Table of Content

24 October 1991, Volume 12 Issue 10

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Articles

Preparation and Characterization of Potassium Heteropoly-molybdophosphate of the Lanthanide Elements

Wang En-bo, You Wan-sheng, Liu Jing-fu, Hu Chang-wen

1991, 12(10):  1279-1283. 

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The preparation and the physical and chemical characterization of K₁₇[Ln(P₂Mo₁₇O₆₁)₂]·xH₂O(Ln=La,Ce, Pr, Nd, Sm, Eu, Gd, Tb, Yb) are reported. The test of cation bedexchanger shows that the lanthanide cations are interior. Complexes [Ln(P₂Mo₁₇O₆₁)₂]^17-are stable in the solution of the pHrange 3. 2-5. 5. IRspectra show that the ligand is α₂-PaMo₁₇O₆₁^10-, and the lanthanide cations are octahedral coordination. It is inferred that the complexes resemble the K₁₇[Ce(Ⅳ) (α₂-P₂W₁₇O₆₁)₂] ·xH₂O in structure. The UVspectrum, polarogram, CV, magnetic susceptibility and thermal stability of the complexes are studied. Also the properties of the complexes are discussed from the structure.

Studies on Complexes of the Rare Earth with the Bidentate Heterocyclic Amine Ligands(Ⅲ)--The Synthesis, Property and Crystal Structure of Complexes of Lanthanides Trichloroacetate with Two α,α'-Bipyridine

Wang Jun-rei, Dong Nan, Wu Guang, Zheng Pei-ju

1991, 12(10):  1284-1288. 

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This paper presents the syntheses of the series complexes of lantnanides (except Pm) trichloroacetate with two α,α'-bipyridine from the mixed solvent of water and organic solvent, their properties were characterized, and the crystal structuer of Pr(TCA)₃(bipy)₂ was determined.

Preparation and Structural Characterization of Lanthanum Hydroxide Hydrogen Diphthalate Monohydrate

Sun Ju-tang, Yao Song-nian, Du Xiu-zhen, Chen Sheng-yun

1991, 12(10):  1289-1292. 

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The LaOH(C₈H₅O₄)₂·H₂O was prepared by employing water film reaction method. The electron and X-ray diffraction patterns show that the complex belongs to a monoclinic system, Plal, Z=4, α=2. 0587 nm, b=0. 6235 nm, c=1. 3113 nm, β=94. 64°. The IRspectrum was recorded with a FT-IRspectrometer, and the vibrational bands were assigned by comparison with that of calcium phthalate monohydrate. The coordinate structure of carboxylate groups with lanthanum ions was discussed.

Liquid-Solid Extraction System of Polyethylene Glycol 2000-Tween80-(NH₄)₂SO₄-H₂O

Li Bu-hai, Qu Ying-jun, Li Pu-yuan

1991, 12(10):  1293-1296. 

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In the presence of (NH₄)₂SO₄the aqueous solution of the mixed polymers of polyethylene glycol (PEG)2000 and Tween 80 can be separated into liquid and solid phases. The conditions for the phase separation were found. The distribution behaviour of water-soluble ligands and their metal chelates between the two phases was studied. The quantitative extraction separation of Zr(Ⅳ)-Sc (Ⅲ) and Fe(Ⅲ)-Sc(Ⅲ) was achieved. The extraction mechanism for the phase of the mixed polymers was tentatively discussed.

Studies on Complex of Copper (Ⅱ) α-Methylacrylate with 2,2'-Bipyridine

Wang Yao-yu, Gao Yi-ci, Zhu Ying, Shi Qi-zhen

1991, 12(10):  1297-1299. 

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A detailed synthesis is described for complex of copperα-methylacrylate with 2,2'-bipyridine. Elementary analysis, thermal analysis, conductivity data, susceptibility, IRand UV-vis spectra indicate the complex as [Cu(CH₂=C(CH₃)COO)₂(bipy)(H₂O)]. The molecular structure of the title compound was determined by single crystal X-ray diffraction. The crystal is a monoclinic and the lattice parameters are: α=0. 6851(1) nm, 6=1. 7626(2) nm, c=1. 5553(1) nm,β=96. 52 (1)°.

A Study of Nafion Schiff Base Modified Electrode

Wu Qing-guo, Liu Kuai-zhi

1991, 12(10):  1300-1303. 

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This paper describes the preparation of the glassy carbon electrode treated with Nafion-130 containing Schiff base and the process of electrochemical response. It was proved that mercury ions can be complexed with Schiff base, which is verified by IRspectral analysis. The Nafion-Schiff base coated electrode was used to determine trace mercury, and improved the resistance to interference from surface active compounds and increased sensitity. The result was satisfactory when the NSCME was used to determine trace mercury in untreated urine sample.

The Investigation of a Fiber Optical Aluminum Sensor Using Poly (Vinyl Alcohol) Gel as a Substrate

Ma Wang-bai, Zhang Zhu-jun

1991, 12(10):  1304-1307. 

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An optical sensor responding to Al(Ⅲ) was prepared by covalently coupling morin to poly (vinyl alcohol) via cyanuric chloride. The fluorescence was measured at 490 nm with excitation at 410 nm. The steady-state intensity is reached in 5-10 s, when aluminum ions is added to acetate buffer with pH4. 8. The calibration graph is rectilinear from 3×10^-7mol/Lto 10^-4mol/L. The detection limit is 2×10^-7mol/L. The effects of pH, the amount of immobilized morin and various foreign ions have been studied. The method has been applied to the determination of Al in top water. The results are in good agreement with those obtained by AAS of Al determination.

Determination of Naphthalene, Phenanthrene, Pyrene and Fluorene in Mixtures with Generalized Rank Annihilation-Fluorimetry

Gang Pei sheng, Li Tong-hua, Zhang Jun-yan, Gu Zhi-cheng

1991, 12(10):  1308-1311. 

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Here is a new generalized rank annihilation strategy by which the application of principal Component analysis to the calibration and prediction samples is performed. The number of principal components are determined according to the percentage of a eigenvalue in the total sum of eigenvalues acquired in the singular-value decomposition. This strategy was used to quantitatively analyze the multinuclear aromatic hydrocarbon mixtures consisting of naphthalene, phenanthrene, pyrene and fluorene by fluorimetry. The influence of the number of pricipal components is discussed and the averaged percent error of prediction is <8% and the largest error is about 13%.

Investigation of Linear Sweep Voltammetry(Ⅰ)--The Equation of Quasi-Steady-State Reversible Wave at the Microdisk Electrode and Its Experimental Verification

Zhang Zu-xun, Wang Xiao-ping, Wu Zhi-bin

1991, 12(10):  1312-1315. 

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An approximate expression for guasi-steady-state reversible wave at the microdisk electrode is derived in the following form. i = 4nFD_RT₀C_R^*∫(P)θ/(1+θ), where i is the current, D_Rthe diffusion coefficient, T₀the radius of the electrode, C_R^* the bulk concentration, P=(nFT₀²v/PTDR)^1/2 and θ=exp[nF(E-E⁰)/RT], the equation holds for P<1. In order to examine the validity of the equation, experimental studies with Fe(CN)₆^4-ions in 0. 5 mol/L KCl solution were carried out at the platinum disk (r₀=29. 9 μm) electrode. The experimental voltammograms are in good agreement with the theoretical ones.

Studies on Determination of Carbohydrate by Oxidation on Glassy Carbon Electrode in Basic Solutions

Hu Xiao-ya, Leng Zong-zhou, Wang Cheng-yin, Wu Ning

1991, 12(10):  1316-1319. 

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The determination of carbohydrate, such as glucose, fructose, maltose, lactose, sucrose, glycerol etc. was carried out with glassy carbon electrode by constant potential oxidation (0. 75 Vvs. SCE) or potential sweep oxidation(0. 2-0. 75 V) in 0.1 or 0. 2 mol/L NaOH solution. The lowest detection limit is 1 μg/mL, Abetter repeatability and long useful lifetime are obtained. The detection range of glucose is 0.1-5×10^-6mol/L. The response mechanism is discussed in this paper.

Application and Current Response of Electrochemical and Immobile Polypyrrole Cholesterol Oxidase Electrode

Lou Yin-hua, Zheng Dong-sheng, Zhang Rong-kun, Wang Jin

1991, 12(10):  1320-1322. 

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This article reports a new kind of PP/GOX/cholesterol oxidasemodifidd electrode. In the presence of enzyme, pyrrole was electrolysed and precipitated, its monomer was electrochemically oxidized and polymerized to form membrane which carries positive charge. In the process of membrane formation, the anion entered the membrane. After studying the electropolymerizing conditions, the electrochemical behaviour and other properties of this electrode, we found that in order to improve measuring sensitivity and accuration and reduce working potential and diminish background current, Mo⁶⁺should be added to the solution, the catalyst I^-is oxidized by H₂O₂to form I₂, then, the existence of cholesterol can be determined by measuring the reduced current of I₂.This method can be applied to measuring tolly cholesteol and the result is satisfactory. Manufacturing this kind of electrodes is significant for modified electrode miniaturization and living body analysis.

Mechanism of Atomization on the Graphite Probe Surface in Graphite Furnace (Ⅴ)--Mechanism for Atomization of Manganese

Wang Jian-ping, Deng Bo

1991, 12(10):  1323-1325. 

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The mechanism of atomization for Mn compound on the graphite probe surface in graphite furnace was investigated by using X-ray diffraction spectrometry(XRD), Auger electron spectroscopy (AES) and electron spectroscopy for chemical analysis (ESCA). Gaseous Mn atoms originated from the thermal dissociation of its monooxide on the graphite probe surface at relatively high temperature.

Synthesis of 1-[5-(α-Naphthyl)-2H-Tetrazol-2-Acetyl]-4-Aroylthiosemicarbazides and 3-[5-(α-Naphthyl)-2H-Tetrazol-2-Methylene]-4-Aroyl-1, 2,4-Triazoline-5-Thione Derivatives

Feng Xiao-ming, Chen Rong, Zhang Zi-yi

1991, 12(10):  1326-1330. 

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A series of new 1-[5-(α-naphthyl)-2H-tetrazol-2-acetyl]-4-aroylthiosemicarbazides(Ⅱ) weresynthesized by condensation of aroylisothiocyanate with 5-(α-naphthyl-2H-tetrazol-2-acetylhydrazine(Ⅰ) in absolute acetonitrile. Some of 3-[5-(α-naphthyl)-2H-tetrazol-2-methylene]-4-aroyl-1,2,4-triazoline-5-thione(Ⅲ) were prepared by the cyclization of compounds(Ⅱ) under the catalysis of 1 mol/L K₂CO₃solution. The structures of all compounds prepared were characterized by elemental analysis, IR and ¹HNMR. The regioselectivity of the cyclization of compounds (Ⅱ) was rationalized with the fragments of mass spectra of compounds (Ⅲ).Preliminary pharmacological examinations show that the new compounds (Ⅱ) and (Ⅲ) possess some promoting, or inhibiting activity on growth of plumule of wheat.

Spherical Copolymer as a Column Packing for Reversed-Phase Liquid Chromatography

Zuo Yu-min, Li Ai-min, Xuan Guang-shan, Gui Ming-de, Yang Xue-jin

1991, 12(10):  1331-1334. 

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The spherical copolymer of ethylstyrene with divinylbenzene for using as the packing material for Reversed-phase-HPLC has been prepared by a novel polymerization process. The 95% particle sizes of the polymers are within 3-7 μm. Some column parameters such as the permeability, efficiency and peak asymmetry were calculated. The excellent characters of this packing material for the separation of mixtures of amines, phenols and aromatic hydrocarbons were well demonstrated through several examples.

Studies on the Structures of Cyclo-posphonodipeptides Containing O-P-N Group

Chen Ru-yu, Deng Shi-xian, Cai Bao-zhong

1991, 12(10):  1335-1337. 

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In this paper, the geometrical isomers of cyclophosphonodipeptides were separated and the numbers of those isomers were determined by high resolution ¹H NMR and other spectroscopic methods. Their structures were determined by X-ray diffraction. It was found that among the isomers the phenyl group at phosphorus atom and the substituents at its a-carbon atom were cis to each other, the cyclohexyl rings of the four products were all in twist boat form.

Syntheses of 1,2,3,4,5-pentamethylcyclopentadienyl-organochlorosilanes

Shi Bao-chuan, Jutzi P.

1991, 12(10):  1338-1340. 

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1,2,3,4,5-pentamethylcydopentadienylorganocMorosilanes(2-7) have been prepared by the reaction of pentamethylcyclodienyl lithium with organochlorosilanes, and their elemental analysis, ¹H, ¹³C and ²⁹Si NMR, and MShave been determined.

Syntheses and Surface Active Properties of Polyoxyethylene Fatty Alcohol Ether Sulfonates

Shi Ming-li, Ding Zhao-yun, Wang Zhong-ni

1991, 12(10):  1341-1343. 

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Syntheses and surface active properties of the polyoxyethylene fatty alcohol ether sulfonates were studied. The results show that the introduction of the three oxyethylene groups (OE) in the fatty alcohol sulfonates is more surface-active in aq. solutions than those with one OEor two OE.

Studies on Condensed Heterocyclic Compounds (Ⅳ)--Synthesis and Antibacterial Activity of 5-Formylamino-l-Aryl-1,2,3-Triazolo(2,3-d)Pyrimidin-4 one and Their Related Derivatives

Zhang Zi-yi, Liu Ying, Yang Shi-yan, Chen Mao-qi

1991, 12(10):  1344-1346. 

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5-Formylamino-1-aryl-1,2,3-triazolo(2, 3-d)pyrimidin-4-one (4_a,b,c) and 5-amino-6-hydroxyl-7H-1-(m-nitrophenyl)-1,2,3-triazolo(2,3-d)pyrimidin-4-one (5_d) have been synthesised fromthe reaction of 1-aryl-4-carbonhydrazide-5-amino-1, 2, 3-triazoles 3_a,b,c,dprepared by hydrazinolysis of either 1-aryl-4-ethoxycarbonyl-5-amino-1, 2, 3-triazoles 1_a,b,c,dor their benzoylamino derivatives (2_a,d), with an excess of formic acid under the fluxing condition. The structures of all heterocyclic compounds were confirmed by elemental analysis, IR,¹HNMR, MS, and the inhibiting effects on B. Substilis; E. coli; E. aerogenes;S. aureus were also screened.

Studies on the Insect Sex Pheromones (Ⅵ)--The Synthesis of 4,8-Dimethylheptacosane, a Component of House Fly Sex Pheromones

Liu Tian-lin, Chai Sheng-yong, Li Zheng-ming

1991, 12(10):  1347-1349. 

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4, 8-EHmethylheptacosane, a component of house fly (Musca domestica L.) sex pheromones, was prepared from the starting material 2-methylpentan-l-ol by bromination, Grignard reaction, PCCoxidation, Wittig reaction, and hydrogenation.

A Novel Approach to the Synthesis of Derivative of 6-Acetyl or 7-Acetyl Lumazine Ring Systems

Song Yan-ling

1991, 12(10):  1350-1352. 

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Six compounds containing lumazine ring were prepared by the reaction of 4,5-diamino-2,6-dihydroxy-pyrimidine and its derivative with the 2,3, 4-pentanetrione, respectively. Among them, four are new compounds. The structures of these products were proved by ¹HNMR, MS spectra.

A Theoretical Study of Hyperconjugation of Propene and Methylbenzene

Mo Yi-rong, Wang Nan-qin, Zhang Qian-er

1991, 12(10):  1353-1356. 

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Two hyperconjugated systems, propene and methylbenzene were studied with ab initio method. The result shows that when a methyl participates in the hyperconjugation, the TC-His lengthened and the population of His decreased. The rotation barriers of propene and methylbenzene are 7. 61 and 0. 096 kJ/mol, respectively. The hyperconjugated radical can be considered as a mixed atom with a lone electron pair.stabilities of these configurations can be characterized by.

Thermodynamic Properties of Microemulsion Composed of Nonionic Surfactants(Ⅱ)--The Effect of Alkyl Chain Length of Alcohol and Oxyethylene Unit of Nonionic Surfactants

Hao Ce, Shi Cai-yun, Chen Zong-qi, Xiao Gui-shi, Song Jiu-wei, Cheng De-shu

1991, 12(10):  1357-1360. 

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The Microemulsions composed of nonionic surfactants are a quaternary mixtures consisting of polyphenol oxyethlene ethers, oil (toluene), water and alcohol (hexanol). The systems were studied thermodynamically by means of dilution to determine the standard free energy for alcohol to tranfer from the oil phase to the interfacial region. From the effects of temperature, the entropy and enthalpy were calculated. The effect of chain length of the alcohol is described. It is found that the thermodynamic functions change linearly with the increase of the number of carbons (n) in the alcohol, which can be described as-AGs→△G_s→i⁰=6860+224n(35℃)△H_s→i⁰ = 92300-6700n and △S_s→i⁰ = 321-21n.

Quenching of Pyrene Fluorescence in the Micellization Process of Some Ionic Surfactants

Jiang Yun-bao, Xu Jin-gou, Chen Guo-zhen

1991, 12(10):  1361-1364. 

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The quenching of pyrene fluorescence in the micellization process of alkyltriphenylphosphonium bromide and N-alkylpyridinium bromide is described. It is found that the fluorescence quenching obeys the Stern-Volmer equation, the surfactant with a longer alkyl chain has a larger quenching constant before the formation of micelle, and the quenching constant before the formation of micelle is lower than that after the formation. Ajump is noted in the Stern-Volmer curve before and after the formation of micelle and the critical micelle concentrations of the studied surfactants accordingly obtained are consistent with the reported values. The preferential configuration of surfactant molecule in aqueous solution and the solubilization position of pyrene in micelle are discussed. Also included is a brief discussion of the mechanism of micelle enhancement of luminescence analysis.

Preparation of Poly (vinyl butyral) LB Film and Its Improvement on Cadmium Stearate LB Film

Mu Jin, Xiao Tong, Sun Lai-sheng, Yang Kong-zhang

1991, 12(10):  1365-1365. 

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The surface pressure-area isotherm and stability of Langmuir film of poly (vinyl butyral) have been studied and its LBfilm has successfully been deposited. It was found that an alternating hetero LBfilm of cadmium stearate bilayer and poly (vinyl butyral) bilayer can improve the optical quality of cadmium stearate LBfilm, and covering the cadmium stearate LBfilm with poly (vinyl butyral) LBfilm can maintain the cadmium stearate LBfilm structure.

The Boundary and Size Effects of Repeated Unit Systems

Li Jia-bo, Yang Zhong-zhi, Tang Ao-qing

1991, 12(10):  1369-1372. 

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Based on factorizing of HMO eigene quatior., a new method dealing with the boundary and size effects of the repeated unit systems is developed in the frame work of Huckel theory. By using the computer program of this method, we have calculated the bond order and free valence of some repeated-unit systems with various sizes (up to 1600 atomic orbitals), and the boundary and size effects are also revealed.

The Synthesis and Characterization of Molybdophosphoric Acid with Dawson Structure

Wu Tong-hao, Li Jian-qing, Yang Hong-mao, Wang Guo-jia, Zhang Heng-bin, Wei Quan, Jiang Yu-zi

1991, 12(10):  1373-1377. 

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The molybdophosphoric acid with Dawson structure and its tetrabutylammonium, tetrabutylphosphorium salts were synthesized. Their purities were checked by IR, ³¹PNMR and cyclic voltammetry, and their thermal stabilities, acidities and redox properties were also studied. The results ' show that the molybdophosphoric acid with Dawson structure should have stronger oxidizability than that with of the acid Keggin one.

Catalytic Oxidation Properties of Dawson and Keggin Structure Molybdophosphoric Acids

Wu Tong-hao, La Jian-qing, Wang Guo-jia, Yang Hong-mao, Zhang Heng-bin, Wei Quan, Jiang Yu-zi

1991, 12(10):  1378-1381. 

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In the present work, we examined the catalytic oxidation activities of Dawson and Keggin structure molybdophosphoric acids and related the results with the structureal characteristics. The results show that Dawson structure heteropoly acids have higher activities to either oxidative dehydrogenation reaction or oxygen addition reaction.

A NMR Study of the Reaction Between cis-Diaquodiammine-platinum(Ⅱ) and Biomembranic Phospholipids

Wang Kui, Liu Dong, Zhuo Ji-cang

1991, 12(10):  1382-1385. 

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By means of NMR method, the modes and effects of the interaction between cis-diaquodiammineplatinum(Ⅱ) (AAP) and α-dipalmitoylglycerylphosphatidylcholine (DPPC) were studied to clarify the contribution of phospholipid-platinum reaction to the cisplatin-cell interactions. ¹H and ¹³C spectra show that in CDCl₃, as the result of DPPC-AAP reaction, the platinum binds to the head group of DPPC and induced a gauche to trans transformation in the glycerol moiety. The ¹H T₁ values of -N(CH₃)₃⁺,-(CH₂)_n- and -CH₃of DPPC in liposome form were determined at 65℃ after the reaction with AAP in D₂O for different time. The results indicate that the conformational change of phospholipid molecules and the changes in the set-up of the membranic molecules induced by the platinum binding may contribute to the cisplatin-cell interaction and are relevant to the anticancer activity and toxicity of cisplatin.

XPS Study on Rare Earth Complexes with L-Glutamine

Niu Chun-ji, Zhang Shu-gong, Wang Zeng-lin, Ni Jia-zuan, Nie Yu-xiu, Yin Xin, Xu Yi-lu

1991, 12(10):  1386-1389. 

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The title complexes with a composition LnL₃Cl₃· 2H₂O(Ln=Eu,Tb,Ho and Tm; L=L-glutamine) were synthesized and characterized by XPS combined with elemental analysis, thermal analysis and IRspectra. The change of binding energies of O_1a, Ln_3d, Ln_4dand Cl_2p, took place obviously because of the coordination, and the satellite peaks appear in XPS3d spectrum of Eu complex. The mechanism of formation of satellite peak is discussed.

The Study on Segment Motion of Drag Reduction Agents of Crude Oil Using 2,2,6,6-tetramethylpiperidone as Spin Probe

Wang Li, Feng Lin-xian, Mao Qing-ge, Yang Shi-lin

1991, 12(10):  1390-1392. 

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The segment motion of drag reduction agents of crude oil is considered to correlate to drag reduction efficiency. In this paper, 2,2,6,6-tetramethylpiperidone was used as a spin probe. The ESR spectra of probe were recorded at different temperatures and the values of T_50Gwere calculated. It was discovered that the lower the T_50G, the higher the drag reduction efficiency.

Preparation of PbS Ultrafine Particles and Study of Quantum Size Effect

Li Shou-tian, Zou Bing-suo, Zhang Yan, Xiao Liang-zhi, Li Tie-jin, Shi Su-hua

1991, 12(10):  1393-1394. 

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In this paper we report the preparation of monodispersed lead sulfide ultrafine particles and their absorption spectra. The evident structures and blue shifts of the absorption spectra are observed. The results obtained are discussed by quantum size effect.

An Ab initio Study on the Molecular Structures of CX₃NO(X=H,F,Cl)

Wu Nian-ci, Dong Nan, Cai Guo-qiang, Yu Qing-sen

1991, 12(10):  1395-1397. 

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The stabilities of the molecular structures of CH₃NO, CH₂FNO, CHF₂NO, CH₂ClNO, CHCl₂NO, CHFClNO, CF₃NO and CCl₃NO was studied at minimal basis set(STO-3G) by complete optimization and the rotation potential barrier of CF₃NO at the extended basis set(4-31G). The quite satifactory results have been obtained.

A Study of the Spectrum and the Cubic Zero-field Splitting of Mn²⁺ Ions in Six and Eight Ligand O_hSymmetric Crystal Field

Wang Bao, Ning You-ming, Zhao Sang-bo

1991, 12(10):  1398-1399. 

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A group of complete, strong-field-energy matrices for the perturbed Hamiltonian H' of the d⁵ ion system are constructed by using the Oh group representation strong field scheme. From this, we have successfully obtained a unified theoretical explanation of the spectrum and the cubic zero-field splitting of the ground state of Mn²⁺ions in eight-ligand system (CaF₂) and six-ligand system (KZnF₃. RbCdF₃) for the first time. The calculated values are in good agreement with the observed result.

Oscillating Phenomena in 3,4-Dihydroxybenzoic Acid-BrO₃--Fe(phen)₃²⁺-H₂SO₄System

La He-xing, Jiang Ping-chu, Xu Hai-han

1991, 12(10):  1400-1402. 

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Anew oscillating system. 3,4-dihydroxybenzoic acid-BrO₃--Fe(phen)₃²⁺-H₂SO₄system was studied in detail. The role of bromide ion in the oscillation was investigated. The initial addition of bromide ion to the system produced a variety of phenomena depending on the initial bromide concentration. In certain range concentration of bromide, the system displays two types of oscillating waves, one is a low-frequency oscillating wave and the other is a high-frequency oscillating wave. Both of these oscillations are controlled by bromide ions. When bromide concentration is lower than 2. 3 ×10^-3mol/L, only low-frequency oscillating wave appears, and when bromide concentration is more than 2. 9×10^-3mol/L, only high-frequency oscillating wave appears. The role of bromide in this system was analyzed and the mechanism of bromide in the oscillation was proposed.

The Influence of Ligand Oxygen Atom on the Electronic Structure of 7-Chloro-4-Quinolinol Structural Unit

Hou Dong-yan, Gao Zhi-ming, Wu Tong-hao

1991, 12(10):  1403-1404. 

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It has been found that the 7-chloro-4-quinolinol N-oxide is an anticancer drug, while 7-chloro-4-quinolinol is not anticancerous. In order to understand the difference between their electronic structures, we have performed M1NDO/3 optimization and INDO/1+Cl calculations. It was found that the theoretical results are highly consistent with the experimental data. Especially, the transition mechanism of electronic spectra was revealed.

The Effect of Magnetic Field on the Coagulation of Ni-Contained Wastewater

Huang Zi-qiang, Chen Li-gen, Yang Yan, Zhu Chuan-zheng

1991, 12(10):  1405-1406. 

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The effect of magnetic field on the treatment of Ni-contained wastewater was studied. It is found that the magnetic treatment can intensify the process of coagulation and sedimentation of wastewater. The intensification is relative to the treatment method, field strength and treating time in the magnetic field.

Grafting Copolymerization of Acrylonitrile on Polyacrylamide Initiated by Potassium Diperiodatocuprate (Ⅲ)

Liu Ying-hai, Son Xing-ru, Liu Bao-qi, He Su-zhen, Zhang Yun-xiao

1991, 12(10):  1407-1410. 

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The graft copolymerization of acrylonitrile (AN) onto polyacrylamide (PAAM) was studied by using potassium diperiodatocuprate (Ⅲ) as the initiator. It was found that potassium diperiodatocuprate-PAAMcomplex is an efficient redox initiator for the graft copoiymerization. The effects of the temperature, concentration of initiator and monomer (AN) on the reaction were investigated. Under the optimum conditions the efficiency of graft exceeds 95% and the graft percent of PANin copolymer reaches 80%. The initiation mechanism is proposed.

The Study of Photoelectrochemical Polymerization of Thiophene

Cai U-fen, Chen Yan-zhen

1991, 12(10):  1411-1413. 

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In aqueous acidic solutions, thiophene undergoes low polymerization at first, and then the low polymer can be oxidized to form a film. The light can promote the low polymer formation. The thiophene can be selectively photoelectropolymerized on substrates, such as Pt, Au. Apolythiophene film with clear light-points can be formed below the threshold of voltage for electropolymerization of thiophene under normal condition.

Studies on Polymerization of a-Pinene Initiated by a New System AlCl₃/Activator/Donors (Ⅰ)--AlCl₃/SbCl₃/Ester Initiating System

Deng Yun-xiang, Lin Hua-yu, Higashimura T.

1991, 12(10):  1414-1417. 

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The new initiating system AlCl₃/A/D (Aas the activator, modifier and complex agent for Aids; Das the donors) for the polymerization of a-pinene was studied. It was found that some of these initiating systems have a high activity for cationic polymerization of a-pinene and give a good yield of a-pinene resin with high molecular weights. For example, the AlCl₃/SbCl₃/ethyl benzoate (EB) initiating system gives the yield 87. 3% of resin with S. P. 128, 8℃ in toluene at-15-25℃.In this paper, the kinetic behavior of these initiating systems and the characteristic of polymerization products are studied. The effects of various donors, the amount of SbCl₃added, solvents, temperatures and concentrations of EB, initiator and monomers on the polymerization of a-pinene are investigated.

The Sol-Gel Distribution and Gelatinization Region of A_a-B_b(B′)_bType of Polycondensation

Yang Li-ting, Jiao Wen-cheng, Hu Fa-xian, Wang Feng-li

1991, 12(10):  1418-1419. 

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The theory of sol-gel distribution and gelatinization region is a powerful tool for dealing with the structure of crosslinking networks in the molecular level in the classical theory. The present paper covers the sol-gel distribution and gelatinization of A_a-B_b(B′)_btype of polycondensation and the q_b'-S equation obtained from T_b' =T_bS_a/S_b. The experimental results with polyester as the model compound supports the theoretical ones of this paper.