Loading...
CJCU

Table of Content

    24 July 1998, Volume 19 Issue 7
    Previous Issue    Next Issue
    Articles
    Synthesis of Fullerene Ethylenediamine Derivative Platinum Complex and Its Catalytic Behavior in the Hydrosilylation of Olefins
    CHEN Yuan-Yin, FANG Peng-Fei, ZHU Ling, SHENG Rong-Sheng
    1998, 19(7):  1011-1015. 
    Asbtract ( )   PDF (509KB) ( )  
    Related Articles | Metrics
    Fullerene derivative ethylenediamine platinum complex was prepared by reacting fullerene(C60) with ethylenediamine, potassium chloroplatinite sequentially. The complex exhibited high catalytic activities for the hydrosilylation of olefins with triethoxysilane, and nearly 100% regioselectivity for styrene α-adduct.
    The Coordination of Rare Earth Elements with Derivatives of Catechol(Ⅴ) The Coordination and Transformation Reaction of Cerium with 3,4-Dihydroxybenzoic Acid
    DENG Jian-Cheng, ZHU Mei-Xiang, ZHONG Chao-Fan, TONG Jue
    1998, 19(7):  1016-1019. 
    Asbtract ( )   PDF (455KB) ( )  
    Related Articles | Metrics
    The complex of cerium(Ⅲ) with 3,4-dihydroxybenzoic acid was prepared in aqueous solution of pH=5.6～9.0, and the formula Ce(H2L)2(OH)·3H2O was determined by means of IR, TG-DTA and elementary analysis. In alkaline aqueous solution, the cerium cation of the complex can be transformed from carboxyl group to dihydroxyl group in the same ligand and formed a new chalation compound.
    A Novel Spin Transition Compound with Hysteresis [Fe(PhCH=Ntrz)3](BF4)2·3H2O
    WANG Hong-Mei, LI Li-Cun, YANG Guang-Ming, LIAO Dai-Zheng, YAN Shi-Ping, JIANG Zong-Hui, WANG Geng-Lin, WU Wei-Fang, WANG Yun-Bo
    1998, 19(7):  1020-1022. 
    Asbtract ( )   PDF (444KB) ( )  
    Related Articles | Metrics
    Spin transition complexes are of great interest because of their potential application in molecular based electronic devices such as optical memory and switches. Anovel linear polynuclear spin transition complex[Fe(PhCH=Ntrz)3](BF4)2·3H2O(where PhCHNtrz stood for the Schiff base condensed by 4-NH2-1,2,4-triazole and benzaldehyde) was synthesized and characterized by elemental analysis, molar conductance, IR and UV-V is spectra, magnetic measurements and temperature-dependence optical detection. The spin transition occurred at 105～235 K with hysteresis and pronounced thermochromism. TC↑=180 K, TC↓=169 K, hysteresis width 11 K.
    Studies on the Hydrothermal Synthesis and Spectral Properties of BaBeF4:Sm3+
    ZHAO Chun-YAN, ZHU Lian-Jie, FENG Shou-Hua, CAO Zhi-Cheng, XU Ru-Ren
    1998, 19(7):  1023-1025. 
    Asbtract ( )   PDF (161KB) ( )  
    Related Articles | Metrics
    In this paper, we presented the hydrothermal synthesis of BaBeF4:Sm3+at a low temperature and studied the excitation and emission spectra of BaBeF4:Sm3+and emission intensities of Sm3+in BaBeF 4 as a function of Sm3+concentration.
    Spectroelectrochemical Characteristics of Tetra-(α-naphythyl) Tetrabenzoporphyrin Cobalt Complex
    SHI Tong-Shun, ZHANG Xu-Guang, LIU Wei, JIA Bai-Wen, LIU Guo-Fa
    1998, 19(7):  1026-1028. 
    Asbtract ( )   PDF (445KB) ( )  
    Related Articles | Metrics
    The electrochemical and spectroelectrochemical behaviour of tetra (α-naphythyl) tetrabenzoporphyrin cobalt complex, TNTBPCo, was studied by cyclic voltammetry, in situ FTIR and in situ UV-V is spectroelectrochemistry. The different oxidation states of the complex were obtained by controlling potential electrolysis at different potentials, and this electronic spectra and molecular vibration spectra were studied. The first and second redox processes of TNTBPCo(Ⅱ) correspond to the centre metal cobalt(Ⅱ) to form TNTBPCo(Ⅲ)+or TNTBPCo(Ⅰ)-. The third reduction step is the addition of one electron to the porphyrin ring. The Soret band of TNTBPCo moves to low wavelength as the oxidation state of the complex decreases. The oxidation state sensitive bands of TNTBPCo were found to be in the 1660, 1476, 1142, 924 and 998 cm-1and these bands shift to low frequency as the oxidation state of the centre metal decreases.
    Synthesis and Anti-virus Activity of Heteropoly Tungstosilicate Substituted by Niobium
    LIU Jie, WANG En-Bo, PENG Jun, HU Chang-Wen, YAN Shu-Zhen
    1998, 19(7):  1029-1031. 
    Asbtract ( )   PDF (1214KB) ( )  
    Related Articles | Metrics
    Five kinds of heteropoly compounds substituted by niobium have been synthesized and characterized by elementary analysis, IR, UVand 183WNMR. The activities of anti green pepper cucumber mosaic virus for these heteropoly compounds have been examined for the first time. It was found that two of them have excellent anti virus activities. The relationships between the structure of the compounds, anti ion and water dissolvability and antivirus activities have been studied.
    Surface Reduction Study of Monoazo Dyes by Adsorptive Square Wave Voltammetry
    XU Gang, O Dea J. J., Osteryoung J. G.
    1998, 19(7):  1032-1039. 
    Asbtract ( )   PDF (829KB) ( )  
    Related Articles | Metrics
    The surface reduction behavior of nine monoazo dyes at the static mercury drop electrode has been studied by means of adsorptive square wave voltammetry. Three types of surface reduction behavior are seen among the nine azo dyes. Two of them are modeled as a two-step mechanism in which the first step is a quasireversible reduction followed by a totally irreversible reduction. For those dyes having strong electron-repelling groups such as amino or dimethylamino, the second reduction occurs at a potential almost the same as that of the first, and only one peak is observed. The second step gradually separates from the first step as the pHvalue of the solution increases. For those azo dyes having methoxy or hydroxy substituents, two peaks are observed; one is quasireversible, the other is totally irreversible. The second irreversible step gradually overlaps the first step as the pHvalue of the solution decreases. The third type voltammogram of these monoazo dyes displays a single irreversible peak that is modeled as a four-electron one-step irreversible reduction. The surface reduction behavior is quantitatively explained by the proposed models. The kinetic parameters for these surface reactions are obtained by non-linear least squares(COOL) analysis of the voltammograms. These techniques are useful for both establishing mechanism and chemical analysis.
    Resonance Rayleigh Scattering Method for the Determination of Trace Amounts of Molybdenum with Thiocyanate-basic Triphenylmethane Dye Systems
    LIU Shao-Pu, ZHOU Guang-Ming, LIU Zhong-Fang, LI Ming
    1998, 19(7):  1040-1044. 
    Asbtract ( )   PDF (1444KB) ( )  
    Related Articles | Metrics
    Studies on the resonance Rayleigh scattering (RRS) spectra of the ion association complexes of [MoO(SCN)5]2-were carried out with the basic triphenylmethane dye such as crystal violet (CV), ethyl violet (EV), malachite green (MG), brilliant green (BG) and iodine green (IG). The spectral characteristics, the effect factors and the optimum reaction conditions have been investigated. The quantitative relationships of the intensities of RRSto the concentration of molybdenum were established. The new and highly sensitive ways for the determination of molybdenum by RRShave been proposed. The methods can be applied to the determination of trace amounts of molybdenum in steel with satisfactory results.
    Investigating Anisotropic Micro-crystal Using Polarization Contrast in Scanning Near-field Optical Microscope
    TANG Ming, CAI Sheng-Min, LIU Zhong-Fan, OUYANG Min, XUE Zeng-Quan
    1998, 19(7):  1045-1048. 
    Asbtract ( )   PDF (210KB) ( )  
    Related Articles | Metrics
    A scanning near-field optical microscope(SNOM) was used to observe rodamine 6G micro-crystal by using polarization contrast. SNOMimage with a round polarized incident light correlated well with the shear-force topography image of crystals. However, with linearly polarized light, anisotropic absorption was found. When the polarization direction was parallel to strongly absorbing direction, the optical contrast came mainly from the sample absorption, therefore, well resolution was obtained in its perpendicular direction. However, when the polarization direction was perpendicular to the strongly absorbing direction, optical contrast came mainly from the complex interaction between the near-field light and the sample, which improved the resolution in the perpendicular direction. When the direction was 45° to the absorbing direction, optical contrast came from both of the near-field interaction mechanism and the absorbing mechanism, and a good resolution image was obtained. The present work demonstrates that the polarization contrast has a great application to the studies of anisotropic materials.
    A Strategy of Dimension Compressing in Pattern Classifications and Its Applications to Processing Complex Chemical Information
    CHEN De-Zhao, CHEN Ya-Qiu, GAO Yuan, LIN Ji-Xiong, HU Shang-Xu
    1998, 19(7):  1049-1053. 
    Asbtract ( )   PDF (218KB) ( )  
    Related Articles | Metrics
    A new correlative component analysis method was adopted to deal with the pattern classification problems of the complex chemical information. The classification correlation components obtained from the patterns of high dimensionality are not only mutually independent, but also concentrate pattern classification information from the original patterns. In order to select a reasonable number of components, an algorithm was proposed in this study, named ratio of correlative index method, in which the necessary number of components is fixed as the correlative components are calculated. Therefore, the original pattern was transformed to a compressed new pattern of lower dimensionality, and the characteristics of the new pattern was improved, thus the classification effectiveness was improved either. Finally, multi-classes example of spearmint essence was applied to check the validity of this new method. The results showed that, the calculation of this new method is really convenient and it is an applied method for multi classes classification problem of complex chemical information backgrounds.
    Classification Study by Pattern Recognition on the Relationship Between the Trace Elements in Human Hair and Sex
    ZHANG Yuan, ZHU Er-Yi, ZHUANG Zhi-Xia, LI Bo, WANG Xiao-Ru
    1998, 19(7):  1054-1056. 
    Asbtract ( )   PDF (367KB) ( )  
    Related Articles | Metrics
    The data of 22 trace elements concentrations in human hair samples were obtained by ICP-AES and GFAAS. The variables which have significant influence on discriminating the sex are selected through the treatment of the concentration data by the variable dimension expansion and the variable selection methods. The discrimination plane figure with the good classification is obtained through the treatment of the data with selected variables by PLSmethod. The prediction models are built and used to distinguish the human sex according to the element concentrations data in human hair. The accuracy of the prediction is 81%.
    Spectroscopic Studies on the Binding of Lanthanides to Apoovotransferrin
    YANG Bin-Sheng, Wesley R. Harris
    1998, 19(7):  1057-1061. 
    Asbtract ( )   PDF (359KB) ( )  
    Related Articles | Metrics
    The binding of Eu3+to chicken egg apoovotransferrin has been studied by monitoring the change of differential UVspectra at 245 nm. Conditional equilibrium constants for the complexation of Eu3+with chicken egg apoovotransferrin in 0.1 mol/Lhepes, pH7.4, at 25 ℃ have been measured. The results are lgK1=8.21±0.20 and lgK2=4.60±0.11 for complexation of Eu3+. The molar absorptivity per binding site for Eu3+is (2.1±0.1)×104cm-1·L·mol-1. The titration of N-terminal monoferric ovotransferrin with Eu3+(differential UVspectra) and Tb3+(fluorescence) indicate that the binding of lanthanide ions at N-terminal binding site is stronger than that at C-terminal binding site.
    Separation and Preconcentration of Trace Gold, Platinum, Palladium in Geological Samples with Alizarin Red-S Chelate Resin and Its Determination
    LI Zeng-Wen, BAO Chang-Li, ZHANG Kai
    1998, 19(7):  1062-1064. 
    Asbtract ( )   PDF (178KB) ( )  
    Related Articles | Metrics
    The conditions for synthesis of alizarin red-Schelate resin and for separation and preconcentration of Au, Pt and Pd in geological samples have been investigated in this paper. Experiments show that Au, Pt and Pd in solution are enriched on alizarin red Schelate resin column in pH 1.0 HCl and are eluted with 3% acidic thiourea. The recoveries of Au, Pt and Pd are 94.5%～104.1%. The results obtained by the analysis of a standard sample are satisfactory. It is proved that alizarin red-S chelate resin bear sulfonic group with-SO3H as ion exchanging group can be used for separation and preconcentration of Au, Pt and Pd in geological samples and can be used repeatedly more than 3 times.
    Studies on Syntheses and Spectral Character of Bis[N,N'-alkylene-2,2-(arylmethylene)bis(3,4-dimethyl pyrrole-5-aldimino)] Dimanganese(Ⅱ) and Their Biomimetic Catalytic Character for the Monooxygenation of Cyclohexane with PhIO
    CHEN Xin-Bin, GUI Ming-De, ZHU Shen-Jie, GUO Can-Cheng
    1998, 19(7):  1065-1069. 
    Asbtract ( )   PDF (242KB) ( )  
    Related Articles | Metrics
    This paper first reports the syntheses and spectral character of bis[N,N'-alkylene-2,2-(phenylmethylene)bis(3,4-dimethylpyrrole-5-aldimine)](alkylenes: 1,3-propylene; 1,4-butylene; 1,2-phenylene; 4-methyl-1,2-phenylene), bis[N,N'-(1,2-ethylene)2,2-(4-methoxyphenylmethylene)bis(3,4-dimethylpyrrole-5-aldimine)] and their dimanganese(Ⅱ) complexes as well as the biomimetic catalytic properties of the complexes for the monooxygenation of cyclohexane with PhIO.
    Synthesis and Crystal Structure of 1,3,3a,5-Tetraphenyl-3a,4,5,11-tetrahydro-3H,6H-1,2,4-triazolobenzodiazepine
    XU Jia-Xi, JIN Sheng, ZHANG Ze-Ying, MAK Thomas C. W.
    1998, 19(7):  1070-1073. 
    Asbtract ( )   PDF (1697KB) ( )  
    Related Articles | Metrics
    The title compound was synthesized by [2+3] cycloaddition reaction of 2,4-diphenyl-2,3-dihydro-1H-1,5-benzodiazepine and benzenecarbohydrazonic chloride and its crystal structure was determined by Xray diffraction method. The single crystals belong to orthorhombic, space group Fdd2 with a=1.7628(4) nm, b=5.7512(12) nm, c=1.0227(2) nm, V=10.368(5) nm3, Z=16, DC= 1.262 g·cm-3, μ=0.075 mm-1, F(000)=4160 for 1339 reflections, R=0.0461, RW= 0.0560.
    Synthesis and Characterization of 1-Acyloxy(acylamino)-2,8,9-trioxa-5-aza-1-stannatricyclo[3,3,3,01.5] Undecanes
    LI Jing, TANG Yong-Jun, LIU Hua, DONG Shu-Ping, XIE Qing-Lan
    1998, 19(7):  1074-1077. 
    Asbtract ( )   PDF (298KB) ( )  
    Related Articles | Metrics
    Fourteen new 1-acyloxy(acylamino)stannatrane were synthesized. The IR, 1H, 13C, 119SnNMR and elemental analysis were determined. The characteristics of NMRspectra in different solvents showed that the dimer present in chloroform(CDCl3) is decomposed into a monomeric species, involving the very nucleophilic dimethylsulfoxide(DMSO) as a ligand.
    Synthesis of C(10)-(4-sulfonato phenyl)biliverdin Analog
    YAO Tuan-Li, JIN Sheng, WANG Chang-Qi, MA Jin-Shi
    1998, 19(7):  1078-1081. 
    Asbtract ( )   PDF (188KB) ( )  
    Related Articles | Metrics
    A new bile pigment of 1,19,22,24-tetrahydro-2,3,7,8,12,13,17,18-octamethyl-10-(4-sulfonato phenyl)-1,19-dioxo-21H-biline was synthesized and confirmed by IR, 1HNMR, 13CNMR, and MS. Its complex with Zn2+was studied using absorption spectra which indicated that the complex contains two zinc ions and one biliverdin.
    Synthesis of Some New Chromones and Pyrimidinones Containing 2-Phenyl-1,2,3-triazole
    LIU Fang-Ming, YU Jian-Xin, WANG Mei, LIU Yu-Ting, CHEN Yao-Zu
    1998, 19(7):  1082-1085. 
    Asbtract ( )   PDF (1639KB) ( )  
    Related Articles | Metrics
    The preparation of five new 2-heterocyclic substituted chromones and of ten new related pyrimidinones is reported. Condensation of 2-hydroxy acetophenones Ⅰa-Ⅰewith 2-phenyl-1,2,3-triazole-4-carboxylic acid followed by Baker Venkataraman rearrangement led to 1,3-diketones Ⅲa-Ⅲe, which yielded chromones Ⅳa-Ⅳeon dehydration and pyrimidinones Ⅴa-Ⅴeon condensation with urea and thiourea respectively. Their structures were confirmed on the basis of elemental analysis, IR, 1HNMR and MSs pectral data.
    Synthesis of the Precursor Compound of Sinulariol-D, Sinularial-A and Sinularic Acid-A
    CEN Wen, XING Ya-Cheng, LI Yu-Lin
    1998, 19(7):  1086-1089. 
    Asbtract ( )   PDF (214KB) ( )  
    Related Articles | Metrics
    A precursor(15) of Sinulariol-D, Sinularial-A and Sinularic Acid-A, (E,E,E)-2,6,10,14-tetramethyl-2,3-epoxy-16-phenylsulfide-6,10,14-sixdecatriene-1-ol, was prepared from geraniol through 9 steps.
    Matrixassisted Laser Desorption/Ionization Mass Spectral Study of Saccharides
    HAO Chun-Yan, MA Xiu-Li, LIU Zhi-Qiang, JI Yi-Ping, LIU Shu-Ying, LIU Chang-Cheng, SUN Yun-Xiu, LIU Ju-Zheng
    1998, 19(7):  1090-1094. 
    Asbtract ( )   PDF (550KB) ( )  
    Related Articles | Metrics
    Matrixassisted laser desorption/ionization (MALDI) mass spectra of saccharides with three common matrixes were studied here. It is shown that Na+and K+play important roles in the determination of oligasaccharide molecule weight and the molecular weights(MW) of glucans(dextran) with MW more than 10 000 is determined successfully with the help of column chromatography. By comparing the effects of three matrixes in saccharide analysis and comparing positive ion and negative ion matrixassisted laser desorption/ionization mass spectra of oligo- and polysaccharides, the most suitable matrix for saccharide analysis, 2,5-dihydroxylbezonic acid (DHB), is selected and the ion formation processes of saccharides under matrix-assisted laser adsorption/ionization condition are clarified.
    Synthesis and Carbon Unit Transfer Reactions of Methyl Substituted N5, N10-Methenyl-tetrahydrofolate Coenzymes
    ZHAO Bing-Jun, XIA Chi-Zhong , CHENG Jin-Pei
    1998, 19(7):  1095-1100. 
    Asbtract ( )   PDF (488KB) ( )  
    Related Articles | Metrics
    Acetamide reacts with 1,2-diaminoethane to yield diacyl ethylenediamine, and the consecutive reaction with magnesium and m(or p)-nitrophenylsulfonyl chloride and methyl iodide gives 1,2-dimethyl-3-m (or p)-nitrophenylsulfonyl imidazolinium salts that serve as the models of N5,N10- C+R-tetrahydrofolate(THF) coenzymes(2a, 2b). The latter salts with monofunctional nitrogen nucleophiles(p-methyl aniline, p-methoxy aniline and so on) and carbon nucleophiles(malononitrile) give the intermediate of ethylidyne transfer reaction. Bifunctional nucleophiles (1,2-diaminobenzene, 2-aminophenol) react with 2a and 2b to yield ethylidyne transfer products.
    Studies on Inclusion Compound of Quercetin with β-Cyclodextrin
    SHAO Wei, WANG Jin-Shan, WANG Chun-Xiang, MI Guang-Tai, WANG Da-Qing
    1998, 19(7):  1101-1103. 
    Asbtract ( )   PDF (364KB) ( )  
    Related Articles | Metrics
    The aim of this study was to improve the solubility of quercetin in aqueous solution. The inclusion compound of quercetin with β-cyclodextrin was obtained by saturated aqueous solution method. The formation of the inclusion compound was confirmed by IR spectroscopy and differential scanning calorimetry. The content of quercetin inclusion was determined by UV. The results indicated that the inclusion compound of quercetin with β- cyclodextrin was formed. The dissolubility of quercetin in inclusion form increased from 2.78 μg/mL to 23.15 μg/mL. The experimental data of inclusion compound fitted well to the molar ratio of 1:1. Through the thermodynamic study we got the constants and ΔrHm0, ΔrSm0, ΔrGm0 of the inclusion at different temperatures.
    Studies on Immobilization of Urease on Cellulose Acetate Membrane
    WANG Jie, SONG Xi-Jin, WU Ming, REN Zhong-Jiao, YUAN Bin, LEI Zhuo-Lin
    1998, 19(7):  1104-1106. 
    Asbtract ( )   PDF (465KB) ( )  
    Related Articles | Metrics
    Urease was immobilized on cellulose acetate membrane by entrapment. The activity yield and stability of urease immobilized membrane were investigated in catalyzing hydrolysis of urea. The experimental results showed that the activity of urease membrane was related to water content of casting membrane solution. After the enzymatic membrane was used repeatedly for 10 times, the residual activity of urease on the membrane retained 60% of its original. After storage at 4 ℃ for 3 months almost no decrease of enzymatic activity was observed. The optimal pHand temperature of the hydrolysis reaction were also studied. The results showed that this urease immobilized membrane can be used under a wide operational condition.
    Synthesis and Sulfonation of Layered Zirconium Phosphate Phenylphosphonate
    XIAO Jin-Bing, XU Jin-Suo, TANG Yi, GAO Zi
    1998, 19(7):  1107-1111. 
    Asbtract ( )   PDF (225KB) ( )  
    Related Articles | Metrics
    The main factors in the synthesis of layered zirconium phosphate phenylphosphonate Zr(PO4H)2-n(PO3Ph)nwere investigated. At F-/Zr4+=12 and H3PO4/Zr4+=20, a series of homogeneous Zr(PO4H)2-n(PO3Ph)n(n=0～2) were synthesized by changing the amount of phenylphosphonic acid. The crystals are thermally stable below 400 ℃. The phenyl groups in the layered structure can be sulfonated almost quantitatively. The sulfonated products Zr(PO4H)2-n(PO3PhSO3H)nhave abundant acidic sites and they are also stable below 300 ℃.
    FTIR and TPD Studies of Adsorption Properties of Nitrogen Monooxide over Copper Ion exchanged Zeolites
    ZHANG Wen-Xiang, JIA Ming-Jun, ZHANG Chun-Lei, ZHANG Li-Hua, WU Tong-Hao, SUN Tie, YAHIRO Hidenori, IWAMOTOM asakazu
    1998, 19(7):  1112-1116. 
    Asbtract ( )   PDF (365KB) ( )  
    Related Articles | Metrics
    The relations of the adsorption properties and the behavior of catalytic decomposition of nitrogen monooxide over various copper ion-exchanged zeolites were studied by the means of in situ FTIR and temperature-programmed desorption (TPD). The results demonstrated that NO+, O--Cu-NO and NO3- species were formed on the surface of the zeolites and desorbed at 350～400 K(denoted as α), 400～480 K(β) and 650～700 K(γ), respectively. It was found that the kinds and the amounts of the species were greatly changed with the zeolite structure and the copper ion exchange level, i. e . Cu-MFI, Cu-MOR and Cu-OFF/ERIgave α, β and γ peaks; Cu-FER gave α and β peaks; Cu -LTLand Cu-FAU only gave α peak. The amounts of desorption were increased linearly with the exchange level of copper on Cu-MFI. The O2desorption peak appeared at the same temperature as that of the γ peak. In addition, by comparing the present results with the behavior of catalytic decomposition of NO, it is also found that NO3- species play a key role in the catalytic decomposition of NOand the formation of O2over the zeolites.
    Studies on the Aggregation and Interaction of DDAPS Micelles with Fluorescence and Light-Scattering Methods
    LI Fang, LI Gan-Zuo, WANG Han-Qing, An Ying-Li
    1998, 19(7):  1117-1120. 
    Asbtract ( )   PDF (267KB) ( )  
    Related Articles | Metrics
    Steady fluorescence and dynamic light-scattering measurement were reported for dodecyldimethylammoniopropanesulfonate(DDAPS)/NaCl aqueous micellar system. The results show that the aggregation number and the hydrodynamic radius of DDAPSmicelles increase slightly with the increasing of NaCl concentration and decrease slightly as the temperature rises. For the zwitterionic surfactant system we infer repulsive intermicellar interactions in spite of the absence of net charges. DDAPSbehaves somewhat like an ionic surfactant. Within the scope of our investigation, DDAPSmicelles exist in spherical shape.
    Effect of Nonideality on Chemical Oscillatory Dynamical Regime of Belousov-Zhabotinskii Reaction System
    HUA Da-Yin, LUO Jiu-Li
    1998, 19(7):  1121-1125. 
    Asbtract ( )   PDF (222KB) ( )  
    Related Articles | Metrics
    Based on the Debye-Hükel activity coefficient theory of electrolyte solution, the activated complex theory of reaction rate and the singular theory of three variables differential equation, a series of theoretic investigation of BZreaction reported in this paper is devoted to explore the influence of the nonideality on chemical oscillatory dynamical regime. Using the Oregonator Model, a systematic dynamics of the nonideal homogeneous BZ reaction system is proposed. The threshold of chemical oscillation is calculated and then the critical diagram "concentration of NaBrO3-ionic strength" has been drawn. By means of it the regime of oscillation could be fixed quantitatively. Aset of experiments has also been done. The results is in accordance with the theoretical conclusions.
    An Ab Initio Investigation of the Molecular Orbital and Stabilization Energy for Substituted Lithium Carbene Cations
    LI Ji-Hai, FENG Sheng-Yu
    1998, 19(7):  1126-1130. 
    Asbtract ( )   PDF (222KB) ( )  
    Related Articles | Metrics
    Metal carbene cations, found in recent ten years, is a class of unstable intermediates with a high activity. In this paper, with CH2Li+as a model compound, we first investigted the relative stabilization energies and molecular orbitals of substituted lithium carbene cations by ab initio method. The studies show that the substituents with π donation have the biggest stabilization because they can form a two electron-multicentre conjugated orbital with carbene carbon and lithium in their planar configurations. In contrast, their stabilization energies are less in perpendicular one. The π donation plays a leading role in the substituents with both π donation and σ induction. Then the substituents with only σ inductive effets have destabilization. The most of LUMO of lithium carbene cations are conjugated molecular orbitals formed by empty pzof carbene carbon, lithium and substltuents, and the carbene carbon is the major consistent. Their energy levels all are negative values, so they can be considered with a high electrophilic activity and the acting centre should be on the carbene carbon.
    Theoretical Research on the Structures and Electronic Spectra of Free Radical C69N and Its Dimer (C69N)2
    REN Ai-Min, FENG Ji-Kang, TIAN Wei-Quan, SUN Xiu-Yun, GE Mao-Fa, HUANG Xu-Ri, SUN Jia-Zhong
    1998, 19(7):  1131-1135. 
    Asbtract ( )   PDF (240KB) ( )  
    Related Articles | Metrics
    Computation on radical C69N and dimer (C69N)2by INDO series methods suggests that the introduction of Ninto the cage framework distorted the cage with the Nstretching out of the cage, the carbon atom in the 6-6 bond which bonds with Natom has large spin densities, where two radicals were bound through C-C single bond to form dimer (C69N)2with C2h symmetry. The Natom bonds with the three connected carbon atoms by single bond. The calculated electronic spectra are consistent well with that of the experiment. The dimer (C69N)2readily dissociates to the monomer.
    Studies on the Stress in Cubic Boron Nitride Films by Infrared Spectroscopy
    ZHAO Yong-Nian, ZOU Guang-Tian, WANG Bo, HE Zhi, ZHU Pin-Wen, TAO Yan-Chun
    1998, 19(7):  1136-1139. 
    Asbtract ( )   PDF (445KB) ( )  
    Related Articles | Metrics
    A RF sputtering was used for preparing cubic boron nitride (c-BN) films. The results from infrared spectra and transmission electron diffraction show that a pure c-BN film with a high crystallinity was obtained. The analyzing of IRspectra indicate that the negative substrate bias is an important condition, and also the reason to form the stress, the higher the bias, the higher the stress. Comparing the reflecting IRabsorption spectra with the transmission IRabsorption spectra, it is first found that the stress on the surface layer of c-BN film is smaller than that in c-BN film. In terms of its compressive stress mode of the growth of c-BN should be limited by a very small stress on the surface layer of c-BN film. A-BN film with the layer-built was specially prepared for investigating the distribution of the stress on the surface layer of c BNfilm. The cracks resulted from the stress of c-BN film were first kept miraculousness. The arrangement of the cracks shows the distribution of the stress on the surface layer of c-BN film at the horizontal direction.
    Diamond Growth Condition at Low-Pressure Influenced by Addition of Oxygen
    LIU Zhi-Jie, WAN Yong-Zhong, ZHANG Wei, ZHANG Jian-Yun, WANG Ji-Tao
    1998, 19(7):  1140-1143. 
    Asbtract ( )   PDF (190KB) ( )  
    Related Articles | Metrics
    Diamond growth using CO-H2and CO-O2-H2as input gases was studied based on the non-equilibrium thermodynamic coupling model. The phase diagrams of diamond growth with different content of oxygen in the reaction system were calculated. The diagrams have diamond growth regions, which were different from the diagrams based on classical equilibrium thermodynamics. Also, the diamond growth regions at different system pressures and different contents of oxygen were discussed in this paper. These results can guide the experimental study on diamond growth at low-pressure because the theoretical phase diagrams coordinate very well with the experimental results which had been published.
    Crystal Structure and Quantum Chemical Study of the 3-Benzyloxycarbonyl-1,3-thiazolidine-2-thione
    LI Ye-Zhi, GUO Chun-Xiao, HU Xue-Shan, DU Li-Ping, HUANG Hua-Min
    1998, 19(7):  1144-1147. 
    Asbtract ( )   PDF (272KB) ( )  
    Related Articles | Metrics
    The title compound was synthesized by reaction of benzyloxycarbonyl chloride and 1,3-thiazolidine-2-thione in the presence of Et3N. The crystal structure was determined by Xray diffraction technique. The crystal is triclinic, space group P1 with a=0.6274(2) nm, b=0.7340(3) nm, c=1.2976(4) nm; α=100.73(3)°, β=94.53(3)°, γ=103.28(3)°, V=0.5667(3) nm3, Z=2. The >C=O and >C=O groups in the molecule are located in the same sides of C(4)-N-C(1) bonds with cis configuration. The electronic structure, the distribution of calculated net charges and bond orders, and the nature of the near frontier orbital were studied by PM3 molecular orbital method.
    The Investigation of the Various Structures of DNA Molecules(Ⅰ) The Coil Globe Transition of λ-DNA Induced by the Cation Surfactant
    FENG Xi-Zeng, LIN Zhang, WANG Chen, BAI Chun-Li
    1998, 19(7):  1148-1150. 
    Asbtract ( )   PDF (314KB) ( )  
    Related Articles | Metrics
    The interaction between cetyltrimethylammonium bromide(CTAB) and λ-DNA was studied by SEM and AFM. It is clear that λ-DNA molecules exhibit discrete conformational change between the coil and globule states with the addition of cationic surfactant. When the concentration of CTAB is less than 2×10-6mol/L, all DNAmolecules exhibit the extended coil state. Whereas, when the CTAB concentration is higher than 8.0×10-6mol/L, only compacted DNA molecules in the globular state are observed. To study of coil globule transition, the process of the structural change from the coilinto the globule state is observed under the spatial gradient of the CTABconcentration. The formation of aggregates from two or more globules is noticed at high concentrations of surfactant above 8.0×10-5mol/L. The surfactant λ-DNA complex has a hydrophobic region akin to ordinary micelle.
    Gas Phase Ion-molecule Reactions of C60with Methyl Ethers CH3OCnH2n+1
    MA Li, LIU Zi-Yang, WANG Wei-Jie, GUO Xing-Hua, LIU Shu-Ying
    1998, 19(7):  1151-1153. 
    Asbtract ( )   PDF (174KB) ( )  
    Related Articles | Metrics
    Gas phase ion molecule reactions of buckminsterfullerene (C60) with the ion systems generated from the self chemical ionization of alkyl methyl ethers(CH3OCnH2n+1, n=2, 3, 4) were studied in the ion source of a mass spectrometer. The adduct cation [C60C2H5O]+and protonated molecular ion [C60H]+ were observed as the major products. The former was produced by the reactions of C60with the methoxymethyl ion [CH3O=CH2]+, the latter corresponded to the proton transfer reactions from the protonated alkyl methyl ethers to C60. It is suggested that the [3+2] cycloadduct is the most favorable structure among the probable isomers with special chemical properties. Our investigation provides the guidance for the synthesis of this compound in condensed phase.
    Catalytic Oxidation of α-Eicosanol to α-Eicosanoic Acid over MCM-48 Molecular Sieves Containing Transition Metal
    WEI Chang-Ping, CAI Qiang, WANG Hai-Jun, BI Ying-Li, PANG Wen-Qin, ZHEN Kai-Ji
    1998, 19(7):  1154-1156. 
    Asbtract ( )   PDF (754KB) ( )  
    Related Articles | Metrics
    A series of MCM48 mesoporous molecular sieves containing copper, zirconium, chromium, cobalt, manganese, molybdenum and iron were prepared by hydrothermal crystallization and characterized by IR, Py IR and XRD. The series of molecular sieves were used to perform the catalytic oxidation of α-long chain eicosanol to the corresponding α-eicosanoic acid. The results monitored by IRtechnique were consistent with those of chemical analysis.
    Preparation and Characterization of Phenoxy Resin/ Poly(4-vinylpyridine) Interpolymer Complexes
    XU Sheng-Qing, ZHAO Han-Ying, CHEN Bin, HUANG Bao-Tong
    1998, 19(7):  1157-1161. 
    Asbtract ( )   PDF (1500KB) ( )  
    Related Articles | Metrics
    The compositions and structures of interpolymer complexes formed by mixing phenoxy resin (PHEB) and poly(4-vinylpyridine) (P4VPy) in chloroform have been studied by means of elemental analysis, DSC, FTIR, UVand XPS. In the meantime, the corresponding blends prepared have been characterized and compared. The results show that compositions of the complexes were identical with the ratio of equimolar interactive units. All blends were miscible and their compositions were related to the feed ratios. Based on the experimental results, process of formation of the complex is depicted.
    Synthesis of Graft Copolymer by Coupling Reaction of Living Polymethyl Methacrylate with Bromomethylated Polystyrene
    ZOU You-Si, GUO Jin-Quan, DAI Li-Zong, ZHANG Jing-Hui, PAN Rong-Hua
    1998, 19(7):  1162-1165. 
    Asbtract ( )   PDF (177KB) ( )  
    Related Articles | Metrics
    A novel well defined graft copolymer(PS-g-PMMA) with control over the length of both backbone and side chain was synthesized by coupling reaction of living polymethyl methacrylate with bromomethylated polystyrene. The backbond polymer was prepared by anionic polymerization of styrene with n-butyllithium followed by bromomethylation using C8H17OCH2Br/SnCl4. The living PMMA was prepared by group transfer polymerization of MMA. The graft copolymers with narrow molecular weight distribution, D=1.2～1.4, at the Mn of around 3×104～7×104were obtained. The reactivity of the BMPS and living PMMA decrease with increasing of their molecular weight, favorable reaction temperature was-20 ℃. Characterization of the product include 1HNMR, 13CNMR, GPCand DSC, comparing with the homopolymer PSand PMMA, the copolymer has a lower glass temperature.
    Microemulsion Seeded Polymerization of Styrene
    XU Xiang-Ling, ZHANG Zhi-Cheng, WU Xin, GE Xue-Wu, ZUO Ju, NIU Ai-Zhen
    1998, 19(7):  1166-1170. 
    Asbtract ( )   PDF (525KB) ( )  
    Related Articles | Metrics
    Microemulsion seeded polymerizations of styrene were studied with γ ray or potassium persulfate. After examining the size of polymer particles and its distribution before and after polymerization, it was found that there were no new particles formed during polymerization, despite that there were micelles in aqueous phase. These micelles acted as monomer reservoir during polymerization, instead of nucleating loci. Due to the lower monomer content and the much more polymer particles in microemulsion seeded polymerization, its polymerization behavior was much different from the emulsion seeded polymerization.
    Preparation of Polyaniline Doped with Different Organic Acids from Precipitation Polymerization
    MA Yong-Mei, XIE Hong-Quan, WANG Song-Lin, FENG Ding-Song
    1998, 19(7):  1171-1174. 
    Asbtract ( )   PDF (1286KB) ( )  
    Related Articles | Metrics
    Polyanilines doped with different organic acids were directly prepared by precipitation polymerization technique using water/acetone as the medium of reaction and dodecylbenzene sulfonic acid (DBSA) or dibutylnaphthalene sulfonic acid(DBNSA) as the organic acid. Optimum reaction parameters, such as polymerization temperature, reaction time, molar ratio of acid/aniline and (NH4)2S2O8/aniline, were obtained for the precipitation polymerization of aniline. Polymer yield was about 80%. Organic acid doped PAn made in 2L experiment scale showed a high conductivity (3.0 S·cm-1) and can be easily dissolved in common organic solvent, therefore, this precipitation polymerization technique should be applied in industry. PAn DBNSAis somewhat better than PAn DBSA in properties.
    Studies on Carbosillane Liquid Crystalline Dendrimer with SC*Phase
    ZHANG Qi-Zhen, SUN Ji-Run, WANG Da-Qing, WANG Yan, LI Guang
    1998, 19(7):  1175-1177. 
    Asbtract ( )   PDF (350KB) ( )  
    Related Articles | Metrics
    A liquid crystalline carbosilane dendrimer with SC*phase has been synthesized in successive steps, resulting in the formation of defined, unimolecular compound. Twelve biphenyl mesogenic units were attached on its periphery and it has a three dimentional, tree like starburst structure. Its phase behavior was K95Sc*103Ch118I. Compared with its biphenyl mesogenic unit, 4-(2′-methylbutyl)-4′-(ω-hydroxyhexyl)azobenzene, which was melted at 128 ℃ and is not a liquid crystal, it is a good liquid crystal material with S C*phase.
    A Kinetic Study on Ethylene Polymerization by Cp2ZrCl2/iso-Butylalumoxane
    FAN Zhi-Qiang, WENG Jian-Hua, WANG Qi, FENG Lin-Xian
    1998, 19(7):  1178-1180. 
    Asbtract ( )   PDF (159KB) ( )  
    Related Articles | Metrics
    iso-Butylalumoxane(BAO) has been synthesized and characterized, and ethylene polymerization catalyzed by Cp2ZrCl2/BAO has been investigated. The polymerization rate curves at different catalyst concentrations, Al/Zr molar ratio and polymerization temperature are determined and compared to the kinetic behavior of ethylene polymerization catalyzed by Cp2ZrCl2/methylalumoxane(MAO) reported in literature. On the basis a tentative model for the cocatalytic action of BAO has been proposed: only a kind of multi molecular aggregates of BAO can act as cocatalyst of metallocenes. Because of the low stability of the BAO aggregates, Cp2ZrCl2/BAO system shows a moderate catalytic activity only at relatively high BAO concentration and medium temperature. The main reason for the lower activity of BAO than MAO is the absence of highly active species which is stable at low concentration and high temperature.
    Studies on the Mechanism of the Initial Dark Oxidation of Ethers
    ZHU Jun-Min, CAO Wei-Xiao, FENG Xin-De
    1998, 19(7):  1181-1183. 
    Asbtract ( )   PDF (956KB) ( )  
    Related Articles | Metrics
    The contact charge transfer (CCT) complexes of isopropyl ether, phenyl isopropyl ether and benzyl isopropyl ether with O2were measured. It was found that the oxygenative position of isopropyl ether is different from that of phenyl isopropyl ether and benzyl isopropyl ether due to benzene ring in their structures. In the former the oxygenative position is at the etheroxy bond while in the latter at the benzene ring. The mechanism of the initial dark oxidation of ether was proposed.
Special Issues
More...
Download
More...
Links
More...