Chemical Research in Chinese Universities

Synthesis and Characterization of Bis(undeca-tungstoferrate) Lanthanates of Potassium

Liu Jingfu, Zong Ruifa, Liang Zhaojun, Wang Enbo, Shen Enhong

1990, 6(3): 165-171.

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Aseries of novel rare earth complexes with 11-tungstoferrate as ligand, K₁₅Ln(FeW₁₁O₃₉)₂xH₂O(Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er or Yb) were prepared and characterized by elemental analyses, IR, UV-vis, polarograms, magnetic susceptibility and thermal measurement.

Studies on Organo-Phosphorus, -Arsenic and -Antimony Polytungstates and Polymolybdates(IX )——Preparation and Properties of o-Aminophenylarsenic Polymolybdates

Liu Benyao, Xie Gaoyang, Yihtong Ku(Gu Yidong), Wang Xin

1990, 6(3): 172-176.

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In order to investigate the influence of organic groups on the types of organoarsenic polymolybdates, o-nitrophenylarsonic acid was reduced to o-aminophenylarsonic acid and then it reacted with sodium molybdate at pH = 3～5. Three new salts were prepared and characterized:(1) (CN₃H₆)₄[(o-NH₂C₆H₄As)₂Mo₆O₂₄], (2) Cs₄[(o-NH₂C₆H₄As)₂Mo₆O₂₄], (3) [(CH₃)₄N]₄[(o-NH₂C₆H₄As)₂Mo₆O₂₄]·2H₂O. The IR, UVspectra, thermal properties and electrochemical behaviors are reported. It is strange enough that when the o-nitro group was reduced to o-amino group, [(RAs)₂Mo₆O₂₄]^4- type of complexes was formed.

A Study on the Determination of Copper by Microwave Induced Plasma Atomic Emission Spectrometry (MIP-AES)

Zhang Hanqi, Yu Shirong, Zhang Xiaohui, Lu Hui, Jin Qinhan

1990, 6(3): 177-182.

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The determination of copper by MIP-AESwas investigated in detail. Aqueous samples were introduced from an ultrasonic nebulizer and the solvent was removed by a desolvation device before introduction of the aerosol into the MIP. The desolvation system consisted of a condenser associated with a concentrated H₂SO₄ absorption cell. Various experimental conditions and interferences from easily ionised elements (EIEs) were also studied and some practical samples were analyzed.

Complexation Properties and Synthesis of 1,2-Bis(2,2'-bipyridinyl)ethylene and 1,2-Bis(2,2' -bipyridinyl)ethane Ligands with Cu(I)

He Yongbing, Lehn Jean-Marie

1990, 6(3): 183-187.

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l,2-Bis(2,2'-bipyridinyl)ethylene(1) ligand was synthesized by Wittig-Horner reaction and 1, 2-Bis(2, 2'-bipyridinyl)ethane(2) ligand(which can be obtained via another route ) was prepared by hydrogenation of (1). The formation of complexes of (1) and (2) with copper (I) has been studied. The influence of the different bridge chains (CH=CH, CH₂CH₂) on complexation is discussed on the basis of ¹H NMR spectra.

Theoretical Study on Dehydrogenation Reactions of Silanol

Han Yunzhu, Zhao Chengda

1990, 6(3): 188-193.

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The pathway of dehydrogenation reaction of silanol SiH₃OHis investigated by ab initio Mo calculations using RHF/-31Gbasis set. The geometries of reactant, transition states and products are optimized on the singlet potential energy surface of the ground state. The activation energies, reaction heats, statistical Afactor and activation entropies are calculated. The vibrational analysis of the reactant and the transition states is made. The reaction crgodography along the intrinsic reaction coordinate (IRC) are performed to examine the reaction mechanism.

EHMO Studies of the Structures and Reactivities of Oxyhemocyanin and Oxytyrosinase Bimiclear Copper Active Sites

Feng Wenju, Guo Ghunxiao, Wei Quan, Liu Yuexian

1990, 6(3): 194-202.

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We have generated one possible active site structure of Oxyhemocyanin (Oxy-Hc) and two possible active site structures of Oxytyrosinase (Oxy-Ty) using the EHMOmethod. Oxy-Hc active site has a plane configuration, while Oxy-Ty has boat configuration. When there exist water molecules, two water molecules are connected with the Oxy-Ty active site weakly. Calculations for the reactions of Oxy-Hc and Oxy-Ty (the water-off) with phenol demonstrate that the former reaction is thermodynamically forbidden, while the latter Is realizable.

Raman Scattering Activities for Uniaxially Oriented Molecules

Wang Jingyuan, Tian Yongchi, Liang Yingqiu

1990, 6(3): 203-209.

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Raman scattering activities were derived for uniaxially oriented molecules. The unique axis of the molecules is assumed to rotate around one of the axes of space-fixed coordinate in a fixed orientation angle with respect to the axis, while the other two principal axes of the molecules are randomly oriented. Expressions for Raman scattering activities in terms of the elements of derived polarizability tensor are given as the function of orientation angle and are tabulated for various symmetries of point groups.

Investigation on Oxidation-Reduction Properties of Some Fe-S and Mo-Fe-S Clusters

Zhang Hengbin, Xu Jiqing, Zhang Hongjie

1990, 6(3): 210-217.

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Oxidation-reduction properties of some Fe-Sand Mo-Fe-Sclusters have been studied by cyclic voltammetric measurement. It is indicated that there are some factors which affect the oxidation- reduction properties of clusters, of which are charge density of metal atom in cluster core, electron effect of ligands, charge and geometric configurations of the reactant particle, etc.

Theoretical Studies on Geometry, Stability and Electronic Spectra of DATB and TATB

Xiao Heming, Yu Hengtai

1990, 6(3): 218-224.

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The geometries of DATB( 1,3-diamino-2,4 ,6-trinitrobenzene) and TATB( 1,3,5-tri-amino-2,4,6-trinitrobenzene) have been optimized by M1NDO/3 method. It is found that the total energy of the molecule is rather low at the plane configuration. It is also found that the orbitals between the amino-Nand its adjacent nitro-Nas well as the amino-Nand its adjacent nitro-Non the ring are rather close and matched in symmetry and have high orbital interaction through space, which are evidently seen from the computed results of the atomic bond index. The electronic spectra of DATBhave been computed by using INDO/2-CImethod, and the results are well conformed with the experimental facts. For instance, the transition from 'A' (ground state" ) to 'A' (the 7th exciled state) corresponds to the computed spectrum line(2.48×10⁴cm^-1) which is close to the experimental value (2.43×10⁴cm^-1). From a similar computation, we may predict that the major spectrum line of TATBwill be 2.75, 2.77, 3.28 and 3.32×10⁴cm^-1.

NMR Study on Fluoroisonucleosides( I)——Determination of the Configuration and Conformation of 1'-a-Methoxy-2' -Deoxy-2' -B-Ruoro-2' -a-Uracil -3' ,4' -o-lsopropylidene-L-Arabinoside

Gao Congyuan, Qiao Hang, Ma Lingtai, Yang Xianbin, Dong Lingjiao, Zhang Lihe

1990, 6(3): 225-228.

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The present paper reports the determination of the configuration and Conformation of 1' -a-methoxy-2' -deoxy-2'-β-fluoro-2'-α-uracil-3',4' -o-isopropylidene-L-arabinoside obtained from silylated uracil by using ¹³C-NMRand 2D-NMR.

Hydrogen Evolution Reaction on Thermodiffusion Treated Nickel-Implanted Titanium Electrodes

Zhang Jishuang, Wang Ronghui, Lu Yaojiao, Yang Jinquan, Feng Hanming

1990, 6(3): 229-230.

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Studies on Chemical Constituents of Thermopsis Licentiana(I)——The Structure of A New Alkaloid

Jia Zhongjian , Song Guangze, Liu Zimin

1990, 6(3): 231-232.

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