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Table of Content

    24 May 1987, Volume 8 Issue 5
    Articles
    Studies on the Quaternary System LiCl-KCl-MgCl2-H2O at 25℃
    Zhang Fengxing, Guo Zhizhen, Chen Peiheng, Ma Jinhua, Chen Yunsheng
    1987, 8(5):  387-392. 
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    The solubilities and the refraction indices, densities and viscosities of the saturated solutions in the title quaternary system have been investigated for the iirst time at 25℃.In the phase diagram there are five crystallization fields corresponding to LiCl·H2O, KCl, MgCl2·6H2O, LiCl·MgCl2·7H2O and KCl·MgCl2·CH2O, respectively. The compositions of the three invariant points are LiCl:44.08, KCl: 3.51, MgCl2:0.65%Wt. (corresponding to KCl+ LiCl·H2O+ KCl·MgCl2· 6H2O); 40.23, 0.62, 5.40 (LiCl·H2O+KCl·MgCl2·6H2O+LiCl·MgCl2·7H2O) and 26.97, 0.15, 14.62 (MgCl2·6H2O+KCl·MgCl2·6H2O+LiCl· MgCl2·7H2O). By using the measured values of the refraction index, density, viscosity, water and chloride ion-content of the saturated solutions of the system, the isograms of these properties are drawn. The iso-density curves intersect with that of the other properties except water-content in a good net form, which may be applied to monitor the isothermal evaporation process of the system quantitatively.
    The Study of the Formation of Zeolite Fe-Si-ZSM-5
    Ma Shujie, Qiu Shilun, Feng Dianying, Xin Minqian
    1987, 8(5):  393-397. 
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    In the course of the crystallization of Fe, Si-ZSM-5 type zeolite with the initial gel composition of 5Na2O·Fe2O2·(20-150)SiO2(800-6000)H2O·(30-100)1,6-HDA we studied the states of existence of Fe3+ions and of polymerization of silicate anions in the solid and the liquid, loss of weight of 1,6-hexadiamine, changes in particle size of solid phase and SiO2in the liquid using ESR,TMS-GC, TG-DTA,electronic microscopy and chemical analysis.
    Studies on Boron Compounds (ⅩⅨ)--New Organyloxy-Diarylborane Chelates Containing virucide 2-(α-Hydroxyalkyl)Benzimidazole as Ligands
    Yuan Guozheng, Li Guiying, Zhang Guomin
    1987, 8(5):  398-402. 
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    Eight new boron compounds were prepared through the reaction of 2-(α-Hydroxymethyl) benzimidazole or 2-(α-Hydroxybenzyl)-benzimidazole with diarylbo-rinic acid. These compounds were identified by elemental analysis, MS, IRand UVspectroscopies.
    Preparation of Tungstic Acid at Room Temperature and Low Acidity
    Jiang Anren, Tang Zeng, Gu Yidong
    1987, 8(5):  403-406. 
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    A new method is described for the preparation of tungstic acid at room temperature (~20℃) and low acidily (~1N) with a high yield (~99%) so it possesses industrial meaning. This method uses H2O2, as a coordination agent, t) react with tungstate forming peroxotungstatc which then is decomposed. Physical proporties of the tungstic acid were studied.
    The Study of the Determination of Trace Silver by Catalytic Kinetics
    Zhang Zhenhui, Zhou Wei, Wen Yining
    1987, 8(5):  407-412. 
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    Anew indicator reaction catalyzed by silver has been studied. When silver is present K4Fe(CN)8reacts with o-phenanthroline in the solution of dilute H2SO4, the mechanism may be represented as follow:Fe(CN)64-+3(o-Phen)AgFe(o-Phen)2(ornge)+6CN-and trace silver could be estimated with the reaction.The apparent activation energies of catalytic and uncatalytic reaction are 64.15 and 96.89 kJ·mol-1, respectively, was calculated by Arrhenius Formula.Compared with other methods, this one is higher sensilivity and selectivity. The sensitivity is 8×10-12g·ml-1.The method has been used for the determination of silver in geological samples with satisfactory results .The average standard deviation of determination is 0.024 and the average coefficient variation 2.43%.
    Analysis of Absorption Data Matrix Using Microcomputer(Ⅰ)--Estimation of Number of Absorbing Species by Rank Analysis
    Liu Yiminn, Yu Ruqin
    1987, 8(5):  413-417. 
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    The absorption data matrices for spcctrophotometric systems were analyzed using microcomputer programs. The rank analysis of absorption spectra was used to estimate the number of absorbing species for binary Fe-CAS system and some ternary systems such as Fe-CAS-CTMAB and Be-CAS-PVPBS with addition of surfactants or polyelectrolytes. It was shown that under the given experimental conditions there exist four absorbing species in the Fc-CAS system and only two kinds of absorbing components were discovered for Fe-CAS-CTMAB system. The decrease of the complex species formed in these systems after addition of surface-active agents is proposed as one of the reasons of the increase of the molar absorptivity caused by these agents.
    Simultaneous Determination of Chlorophyll a and Chlorophyll b by Synchronous Fluorimetry
    Huang Xianzhi, Xu Jingou, Cai Ting
    1987, 8(5):  418-420. 
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    This paper reports a method for simultaneous determination of chlorophyll a and chlorophyll b by synchronous fluorimetry. The scanning wavelength intervals (△λ) of 258nm and 193nm were used and the wavelengths of maximum emission in synchroneous spectra were at 670nm and 654nm for chlorophyll a and chlorophyll b, respectively. This method is simple and rapid, and the ranges of determination were- 0.5-200 ppb. and 0.5-150 ppb, for chlorophyll a and chlorophyll b, respectively. Accuracy of deicrmination was about 5%.
    Syntheses of New Colour Reagent 1-(5'-Bromo-Pyridyl)-5-(4'-Nitro-Phenyl)-3-(2'-Futyl) Formazne and Investigation of Its Colour Reaction with Zinc
    Yang Guifa, Yi Gianhong, Xiang Hong
    1987, 8(5):  421-423. 
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    The synthesis and purification of a new colour reagent l-(5'-bromo-2'-pyridyl)-5-(4/-nitrophenyl)-3-(2'-Furyl ) formazane were investigated. This reagent combines with zinc ions in the presence of nonionic surfactant Twcen-80 in a buffer solution of pH 8.0-10.0 to form a blue-green complex. The complex has an maximum absorption at 688nm with a molar absorptivity of 5.96×104l·mol-1·cm-1. Beer's law is obeyed in the range of 0-4.2μg/10ml for Zn(Ⅱ). The method has been applied to the spectrophotometric determination of micro-amount zinc in ores, with good results.
    Alternating Current Oscillo Potentiometric Titrations on Two Identical Pt Electrodes
    Xu Weijian, Zhang Shengyi, Gao Hong(H. Kao)
    1987, 8(5):  424-426. 
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    Two identical Pt electrodes are put in the titrate. Asmall alternating current is passed through the electrodes which arc connected directly to an oscillograph. Afluorescent line showing the potential difference between the two electrodes appears on the screen. The sudden expand or contract of the line indicate the end point of titration. The end point is very sharp, especially in titration of a reversible titrate with a reversible titrant.
    Analysis of Organometallic Compounds(Ⅶ)--Ultra-Violet Rules of Biscyclopentadienyr Titanium,Zirconium and Hafnium Dichlorides
    Yang Xuejin, Cao Xuemei, Li Zhonghuan, Liang Shusen, Chen Shoushan, Wang Jitao
    1987, 8(5):  427-432. 
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    UV spectra were made for sixty-two bispentadienyl titanium, zirconium andhafnium dihalides. by using 1,2-dichloro cthane as solvent in room . temperature.The absorbancc rules and attributions of the absorption band for these compoundswere presented. The absorption rule of UV spectra, which is presented in thispaper, can be used as a basis for identification of the above three kinds ofcompounds.
    Studies on Nitroxides (ⅩⅥ)--Cyclic Voltammetric Characteristics of Electron Transfer Reaction of Piperidine Nitroxides
    Liu Youcheng, Wu Shuping, Jiang Zhiqin
    1987, 8(5):  433-437. 
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    In this work the electrochemical redox reactions of three piperidine nitroxides (1-3) in methanol were investigated for the purpose of elucidating the mechanism of their electron-transfer (ET) processes. Cyclic voltammctric studies on 1-3 in acidic methanol solution have clearly demonstrated that both electrochemical reduction and oxidation show reversible ETcharacteristics. Both E1/3red and E1/2ox with approximate values of -0.28V and 0.70V respectively, indicate that these nitroxides can be regarded as good models of electron acceptors and donors. It was further found that reduction currents (RC) were considerably larger than oxidation currents (OC) under the same conditions. Moreover, RCincreased rapidly as the acidity of the medium increased, whereas OC decreased slightly with increasing acidity of the medium. These results verify that reduction of 1-3 in acidic nonaqueous solution is expected to procced rapidly and that in weak acidic medium the oxidation of 1-3 should be favored.
    Catalytic Syntheses of Four Uracil Derivatives by Zeolites
    Wang Qiuying, Zhai Yingli, Zhang Wei, Liu Peiqi, Yao Jianshan, Meng Yimin
    1987, 8(5):  438-440. 
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    In this work some kinds of zeolites had been used to catalytically synthesize 1-(chloroacetyl)uracil, l-(2-chloropropionyl)uracil 1-(chloroacetyl)-5-flurouracil, and 1-(2-chloropionyl)-5-urouracil. The syntheses of these compounds were proceeded under room temperature and the purity of various products and yields were very nice. The zeolite catalysts could be reactivated easily.The order of catalytic capabilities was HY>CeY>CaY>HZSM-5>HM.
    A Study on Phase Transfer Catalytic Effects of Polyethylene Glycols in N-Alkylation
    Zhong Qi, Shao Jianguo, Wang Jinhai, Gong Zhengyuan
    1987, 8(5):  441-443. 
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    This paper reports the synthesis of N-alkyl derivatives of phthalimides by using polyethylene glycols(PEG) as phase transfer catalysts. Thirteen N-alkyl phthalimides were obtained by the phase transfer catalytic reactions of phthalimides with corresponding alkyl halides in the presence of absolute potassium carbonate and PEG-400.
    Measurement of Primary Kinetic Deuterium Isotope Effect of the Reaction of Enamine Formation Using Natural Abundance Deuterium NMR
    Kang Guojun, Zhang Benli, Gao Zhenheng(C. H. Kao)
    1987, 8(5):  444-446. 
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    Primary kinetic dculerium isotope effect of the reaction of enamine formation is measured using natural abundance deuterium NMR. The mechanism of this reaction is discussed based on the above measurement. The conclusion is that the step which involved C-Hbond breaking is not the rate-determining
    Studies on Analysis of the Constituents of Schisandra(Ⅱ)--The Structure of a New Constituents Ganwuweizic Acid
    Chen Yaozu, Yue Jianmin, Hua Suming
    1987, 8(5):  447-448. 
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    After we successfully identified 40 constituents of essential oil of Schisandra sphenanthera Rehd, et Wils, collected from District of Wudu, Gansu Province of China, we have isolated four crystalline constituents from its seed. One of these, after recrystallized from ether-n-hexane, was a white plate crystal and melted at 160-161℃. By means of UV, IR, 1HNMR,1CNMR and MS, its structure was proposed as 3-kelo-9,10,19-cyclopropyl-lanost-24-en-26-oic acid. This compound has not been reported in literatures and named as Ganwuweizic acid.
    The V-Coefficients of the I Group-D2Group
    Sun Renan
    1987, 8(5):  449-452. 
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    In this paper, the V-coefficients of the Igroup-D2group are discussed and its values under the single value representations of Igroup are given. Therefore the group link beginning with Igroup may be expanded to D2subgroup of Igroup.Also the calculated values of the V-coefficients about D2group are given.
    The Electrocatalysis of Metalloporphyrins(Ⅵ)--Kinetic Study of Cysteine Oxidation on Heat-treated Cobalt Tetramethoxyphenyl Porphyrin Adsorbed on Graphite
    Deng Zhongyi, Wang Zongli, Li Changming, Zha Quanxing(Cha Chunsin)
    1987, 8(5):  453-458. 
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    The methods of RRDE and cyclic voltammetry have been used to study the oxidation of cysteine on heat-treated cobalt tetramethoxyphenyl porphyrin adsorbed on graphic (Co-TMPP/graphine); Experimental results show that Co-TMPP/graph-ite exhibits signigicant catalytic activity for cysteine oxidation in solutions of different pHvhues. The current efficiency of the cysteine oxidation on Co-TMPP/graph-ite is more than 90%. Cysteine oxidation is a simple charge transfer irreversible reaction on Co-TMPP/graphiic. The standard rate constants (k°) of the cysteine oxiJation were calculated and the reac:ion mechanism of cysteinc oxida-tion were discussed in solutions of various pH.
    Infrared Study of the Property Adsorbed 2,6-Dimethyl-Pyridine on the Several Types of Zeolite
    Dong Yulin, Fong Xusheng, Yang Kongzhang
    1987, 8(5):  459-463. 
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    The property adsorbed 2,6-dimcthylpyridine on the several types of zeolite has been investigated by infrared spectroscopy. The result showed that the stability of adsorption 2,6-dimethylpyridine on the Bronsted and Lewis sites of the same type of zeolite is different, the former is more stable than the latter, and that on the Lewis sites of different types of zeolite is different too, the 2,6-dimethylpyridine are adsorbed specially on the Bronsted sites in the presence of Lewis sites for NaHY at 300-400℃ and for HM, HZSM-5, HZSM-11 at 150-400℃.Competitive adsorption experiments Between pyridine and 2,6-dimethylpyridine on the HZSM-5 show that the 2,6-dimethylpyridine adsorbed on the Lewis sites can be displaced quantitatively by the pyridjne at 150℃.
    The Relation Between the Activity of Catalysts and the Property of Metal Ion in Mutarotation of Glucose
    Liu Fuan, Wei Zhanjun, Huang Huamin
    1987, 8(5):  464-468. 
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    Based on the activity of catalysts for hydrated sulfate in mutarotation of α-D-glucose, it was found that the relations between lgkα,△E, △Sof mutarotation of α-D-glucose and parameters of metal ion are as follows lgkα△E, △S=a(0.05x+0.01y)+b where x=Z1.8/r,y=I(1+aD) Z is pesitive charge of metal ion, r is radius of metal ion in catalysts, Iis tovalent parameter,α is polarizability of metal ion, Dis parameter which depends on the electron configuration of metal ion and the d electron number.
    Gel Permeation Behavior of Ring Shaped PS and Calculation of the Relative Content of the Linear Polymer in Ring Shaped Fractions
    Huang Jiaxian, Chen Guohua, Li Chunrong, Shen Jun
    1987, 8(5):  467-472. 
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    In dilute solutions there are quantitative relationships between the dynamic parameters of the ring shaped and linear polymer coils with the same structural unit and equal molecular weight. In this paper we have developed methods to deal quantitatively with problems concerning the calculation of the relative content of the linear polymer in the ring shaped fractions and the relationship between the elution volume and the parameter gc. The correlative equations gc =exp(-2.303 b△Ve) and (Mw)GPC /(Mw)LS= gcI/(α+1) have been derived and verified by the gel permeation behavior and viscosity study. Finally, the relative content of the trace linear polymer in the ring shaped fractions has been given as WL=(gc'-gc)/[(1-gc1/(a+1))(agc'+gca/(a+1))].
    Study on the Synthesis of Bisphenol-S Polyarylester by Phase Transfer Catalysis Technique
    Li Yingjun, Lin Dehou, Liu Hongshi, Yu Hongze, Wu Zhongwen
    1987, 8(5):  473-477. 
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    In this paper, we reported the experimental results of synthesis of bisphenol-Spolyarylester by phase transfer catalysis technique as well as the monomer preparation. The effect of the same factors on polymerization was discussed. It was shown that it was possible to prepare bisphenol-Spolyarylester with high molecular weight using quaternary ammonium salt as a phase transfer catalysis at 30℃. The bisphcnol-Spolyarylester exhibited excellent transparency, electronic properties, especially mechanical properties even at 150℃. Transmittancy of visible light is 87%, tensile yield stress of room temperature 637 kg/cm2, Tg208℃, dielectric constant 3.6, breakdown voltage 150 kV/mm.
    Studies on the Interaction Between 4,4'-(1,4-Phenylene)-bis-(N-Methyl-2, 6-Diphenyl) Pyridinium Salts and Tetraphenylsulfonic Porphine Zinc
    Cao Weixiao, Li Xouyan, Feng Xinde
    1987, 8(5):  478-480. 
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    4, 4'-(1,4-Phenylene)-bis-(N-methyl-2, 6-diphenyl)pyridinium salts (PMDP) and tetraphenyl sulfonic porphine zinc(ZnTPPS) were prepared and the interactions between. PMDP and ZnTPPS have been investigated preliminary by electron or fluorescence spectroscopic method. It has been found that in ground state the Complexes will form between the molecules of PMDP and ZnTPPS, and in excited state the fluorescence of ZnTPPS will be quenched by PMDP.