    N-Hydroxysuccinimidyl-α-naphthylacetate as Pre-cloumn Derlvating Reagent to Scperate and Determine Peptides and Their Hydrolysates by Reversed Phase HPLC
    ZHAO Yuan-Yuan, XU Guo-Liang, ZHANG Hua-Shan, LI Jun
    1996, 17(7):  1044-1047. 
    Asbtract ( )   PDF (286KB) ( )  
    Related Articles | Metrics
    Using N-hydroxysuccinimidyl-α-naphthylacetate(SINA,synthesized by ourselves) as pre-column derivating reagent,glutathion,diglxcyl-glycine,glycyl glycine, Glu,(Cys)2 and Gly were separated and determined by reversed phase high performance liquid chromatograph (RP-HPLC).The six derivatives were eluted within 16min with a mobile phase of methanol-acetic ether-water(17/3/80 ,volume ratio)containing 15 mmol/L pH=5.4 acetate buffer on C18 column,At the ratio of signal to noise S/N=3,the detection limit is in lower picornole range,The reproducibility was good.
    A New Kinetic Equation on Luminescent Quenching
    RUAN Fu-Chang, LI Xiang-Ming, MO Bing-Lu, GONG Guo-Qing, DENG Song-Jiu
    1996, 17(7):  1048-1051. 
    Asbtract ( )   PDF (373KB) ( )  
    Related Articles | Metrics
    According to the kinetic model of optical chemical reactions,a new kinetic equation is deduced as the following: I0/I=1+APQB As a simple and prastical kinetic equation, it can be used to determine quantitatively a gasous or liquid quencher quenching a luminescent complex immobilized in some polymer matrix.The experimental results show that the equation can be fitted with the luminescentquenching data and be used to explain the common mechanism of luminescent quenching reactions in a polymer matrix very well.
    Equation of Voltammetric Waves Controlled by Diffusion,Charge Transfer and Chemical Reactions at Ultramicroband Electrode
    JIN Bao-Kang, SHI Han-Sheng, ZHANG Zu-Xun
    1996, 17(7):  1052-1055. 
    Asbtract ( )   PDF (2384KB) ( )  
    Related Articles | Metrics
    The theory of electrochemical processes controlled by diffusion,chemical reaction and electrode reaction occurring at ultramicroband electrodes are investigated by means of integral transformations.Multidimensional integral equations related to the Eqcirr,Eqcirr and crev Eq coupled with quasi-reversible charge transfer are obtained,the results we obtained as follows:For EqCirr process:   where f(t,x) is the dimensionless electroactive species flux on electrode surface.The voltammogram can be calculated by numerical method,and the typical i-E curves are shown in this paper.
    Studies on the Cocolouration Effect in Scandium-Rare Earth p-acetylchlorophosphonazo System
    LIU Shuang-Cheng, XU Zhong-Jun, PAN Jiao-Mai
    1996, 17(7):  1056-1058. 
    Asbtract ( )   PDF (2387KB) ( )  
    Related Articles | Metrics
    Scandium forms a β-type complex with p-acetylchlorophosphonazo(CPApA)in acidic medium.In the presence of cerium,a cocolouration effect was observed due to the formation of a mixed polynuclei complex[Sc-Ce-(CPApA)2].In this paper,the transformation reaction between α-complex of scandium-CPApAand β-complex was studied kinetically and the mechanism of the formation of the ternary complex was discussed.Finally,the cocolouration effect of scandium on RE-CPApAsystem has also been discussed.
    Capillary Zone Electrophoresis Separation of Basic Proteins Using Arginine and Lysine as Buffer Additives
    REN Ji-Cun, DENG Yan-Zhuo, CHENG Jie-Ke
    1996, 17(7):  1059-1061. 
    Asbtract ( )   PDF (223KB) ( )  
    Related Articles | Metrics
    The separation of basic proteins by capillary electrophoresis was plagued by the adsorption of the basic proteins onto the capillary inner surface,Atnethod is presented to solve this problem by using arginine and lysine as buffer additives,It was found that in the neutral or slightly alkaline solution, arginine and lysine can be adsorbed onto the inner surface of capillary to reduce the electroosmotic flow and the adsorption of the proteins efficiently, which results in improvement of resolution efficiency and reproducibility of the migration time and peak height of basic proteins,The experimental results show that arginine and lysine are the efficient buffer additives used in separation of basic proteins.
    Studies on the Coupling Technique Between High Performance Capillary Electrophoresis and Charge-coupled Device Detector(Ⅶ)──Separation of Some Oligopeptides and Their Degradation Products
    XIONG Shao-Xiang, LI Jian-Jun, CHENG Jie-Ke
    1996, 17(7):  1062-1064. 
    Asbtract ( )   PDF (244KB) ( )  
    Related Articles | Metrics
    A capillary electrophoretic setup with laser-induced fluorescence detection using charge-coupled device detector was used to separate three kinds of oligopeptides and their degradation products.By the use of fluorecein isothiocyanate to derive analytes,the operation conditions were investigated in detail.The six components were separated within 14min.
    Synthesis and Structure of Complex E(η5-Me3SiC5H3)2[Fe(CO)]2(μ-CO)2
    XU Shan-Sheng, XIE Wen-Hua, ZHOU Xiu-Zhong, WANG Jin-Ling, CHEN Hong-Li, GUO Hong-sheng, MIAO Fang-Ming
    1996, 17(7):  1065-1069. 
    Asbtract ( )   PDF (2481KB) ( )  
    Related Articles | Metrics
    Complexes E(η5-Me3SiC5H3)2 [Fe(CO)]2(μ-CO)2[E=Me2Si(1),Me2SiOSiMe2(2)] were obtained by reaction of bridged compounds E(Me3SiC5H4)2[E=Me2Si(Ⅰ),Me2SiOSiMe2(Ⅱ)]with Fe(CO)5 in refluxing xylene.Compounds 1,2 were revealed to be cis-isomers by 1H NMRspectra and X-ray diffraction analysis.Extensive desilylation was observed.Crystals of 1 and 2 are monoclinic, belonging to space-group P21/m.1:a=0.7359(3)nm,b=1.9409(1)nm,c=0.9383(5)nm,β=99.71(4)°,V=1.32010(1) nm3,Z= 2,Dc=1.394 g/mL;2:α=0.6743(5)nm,b=2.2635(5)nm,c=1.0802(1) nm,β= 108.1(2)°,V=1.5668(2)nm3 Z=2,Dc=1.493 g/mL.
    Studies on Heteromacrocyclic Polyether(ⅪⅤ)──The Synthesis of Selenacrown Ethers with Hydroxy Group and Their Palladium Complex
    WU Jun, LIU Xiu-Fang, XU Han-Sheng
    1996, 17(7):  1070-1073. 
    Asbtract ( )   PDF (378KB) ( )  
    Related Articles | Metrics
    In alkaline condition,4-hydroxy-1,2-diselenacyclopentane(1)was reduced by potassium borohydride into diselenolate,then condensed with dihalides or diol ditosylate;seven diselenacrown ethers with hydroxy group(2a─8a) and four tetraselenacrown ethers with hydroxy group(2b─4b, 6b)were obtained.At the same time,the palladium compounds of crown ether 4a and 4b were prepared by reacting 4a and 4b with palladium dichloride.Their complexing characteristic was discussed.
    Photochemistry of Nonconjugated Bichromophoric Systems (Ⅱ)──Photocyclization Reaction and Fluorescence Spectra Studies of Long Chain Biscoumarins
    DU Da-Ming, WANG Yong-Mei, MENG Ji-Ben, ZHOU Xiu-Zhong, WANG Guo-Chang, LIANG Li-Jun, GAO Huan
    1996, 17(7):  1074-1077. 
    Asbtract ( )   PDF (391KB) ( )  
    Related Articles | Metrics
    Aseries of polymethylene bis(4-methyl-7-coumarinyl)oxyacetates have been synthesized and their photochemical reaction and fluorescence spectra have been studied.It was found that only intramolecular photocyclization products were obtained when polymethylene bis(4-methyl-7-coumarinyl)oxyacetates were directly irradiated in chloroform.The yields of the products decreased with the increase of methylene chain lengths, and this result accords with the phenomena found in the fluorescence spectra,i.e.,the relative fluorescence intensity increased with the increase of methylene chain length.
    Studies on the Synthesis of Fluorinated C-Nucleosides──Synthesis of N-Alkyl 3-(4'-deoxy-4'-fluoro-β-L-arabinopyranosyl)-1,2,4-oxadiazole-5-carboxamides
    CHENG Hua, MA Ling-Tai, ZHANG Li-He
    1996, 17(7):  1078-1082. 
    Asbtract ( )   PDF (470KB) ( )  
    Related Articles | Metrics
    N-Alkyl-3-(4'-deoxy-4'-fluoro-β-L-arabinopyranosyl)-1,2,4-oxadiazole-5-carboxamids were synthesized from the corresponding N-alkl 3-β-D-xylopyranosyl-1,2,4-oxadiazole-5-carboxamides which were selectively fluorinated at 4'-position of sugar moiety with diethylaminosulfur trifluoride(DAST).The configuration and conformation of these new Cnucleoside derivatives were identified by 1H NMR,13C NMR,19F NMR,1HH-1HH COSY and MS.
    Synthesis of Diphenylalkylphosphine-boranes
    YANG Wen-Qian, HUANG Tian-Bao, LIU Ling-Fei, HE Liang-Nian, ZHANG Jing-Ling
    1996, 17(7):  1083-1085. 
    Asbtract ( )   PDF (305KB) ( )  
    Related Articles | Metrics
    Anew and facile method for the preparation of diphenylalkylphosphine-boranes 2 was described.Treatment of the available triphenyl phosphine-borane 1 with Na under room temperature,then with propriate alkyl halides below-10℃ afforded seven 2 in good yield,and they were characterized by IR,31P NMR,1H NMRand microanalysis,partially by MS.
    Studies on the Conformation of 2,3,4-Tribenzoyl-1-β-cyano-D-xylopyranose
    ZHANG Liang-Ren, ZHANG Li-He
    1996, 17(7):  1086-1088. 
    Asbtract ( )   PDF (318KB) ( )  
    Related Articles | Metrics
    The conformation of 2,3,4-tribenzoyl-1-β-cyano-D-xylopyranose was studied by using molecular modeling.Molecular dynamic calculation revealed that there was a relative high energy barrier between the chair conformations(Ⅰ) and (Ⅱ).Through the combination of molecular mechanics,molecular dynamics and MNDOcalculations,a relative low energy conformation,i.e.,a chair conformation with the large benzoyl group in axial position,was obtained.The calculated result was in accordance with the NMRexperimental data.
    Synthesis and Bioactivity of 1,3,5-Substituted Pyrazol-4-methylene Cyclopropane Carboxylate
    HUANG Run-Qiu, SONG Jian, FENG Lei
    1996, 17(7):  1089-1091. 
    Asbtract ( )   PDF (2317KB) ( )  
    Related Articles | Metrics
    The title compounds were synthesized by the esterification reaction of 1,3,5-substituted-4-methylol pyrazole with substituted cyclopropane carbonyl chloride,their structure were confirmed by means of 1H NMRand elementary analysis.The bioassay showed that the lethal of 1,2 against mosquito larvae at 1.5×10-7mol/Lwere 100%,The killing activities of 1 and 2 were higher than those of pyrethroid insecticides phenothrin(2×10-6mol/L)and phthalthrin (4×10-6mol/L).The other compounds 3,5,12 showed a higher antiphytoviral activity against TMV(tobacco mosaic virus)compared with DHT(2.4-dioxohexahydro-1,3,5-triazine).
    A Study and Industry Application of Classical Fe-Cu Replacement Reaction
    WU Chen, WANG Jian-Gang, ZHU Yi-Min, LI Dong-Feng
    1996, 17(7):  1092-1095. 
    Asbtract ( )   PDF (282KB) ( )  
    Related Articles | Metrics
    Fe-Cu replacement reaction under different conditions were studied.The composition of the deposits were detected by PESand XRD.The results showed that under the normal condition,the products of the replacement were mainly Cu2O.All the reactions in the system were disscussed.Some side reactions can be restrained by adding accelerator W-1.Under the controlled condition,good copper plate has been achieved.The result is of great importance to copper plating industry.
    Accurate Simulation of Kinetic Process
    ZHANG Zhi-Ying
    1996, 17(7):  1096-1099. 
    Asbtract ( )   PDF (394KB) ( )  
    Related Articles | Metrics
    The kinetic processes of reaction can be accurately simulated by using the weighted least squares method.The weight functions of several kinetic models were derived.The crystallization kinetics of poly(ethylene terephthalate) was analyzed by using the general and the weighted least squares methods, The results of analysis of variance indicate that the standard deviations given by the weighted least squares methods are lower than those given by the general least squares method and the slopes and the intercepts simulated by the two methods are different obviously.The simulated curves of the relative crystallinity and its derivative versus time are illustrated.
    1H and31P NMR Study of the Substituent-effects of α-Oxyalkylphosphonates
    YAN Jiang-Li, HU Li-Ming, LIU Zhao-Jie
    1996, 17(7):  1100-1103. 
    Asbtract ( )   PDF (304KB) ( )  
    Related Articles | Metrics
    1H and 31P NMRspectroscopies were usedto study 21 compounds of O,O-diakylα-(2-benzoxazolyl)oxyacetoxyalkyl-phosphonate.It is indicated that the non-equivalence between the two ester OR′groups is affected by the a-substituentes.The larger the substituent is,the greater the difference of 1H chemical shifts between the two ester OCH3 groups is.The a and ester substituents also affected α-magnetic nuclei, that is α-Hand α-31P.The regular dependences of their chemical shifts, as well as their scalar coupling interaction,on thesubstituents were diseussed in detail.
    A Theoretical Study on the Microcanonical Rate Constants of Unimolecular Rerctions──Calculation of Rate Constants Regarding to the Effect of Curvature and the Selection of Rotation States
    LI Zong-He, WANG Yan, ZHANG Shao-Wen, FENG Wen-Lin, LIU Ruo-Zhuang
    1996, 17(7):  1104-1107. 
    Asbtract ( )   PDF (277KB) ( )  
    Related Articles | Metrics
    The curvature correction factor Ais introduced into the tunneling probability expression derived by W.H.Miller.Then the modification for the microcanonical unimolecular rate constant formula is obtained.The application of the formula to the unimolecular hydrogen transfer reaction of F─C≡C─H indicates that the rate constants have asignificant enhancement in the tunneling region when the factor Ais involved,but the selection of rotation states has little effect on the reaction rate.
    A Theoretical Study on the Addition Reaction of Silylenoid H2SiLiF and Ethylene
    FENG Da-Cheng, FENG Sheng-Yu, DENG Cong-Hao
    1996, 17(7):  1108-1111. 
    Asbtract ( )   PDF (2475KB) ( )  
    Related Articles | Metrics
    The addition reaction of silylenoid H2SiLiF and ethylene,H2SiLiF+C2H4→SiC2H6+LiF,has been studied by using ab initio calculations.The transition state is similar to that of carbenoid′s reaction.The difference of energies between reactants and products corrected by zero-point energies is-2.4kJ/mol(MP2/6-31G*//6-31G*).The thermodynamic and kinetic calculation have been done and the change in thermodynamic functions,equilibrium constants,factor Aand rate constants of the reaction are given in this paper.
    Ab initio Study of P6(D6h)and P12(D6h)
    FENG Jian-Nan, HUANG Xu-Ri, LI Ze-Sheng, SUN Chia-Chung, ZHANG Gang
    1996, 17(7):  1112-1115. 
    Asbtract ( )   PDF (2471KB) ( )  
    Related Articles | Metrics
    Using Gaussian-92 ab initio program, molecule P6(D6h) and cluster P12(D6h)were optimized at 6-31G* basis sets.The calculations of vibrational frequencies were also per formed.The relative energy of 2P6(D6h)→p12(D6h)was obtained,△E=EP12(D6h)-2EP6(D6h)=-1.197eV,Cluster P12(D6h) is more thermochemically stable than molecule P6(D6h).
    Electronic Suructure of P10 Cluster
    HUANG Xu-Ri, FENG Jian-Nan, LI Ze-Sheng, SUN Chia-Chung, ZHANG Gang
    1996, 17(7):  1116-1118. 
    Asbtract ( )   PDF (2336KB) ( )  
    Related Articles | Metrics
    Using Gaussian-94 ab initio program,the three configurations of P10 cluster with C2v, D5h and C3v symmetries are performed with full geometric optimization by choosing 6-31G* basis set.The relative energy values of the three configurations show that cluster P10(C3v) possesses a thermodynamic stability;the energy gaps between HOMOand LUMOshow that cluster P10(C3v)possesses dynamic stability.On the contrary, the LUMO′s energyvalue of cluster P10(D5h) is lower than that of the others.It is easier to obtain electrons to become the negative ion.
    Recent Pfogress in Valence Bond Theory
    MO Yi-Rong, WU Wei, ZHANG Qian-Er
    1996, 17(7):  1119-1126. 
    Asbtract ( )   PDF (640KB) ( )  
    Related Articles | Metrics
    In the present paper a brief review is given of the historical development in valence bond (VB) theory,The mathematical formulation of the symmetric group approach for VBtheory is summarized,and some important approaches to modern valence bond theory,such as the spin-coupled VB (SCVB),generalized VB(GVB),and VBself-consistent-field(VBSCF)approaches are briefly reviewed.Optimization methods for one electron orbitals are discussed:fully optimized overlap-enhanced orbitals (OEOs)would probably yield an excellent VBwave function, even with only a single covalent structure, but would obscure theclassical interpretation,On the other hand,the use of bonded-distorted orbitals (BDOs)provides a clear classical description in terms of an interplay between covalent and ionic structures,Special attention is given to the bonded tableau unitary group approach (BTUGA),a spin-free VBmethod:an effective algorithm for evaluating Hamiltonian andoverlap matrices is presented,and an ab initio nonorthogonal VBcalculation programme is introduced;Furthermore,the BTUGAapplications are extensivelv reviewed,which include resonance energy calculations,discussions of molecular structures, potentical energy surface calculations, discussion of electron transfer in molecules,studies on the excited states,and the influence of orbital hybridization on single bond lengths.
    An ESR Study on ·OH-radical Scavenging Activity of Water-soluble Fullerenols
    ZHU Yan-Shi, SUN Da-Yong, LIU Gui-Zhen, LIU Zi-Yang, ZHAN Rui-Yun, LIU Shu-Ying
    1996, 17(7):  1127-1129. 
    Asbtract ( )   PDF (323KB) ( )  
    Related Articles | Metrics
    Water-soluble polyhydroxylated fullerene derivatives(fullerenol) were synthesized,and their scavenging ability for ·OH-radical was studied by the combination of ESR spectroscopy and spin-trapping technique with phenyl-t-butyl-nitrone.It was found that fullerenols showed an excellent efficiency in eliminating ·OH free radicals generated by UV photolysis of H2O2.At an applied fullerenol concentration of 0.3mg/mL in the final solution,a radical scavenging efficiency of approximate 95% was achieved, revealing the potential use of these compounds as novel potent free radical scavengers in biological systems.
    Photoelectrochemical Behavior of Azobenzene Self-assembled Monolayers on Gold
    WANG Yong-Qiang, WANG Jian, YU Hua-Zhong, CAI Sheng-Min, LIU Zhong-Fan
    1996, 17(7):  1130-1132. 
    Asbtract ( )   PDF (228KB) ( )  
    Related Articles | Metrics
    A novel azobenzene derivative was synthesized and self-assembled into monlayer on gold.The photochromic and electrochemical behavior of thus formed azobenzene SAMs were studied by investigating the different redox properties before or/and after irradiating the film with 350 nm UVlight.In the large scan range(-0.6～+0.5 V),clear-cut electrochemical response of trans-azobenzene/hydrazobenzene was obtained in B-Rbuffer (0.1mol/L NaClO4, pH:2 ), while no discernible faradic response can be observed in a small scan range(-0.3～+0.5 V).However, after 5 min irradiation of UVlight , redox peaks corresponding to cis-azobenzene/hydrazobenzene raised up in the cyclic voltammograrn.Itshould be noted that:(1)The conversion ratio of trans/cis isomerization is very low in thehishly-organized monolayers due to the inhibition of rigid SAMs' structure.(2) The cis-azobenzene is much easier to be reduced than transform, enable the unique"one way hybrid photoelectrochemical cycle" to be available in SAMs as we obtained previously in LB monolayer.
    Studies on the Fusion Heat of Poly(ether ether ketone ketone)Poly(ether biphenyl ether ketone ketone) Copolymers
    NA Hui, WU Zhong-Wen, ZHANG Hong-Fang, Yang Bao-Quan, WANG Shang-Er, MO Zhi-Shen
    1996, 17(7):  1133-1136. 
    Asbtract ( )   PDF (255KB) ( )  
    Related Articles | Metrics
    on the basis of DSCmeasurements,the △Hf0 values of the fusion heat for PEEKK-PEBEKK copolymers with various biphenyl contents were obtained by using thermodynamics statistical theory proposed by Flory and graphical method of the specific volume-fusion heat.The results reveal that △Hf0 values determined by these two methods for PEEKK-PEBEKKcopolymers with various biphenyl content are nearly the same,and that △Hf0 values are closely dependent on biphenyl content.△Hf0 value is minimum at nB=0.35.
    Synthesis and Characterization of an Amphiprotic Highly Branched Polyester Nanoparticle
    MA Rong-Jiu, ZHOU Bo, SHEN Jia-Cong, WU Qi, WU Jia-Hui, CHEN Jin-Huang
    1996, 17(7):  1137-1141. 
    Asbtract ( )   PDF (488KB) ( )  
    Related Articles | Metrics
    The novel amphiprotic highly branched polyester nanoparticles (HBPN) were prepared by a copolymerization(condensation) of pentaerythritol and phthalic anhydride and studied by laser light scattering (LLS) in both of N,N-dimethylformamide(DMF) and buffer solution (pH=12).The results show that the size of HBPN can be controlled basically by the copolymerization time;HBPNis monomolecular dispersion in DMF,unsoluble in water,but can be dissolved and bears negative charges on surface in alkaline solution;a little amount of HBPN aggregated still in pH=12 buffer solution.
    Effect of Heat Treatment on the Parameters of Crystal Structure and Degree of Crystallinity of Poly (aryl-ether-cther-ketone)
    LIU Tian-Xi, ZHANG Hong-Fang, HAN Ping, MO Zhi-Shen, NA Hui, CAO Jun-Kui, WU Zhong-Wen
    1996, 17(7):  1142-1146. 
    Asbtract ( )   PDF (532KB) ( )  
    Related Articles | Metrics
    The variations of unit cell parameters and crystallite size of nine PEEKsamples treated at various temperatures have been studied by using Wide-Angle X-ray Diffraction(WAXD)The resu lts indicate a decrease in unit cell parameter a,b and c but an increase in crystallite size Lhkl with the increase heat treatment temperature.Based on X-ray scattering intensity theory and using the graphic multipeak resolution method,the formula of degree of crystallinity (Wc,X) for PEEK is derived.The results calculated are compatible with the density measurement and calorimetry.
    Immobilization of E. Coli L-Asparaginase on Chitosan Microsphere
    QIAN Guo-Qiang, ZHOU Ju-Yan, MA Jian-Biao, WANG Dao-Bin, HE Bing-Lin
    1996, 17(7):  1147-1150. 
    Asbtract ( )   PDF (1477KB) ( )  
    Related Articles | Metrics
    E.coli L-asparaginase was immobilized on chitosan microspheres,The synthesis conditions of chitosan microspheres and the properties of immobilized enzyme were discussed.The results showed that the matrix can adsorb L-asparaginase and recover high enzymic activity,The immobilize enzyme was more stable against trypsin than native enzyme.
    The Reaction C60 with Living Anionic Polystyrene Species
    WANG Chang-Chun, PANB Bao-Rong, FU Shou-Kuan
    1996, 17(7):  1151-1153. 
    Asbtract ( )   PDF (228KB) ( )  
    Related Articles | Metrics
    Anovel method is adopted to synthesize a new type of polymeric C60 derivatives,in which C60 sites in the main chain of polystyrene.The product was characterized by several methods,The UVspectra show that the living anionic polystyrene species can react with C60.The GPCresults proved that the mount of C60 do not influence the degree of the substi tution, All C60 is bissubstituted.The DSCresults illustrate that only one glass transition temperature was observed in each case.As the weight percent of C60 increased in the polymer,the Tg increased from 94.4℃ (PS) to 96.9℃ (PSC1) and 97.6℃ (PSC2).The obtained polymeric C60 derivative is brown and brittle glass,and the intensity of brown color depends on the amount of C60 in combination, Polymeric C60 derivatives can be dissolved in a variety of solvents,such as THF, toluene, trichloromethane,and so on.Its solubility behavior is similar to polystyrene itself and totally unlike C60.
    Effect of Ethylene Prepolymerization in C2H4/H2 Atmosphere with Ti-Mg Catalyst on Gas-phase Ethylene Polymerization
    LI Yue, LIN Shang-An
    1996, 17(7):  1154-1156. 
    Asbtract ( )   PDF (222KB) ( )  
    Related Articles | Metrics
    Ti-Mg catalyst treated by novel prepolymerization in C2H4/H2 atmosphere shows a high activity and non-decaying kinetic profiles in gas-phase ethylene polymerization.The prepolymerization drastically reduces the initial polymerization rate and increases the bulk density (BD) of the resulting polymer product, exhibiting a similarity to the prepolymerization in C2H4/N2 atmosphere, Characterization of the resulting polymer particle by SEMdemonstrates bound agglomerates of fine secondary polymer globules for the polymer surface,which could be effective for increasing BDof the product.
    Pteparations and Adsorption Properties of Amino Modifiedβ-Cyclodextrin Cross-Linked Polymers
    CHEN Yong-Ming, HE Bing-Lin
    1996, 17(7):  1157-1159. 
    Asbtract ( )   PDF (342KB) ( )  
    Related Articles | Metrics
    Cyclodextrin epichlorohydrin cross-linked polymers modified with diethylamine,ethylene diamine and diethylene triamine were prepared under controlled conditions.Adsorption abilities of the modified polymers for o,p-nitrophenol were enhanced while selectivity for the structural isomers had not been found in the literatures, Adsorption behavior conformed to Freundlich isotherm equation and equilibrium constants were evaluated.Enhanced adsorption abilities were explained as a result of the additional acid base interaction besides inclusion.
    Application of Macromolecular Stabilizer for Pearl Bleaching
    ZHANG Bing-Jian, ZHANG Xiao-Li
    1996, 17(7):  1160-1161. 
    Asbtract ( )   PDF (168KB) ( )  
    Related Articles | Metrics
    Anew macromolecular stabilizer PMHfor pearl bleaching is selected and studied.1～1.5 mL/LPMHcan inhibit effectively decomposition of H2O2 and the bleaching rate can thus be increased by 20%,The quality of pearl surface is also improved after bleaching.
    The Reactivity Ratios of Group Transfer Copolymerization of Acrylonitrile with Methacrylates
    ZOU You-Si, GUO Jin-Quan, LAN Tao, DAI Li-Zong, PAN Rong-Hua
    1996, 17(7):  1162-1163. 
    Asbtract ( )   PDF (269KB) ( )  
    Related Articles | Metrics
    Random copolymerization have been performed for three binary systems using 1-methoxy-2-methyl-1-trimethylsilyloxy propene(initiator) and tetrabutvlammonium bibenzoate(catalyst) in tetrahydrofutran solution.The copolymer compositions were determined by elementary analysis for nitrogen and the results evaluated by the Kelen-Tudos method.The monomer pairs concerned are (1)acrylonitrile(AN) and methyl methacrylate(MMA),(2)AN and ethyl methacrylate(EMA),(3)AN and butyl methacrylate (BMA).The reactivity ratios determined in this study are:(1)rAN=10.22, rMMA=0.07;(2)rAN=5068,rEMA=0.16;(3)rAN=8.59,RBMA=0.09.
Special Issues
More...
Download
More...
Links
More...