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Table of Content

    24 April 1985, Volume 6 Issue 4
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    Articles
    Studies on Thermodynamics of Crown Coordination Compounds(V)—Calorimetric Titration for Coordination Reaction of 2,3-Benzo-11-Methy 1-18-Crown-6 with Alkali and Alkaline Earth Metal Ions
    Shen Mengchang, Luo Qinhui, Wang Zhilin, Lu Guoyuan, Hu Hongwen
    1985, 6(4):  285-289. 
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    The coordination reactions of 2,3-benzo-11-methyl-18-crown-6(BCl-18C6) with eight alkali and alkaline earth (Na,K,Rb,Cs, Mg, Ca,Sr,Ba) chlorides were determined at 30℃ and in 70% W/Wmethanol by self-made titralion calorimeter. The stability constants of coordination compounds and the enthalpy of coordination reaction were calculated directly. Because the space hindrance gives a weaker effect to small metal ions than to large ones, and the space hindrar.ce of crown with only one methyl is weak, the stability sequence of alkali metal coordination compounds is K> Rb>Na≥Cs and is different from that of 2, 3-benzo-8, 11, l5-trimethyl-18-crown-6 (BC3-18C6). Furthermore, the stability constants of (BC3-18C6) coordinition compounds with Mg and Ca are even higher than those of BC1-18C6 pnes because of the small radii of Mg and Ca.
    Calculation of Stability Constants of Mixed Ligand Complexes
    Chen Yude
    1985, 6(4):  290-294. 
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    The rule of stability of mixed ligand complexes has been investigated.
    Determination of Disproportionational Dissociation Constants of μ-Oxo-BisCBis-(O-Alky Dithiocarbonato)-Oxo-Molybdenum (V)] Complexes
    Bai Mingzhang, Sun Lijuan
    1985, 6(4):  295-297. 
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    Using an improved method, compounds of type Mo2O5(S2COR)4) (R = Me,Et, n-Pr, i-Pr, n-Bu, i-Bu) were prepared. Their disproportionational dissociation constants were determined, and the visible spectra were discussed as well.
    Complexes of Crown Ether with the Rare Earth Nitrates(Ⅺ)—Studies on Solubilities of the Ternary System, Y(NO3)3·3H2O-B15C5-C2H5OH, at 18℃
    Ren Dehou, Jiang Haiying, He Mingan, Li Chenglin, Pei Hong
    1985, 6(4):  298-300. 
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    The solubilities of the ternary system, Y(NO3)3·3H2O·Bl5C5·C2H5OH, at 18℃ have been investigated by the modified semimicro phase equilibrium method. The results indicated that there are two solubility curves for this ternary system, the long one correspounds to the solid phase of the complex, Y(NO3)3·B15C5·3H2O· 1.5C2H5OH, the short one to solid phase of B15C5. The curve of refractive indices for saturated solutions consists of two branch lines, which correspound with two branch lines of solubility curve. We have not found another complex species having different ratios, Y/crown.
    Atomic Absorption Spectrophotometric Studies on Rare Earth Element (Ⅱ)—The Enhancement Effect of Double Complexing Agents on Ytterbium in an Air-Acetylene Flame
    Zhou Zhiming, Wu Dehuai, Wu Xiuqin, Liang Haiying
    1985, 6(4):  301-305. 
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    The enhancement effect of double complexing agents on ytterbium is studied.Citrate, tartrate,EDTA, urea, and 5-sulfosalicylic acid are chosen as complexing agents. When the sum of the molar concentration of two complexing agents is kept constant as their ratio is varied, three types of enhancement effect, namely competitive, additive and synergistic, are found. The mechanism of the enhancement, the distribution of ytterbium atoms in the flame and the interferences of the concomitant elements and their elimination are studied. The sensitivity is increased to 0.15ppm/1% absorption. The results show that double complexing agents are more sensitive and selective for the determination of ytterbium than single complexing agents.
    Spectrophotometric-Gomplexometric Titrations(Ⅲ)—The Titration of Micro-Quantities of Titanium (Using Benzilic Acid as Masking Agent)
    Chen Yougzhao, Qiu Ruolan, Chen Huanguang
    1985, 6(4):  306-310. 
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    Benzilic acid was found to be a specific masking agent for Ti(Ⅳ) at pH4.5-7.0. This paper reports that using the "DCTA-benzilic acid masking method", 3-100μg of Ti (in 35ml) can be accurately spectrophotometrically titrated at pH5.5 using standard zinc solution as the back titrant and xylenol orange as the indicator. The selectivity is very high. The following ions will not interfere. Th, Zr, Fe(Ⅲ), Al, Ga, In, Tl, Cr(Ⅲ), As(Ⅲ), U(Ⅵ), Mo(Ⅵ), Sc, Y, Yb, Nd, Cu, Pb, Ni, Co,Cd, Ag and the alkali earths. The TiO2 content in quartz as little,as 0.005% can be accurately determined with this method.
    Study on the Measurement of Zeolity Molecular Sieve with Trimethylsilycation of Gas Chromatograph Method
    Ma Sujie, Xu Ruren, Chen Zheng, Duan Jian, Yu Long
    1985, 6(4):  311-314. 
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    Low-molecular weight trimethylsily derivatives of silicate amons was prepared by the trimethylsilycation of various silicate and investigated completely. The good mc-thod to study silicate was obtained and used to examine the changes of the lower polysilicate anions of zeolite during its transformation. The transformation mechanism of zeolite was completely proved.
    Study on PVC Membrane Electrode (Ⅰ)—Development of a Chlorobismuthate (Ⅲ) Complex Anion- Selective Electrode
    Guo Dingli, Cheng Zhipeng, Gao Huashou
    1985, 6(4):  315-317. 
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    Anew bismuth (Ⅲ) ion-selective electrode of PVCmembrane based on the associated susbstance of quaternary ammonium salt 7402 [CH5(CnH2n+1)3N]+Cl-, n = 9-11] and bismuth chloride-complex has been prepared.The electrode exhibited a linear response to the chlorobismuthate (Ⅲ) complex anions within the concentration range 5×10-5 - 1 × 10-1M [Bi(Ⅲ)] in 2.5N HCl solution. Detection limit is 3.5× 10-5M. Their calibration plots have a slope of 40mVper activity decade. It seems to be that the response characteristics of the membrane electrode is better than that of coated wire electrode. The electrode mentioned in this brief report may be used as a new tool for analysis of bismuth (Ⅲ) ion.
    Study of PVC Membrane Tetraiodobismuthate (Ⅲ)Ion-Selective Electrode
    Qi Hongtao, Kuang Shumin, Cai Qihua
    1985, 6(4):  318-320. 
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    A PVCmembrane bismuth (Ⅲ) ion-selective electrode based on the triheptyl-dodecyl-tetraiodobismuthate (Ⅲ) ion pair is described. In a solution of 0.15 MKI, the electrode exhibits Nernstian response for bismuth (Ⅲ) ion over the concentration range from 1 × 10-2Mto 3×10-6Mwith a slope of 60 mV (at 25℃). The detection limit is down to 1.3× 10-6M. Membrane potentials are independent of pH 1-4. The potentiometric selectivity coefficient of some anions have been measured. The preparation of the electrode and optimum conditions for its use are discussed.
    Synthesis of Pyridylalkanols and Their Derivatives
    Chen Ruyu, Chen Jinlong, Wang likun, Chen Linzhi
    1985, 6(4):  321-324. 
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    Eight new 2-[α(or γ)-pyridylalkoxy] tetrahydrofurans (where n = 4, 5, 6, 10), have been prepared by the reaction of 2-(ω-chloroalkoxy)tetrahydrqfurans with picolylsodium.They were hydrolyzed, to form the corresponding pyridylalkanols, four of which have not been reported before. These compounds inhibited the growth of wheat coleoptile.
    Fast Atom Bombardment Mass Spectrometry of Bile Acids and Their Succinyl Derivatives
    Da Shilu, D. Fraisse
    1985, 6(4):  325-329. 
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    The fast atom bombardment (FAB) mass spectra of free bile acids and their succinyl derivatives are described. Using glycerol or thioglycol as "matrix compatible solvent" of the samples studied, it is noted that various matrix is different in enhanced sensitivity. In FABnegative ion mass spectra the typical (M- n)- cluster ion is observed and the (M- 1)- ion shown as its highest intensity is the base peak for each of the samples.
    Synthesis of Tertiary Alkyl Mercaptans from Tertiary Alkyl Alcohols
    Cao Zhengbai, Chen Keqian
    1985, 6(4):  330-332. 
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    Amethod of synthesis of tertiary alkyl mercaptans by the reaction of sulfuric acid and thiourea with tertiary alkyl alcohol is suggested in this paper. Six tertiary mercaptans have been prepared by this method. For the tertiary butyl mercaptan, the method of synthesis is further studied both by changing the concentration of sulfuric acid and by replacing sulfuric acid with hydrochloric acid or phosphoric acid.
    Study of Geometric Isomers of Some Vinylphosphate Insecticides (Ⅲ)—Isomerization of (Z)-to (E)-Isomer of O,O-Diethyl-O-(1-Ethoxycarbonyl-1-Propen-2-yl) Thiophosphate
    Shao Ruilian, Dong Xiyang, Zhang Chunzao, Li Jifeng
    1985, 6(4):  333-335. 
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    The isomerization of O, O-diethyl-O-(1-ethoxycarbonyl-1-propen-2-yl)thiopho-sphate (I) has been studied. The Zisomer of (I) was converted into mixtures with higher E/Zratio by treatment with p-toluenesulfonic acid, borontrifluoride and acidic ion exchange esin. The E-isomer is insecticidally more active than the corresponding Z-isomer.
    Kishner-Wolff Reaction Using Phase Transfer Catalyst for Simple Aromatic Carbonyl Compounds
    Huang Qipeng, Yu Kang, Tang Shikun, Gan Weimin, Wang Hui, Liang Bailing, Huang Wolin
    1985, 6(4):  336-338. 
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    The limitation of application of Kishner-Wolff reaction using phase transfer catalyst was studied. Eight aromatic carbonyl compounds i. e., benzophenone, fluo-renone,acetophenone, benzaldehyde, p-amino-benzaldehyde, p-methoxybenzaldehyde, o-chlorobenzaldehyde, p -nitrobenzaldehyde were investigated.
    Synthesis of Water Soluble Bis-crown Ethers
    Qin Shengying, Jiang Lijian
    1985, 6(4):  339-340. 
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    This paper discribes the synthesis of amide-type bisbenzocrown ethers bearing two carboxymethyl groups on the briged chain. That is, two N, N'-bis(4'-aceta-midobenzocrown ethers) ethylenediamine-N,N'-diacetic acid were obtained by the reaction of EDTAdianhycride with 4'-aminobenzo-12-crown-4 or 4'-aminobenzo-15-crown-5.
    Synthesis and Properties of Polysubstituted Pyrrole (Ⅰ)
    Li Bao, Zhang Shuwen
    1985, 6(4):  341-342. 
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    Acetylacetone was treated by p-chloro-ω-bromoacetophenone to give 1-(p-ch-lorophenyl)-3-acetyl-l,4-pentandiketone (1). Nine new 1-aryl-2-methyl-3-acetyl—5-(p-chlorophenyl) pyrroles (2)-(10) have been synthesized by the reaction of (1) with various primary amines. Semicarbazones (11)-(18) were prepared from (2)-(9).Compounds (1)-(18) are reported for the first time.
    Measurement of Integral Heat of Solution of La(NO3)3·6H2O in Ethanol
    Zhang Zhcnggong, Zhang Quanzhcn, Zhu Shcnghua
    1985, 6(4):  343-346. 
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    The integral heat of solution of KGl (1 class, standard grade) in water was measured by using the Popoff's isothermal jacket calorimeter. The value obtained is △H = 17523J/mol ± 0.1%. This result is in agreement with that reported by P. K. Mishenko & proves that the instrument used is reliable. By using this instrument, the integral heat of solution of La(NO3)3·6H2Oin ethanol was measured to be△H= 9.713±0.2KJ/mol.
    A Study on the Temperature-Programmed Desorption of Hydrocarbons on HZSM-5 Zeolite
    Yan Yichun, Qin Guanlin, Wu Chuanchang, Gu Liangzheng
    1985, 6(4):  347-350. 
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    The temperature-programmed desorption (TPD) of hydrocarbons on HZSM-5 zeolite has been investigated. Experimental data showed that only one main desorption peak appeared for n-hexane, cyclohexane and benzene, but for p- and m-xylene there were two desorption peaks. The order of the desorption activation energy obtained is: n-hexane >p-xylene>benzene>cyclohexane. The steam treatment of HZSM-5 at 600°C exerted little influence on TPDof n-hexane, but had a greater effect on TPD of xylene. At low adsorption amount, the molecules of xylene are mainly adsorbed on the less active sites near the entrance of pore channel of HZSM-5. Then they gradually move into the interior of pore channel and occupy the active sites with the increase of the adsorption amount.
    Studies on Activity Coefficients of Nonelectrolyte in Aqueous Salt Solutions —The Solubilities of n-Hexanoic Acid and n-Heptanoic Acid in Aqueous Solutions of Salts with Small Ions
    Li Wanjie, Xie Wenhui, Huang Ziqing
    1985, 6(4):  351-356. 
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    The solubility of n-hexanoic acid and n-heptanoic acid at 25℃ was determined respectively in water as well as in the aqueous salt solution. The activity coefficient of the undissociated part of the weak acid fu has also been calculated,When we ploted log fu vs. Cs for eight salts, the results obtained are all straight-lines.
    An Approximate Formula Without Heat Capacity for Equilibrium Constant
    Zhou Zhenhua
    1985, 6(4):  357-359. 
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    According to the Free-Energy Functions the following approximate formula without heat capacity for equilibrium constant is suggested:lgKp= - (△H2980/4.576T)+ (△S2980/4.576)+a(T-298) where a = constant, obtained by use of only a single measurement of Kp.More than110 equilibrium constants of reactions have been calculated at different temperatures and the results obtained coincide very well with the experimental values.
    The Nephelauxetic Model
    Cben Zhongllou
    1985, 6(4):  360-362. 
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    In this paper the d radial function in ligand field has been expressed by adding the free-state d radial function with a empirical function. By using this model several crystalline electronic spectra of Cu2+ in environments of Cl- have been calculated and the results obtained are in good agreement with the experimental data.
    A New Method of Choosing Boundary Condition on Cluster for Covalent Solid State Simulations
    Guan Daren, Han Yingjian, Deng Conghao
    1985, 6(4):  363-365. 
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    Anew method is proposed for determining boundary condition on model for covalentsolid state cluster simulations, based on the relaxation of the boundary atoms ofthe cluster. Calculations for this model by CNDO/2 method for an adsorption problemof water on the surface of silica gel, yields satisfactory results compared with thedata of the other.
    The Influence of Poly(Bis-A)Sulfone on Crystallization of Poly (Hydroq uinone)Sulfone
    Deng Zhuo, Liu Zhiguo, Li Yinghua, Ding Youjun
    1985, 6(4):  366-370. 
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    The decreasing in crystallinity of poly(hydroquinone)sulfone (H) by incorporations of poly(bis-A)-sulfone (B) blocks into the polymer chains was observaled by X-ray diffraction. The copolymers with B/Hmore than 0.48 (moiar ratio) were found uncrystallizable. The mixing heats of these copolymers with several probe-molecules, Tg's and Tm's obtained from IGCand DSCindicate that the two components are compatible.
    Vinyl Polymerization with Titanocenes(Ⅳ)—Studies on the Copolymerization of Acrylonitrile and Methyl Methacrylate in the Presence of Titanocene Dichloride
    Ye Dakeng, Li Guihua, Liu Dehai, Liu Daoyu
    1985, 6(4):  371-375. 
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    The influence of irradiation of light on the copolymerization of acrylonitrile (M1) and methyl methacrylate (M2) in the presence of titanocene dichloride was investigated.Irradiation of light is a prerequisite for this process. Mole fractions of M1 and M2 units in the copolymers were determined by the 1H NMRspectra. The monomer reactivity ratios were evaluated by four methods. According to experimental results, a free radical mechanism was proposed further.
    Studies on the Amino Acids and Peptides in Ginseng
    Zhang Jin, Zhao Zhongjian
    1985, 6(4):  376-377. 
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    In this paper, the amino acids and acidic peptides were determined in different site, and two acidic peptides were isolated from the flower in Klin Ginseng.
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