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    24 December 1982, Volume 3 Issue 4
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    Articles
    THE MECHANISM OF FORMATION AND CRYSTAL GROWTH OF MOLECULAR-SIEVE-ZEOLITE (Ⅲ)—— THE EFFECT OF FAUJASITE "DIRECTING-AGENT" AND ITS KINETICS
    Xu Ruren(Hsu Rhu-Reng), Zhang Jianmin
    1982, 3(4):  437-442. 
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    In this paper, two empirical equations, I = 6 (T +100) t100.0035T and I = 398.15(t2 - 0.8)-0.06lg11T, were suggested to express the correlation between the intensity ( I ) of Na23-NMR spectrum, which is proportional to the number of Na+ in crystal lattice of Xtype zeolite, aging time (t1) and the time (t2) of complete crystallization of "directing-agent" at different temperature. On the basis of these results, a kinetic model of crystal growth of NaY type zeolite in presence of so-called directing-agent was suggested, and the mechanism of the "directing-agent" effect has been characterized.
    A STUDY ON THE PHASE DIAGRAM OF BINARY SALTS SYSTEM KNO3-KCl
    Zhang Qiyun, Li Wenhua
    1982, 3(4):  443-446. 
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    Astudy has been made of binary salts'system KNO3-KCl by the methods of DTA, visual polythermal and X-ray powder diffraction. An incongruently melting compound KNO3·KCl which decomposes at 359℃ andtransittes at 124℃ and 271℃ has been found in the system. Peritectic point of this compound lies in the composition containing 12.5wt% KCl. The values of the eutectic between KNO3 and KNO3·KCl are 318℃ and 5.0wt% KCl. Another metastable compound 4KNO3 KCl incongruently melting at 342℃ may also existes in this system. From the results of DTAand X-ray diffraction, no evidence was found for solid solution on the both sides of KNO3 and KCl.
    A STUDY ON TERNARY SYSTEM LaCl3-THIOUREA-H2O AT 30℃ AND AT 50℃
    Tang Zongxun, Guo Zhizhen, Chen Peihang, Ma Jinhua, Chen Yunsheng
    1982, 3(4):  447-451. 
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    By using the heptahydrate and trihydrate of lathanum trichloride as starting materials, the solubilities and the refractive indices of the saturated solutions in the ternary system LaCl3-CS(NH2)2-H2O have been investigated. The isotherms of solubilities and refractive indices of the system at both 30℃ and 50℃ consist of 2 branches, one corresponding to the saturated solution of LaCl3·7H2O and the other to CS(NH3)2. The solubility data obtained are: LaCl3 - 49.32% and CS(NH2)3 -16.83% at 30℃ and 51.72% and 32.46% at 50° in pure water, respectively. The compositions of the double saturated solutions are: LaCl3 - 46.72%, CS(NH2)2-6.15% at 30℃ and 48.05% and 8.98% at 50℃, respectively.The presence of solid phase, hexahydrated LaCl3 reported by Z. M. Zholalieva et al, in 1978 was not found.
    GRAN TITRATION WITH INCREMENT METHOD——DETERMINATION OF TRACE CHLORIDE
    Yang Shuxun, Sun Bingyao
    1982, 3(4):  452-458. 
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    This paper discusses the influence of the precipitate solubility on Gran titration. An equation of the error has been derived from the modified Gran function. The theoretical errors have been calculated for determining chloride of various concentrations. If the titrant (AgNO3) concentration is 2× 10-3 M, the determination is suitable in the range of 5×10-6 M—5 ×105-M.In order to improve the sensitivity and accuracy,increment method is suggested for determining the chloride below 5×10-6M. The limit concentration of chloride for determining is 1×10-6 M and the coefficient of variation is 20%.
    THE ENHANCING EFFECT OF LIGANDS ON ATOMIC ABSORBANCE OF Cu FOR FLAME AAS ANALYSIS
    Zhou Zhirui, Wang Kaixiong
    1982, 3(4):  459-465. 
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    In the present paper, an appreciable enhancement and its mechanism of some ligands on the atomic absorbance of Cu by aspirating directly the solution into a flame atomic spectrophotometer have been studied.In the presence of the chelating agents,Cu shows an obvious enhancing effect on the atomic absorption, but Zn, Cd, Fe without showing any effect. The difference of the enhancing effect is explained with the bond dissociation energy and the electronic configuration for the ground level of atom.An addition of few micromoles of the corresponding chelating agent to the series of the standard solution, the enhancing effect on the atomic absorbance of Cu for the flame atomic absorption spectroscopic analysis is repaired.
    INVESTIGATIONS ON POLAROGRAPHY WITH LINEARLY CHANGE POTENTIAL (Ⅲ)——THE THEORY OF ADSORPTION CATALYTIC CURRENTS
    Chang Tsow-Shein
    1982, 3(4):  466-474. 
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    In this paper the equation of adsorption catalytic currents in linearly change potential polarography is described.
    ELECTROANALYTICAL CHEMICAL STUDIES OF RARE EARTH ELEMENTS ( Ⅵ )——POLAROGRAPHIC STUDIES OF SAMARIUM-RHODAMINE B-AMMONIUM CHLORIDE SYSTEM
    Ye Xianzeng, Gao Xiaoxia(Kao Sheau-shya)
    1982, 3(4):  475-481. 
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    The polarographic behavior of rare earths with rhodamine Bin ammonium chloride solution has been further studied with Sm3+ as an another example. (1) In the presence of a small amount of diphenylguanidine, the addition of Sm3+ decreases the height of the adsorptive single-sweep derivative wave( -1.45V, SCE) as in the case of Y3 + does[1] There is a linear relationship between the concentration of 3×10-7-2×10-6M Sm3+ and the decreases of wave heights. (2) In the ammonium chloride solution with 10% dioxane, the complex of Sm3+ -rhodamine Bexhibits a reductive dc pola-rogram at -1.70V (SCE). The wave height is directly proportional to the concentration of Sm3+ within the range of 2×10-6-2×10-5M. Since the adsorptive wave of rhodamine Bprecedes the complex wave, it is hard to further increase the sensitivity either by dc or single-sweep polarography. Acomparison of RE-rhodamine Bcomplexes in dioxane was made in which Eu is more sensitive than Sm and Er is the most sensitive one among them.
    RING CLEAVAGE REACTION BETWEEN ALKYL(ARYL) ACETOXYSILANES AND EPOXIDES
    Xie Qinglan, Wang Suhua, Wang Jitao
    1982, 3(4):  482-488. 
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    Ring cleavage reaction between alkyl (aryl) acetoxysilanes and epoxides using 5-tert-butyl-2-furanatochromium (III) and aluminium chloride as catalysts was studied and the corresponding products substituded siloxy-propyl acetate were obtained. Experimental results show that it is more advantageous in the two experimental routes to make use of 5-tert-butyl-2-furanatochromium (III) than alumium chloride.
    THIN-LAYER CHROMATOGRAPHY OF BIS-(CYCLOPENTADIENYL)-DI-(ARYLOXY)-TITANIUM, ZIRCONIUM AND HAFNIUM DERIVATIVES
    Xie Zhenzhen, Chen Shoushan
    1982, 3(4):  489-494. 
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    Thirty-two derivatives of bis-(cyclopentadienyl)-di-(aryloxy)-titanium, zirconium and hafnium have been separated by thin-layer chromatograghy (TLC) using silica gel as absorbent and toluene-acetone(30: 1) or toluene-p-dioxane(30:1) as developer. According to the Rf values of the compounds as well as (3 values of their cyclopentadienyl ring protons, their separating rules In thin-layer chromatography were discussed.
    ACIDOLYSIS REACTIONS OF BIS(CYCLOPEN-TADIENYL)-DI-(ARYLOXY)-TITANIUM
    Liu Yiyin, Chen Shoushan
    1982, 3(4):  495-501. 
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    Acidolysis reactions of bis-(cyclopentadienyl)-di-(aryloxy)-titanium were studied. It was proved that acidolysis reactions go step by step. According to the reaction conditions, the second-step acidolysis product, bis-(cyclopentadienyl)-titanium dihalides, and the first-step acidolysis product, bis-(cyclopentadienyl)-(aryloxy)-titanium halides, were obtained. Reaction conditions were discussed.Through above-mentioned reactions, a series of new bis-(cyclopentadi nyl)-(aryloxy)-titanium halides have been synthesized with good yields.Starting from bis-(cyclopentadienyl)-(aryloxy)-titanium halides, a few new derivatives with formulae Cp2Ti(OAr)Ar and Cp2Ti(OAr)(OAr') have prepared.
    APPLICATION OF POLYMER THEORY TO BINARY ALUMINATE AND BORATE SYSTEMS
    Dou Shixue
    1982, 3(4):  502-508. 
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    The thermodynamics of basic oxide-aluminate and borate systems are approached in terms of statistical polymer theory. Alinear chain model is presented for binary aluminate systems, in which the ion AlO33- and BO33- are treated as the monomeric unit. The activities of the constituents can be expressed as functions of the Al2O3 and B2O3 content under the assumption that the systems exhibit Temkin behavior and do not produce ring anions. The activities predicted for several systems are in agreement with experimental values. Quantitative expression of free energy of mixing is derived. Gel point is related to the limitation of application of polymer theory to the melts.
    APPLICATION OF MOLECULAR ORBITAL METHOD TO DYE CHEMISTRY (V)——Computation of the Absorption Spectrum of Anthraquinone Derivatives by P.P.P.-SCF-CI Method
    Li Zhongshi, Cheng Lubo
    1982, 3(4):  509-515. 
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    In order to study the relationships between color and constitution of anthraquinone dyes, a calculated model of hydroxy derivative of anthraqui-none is designed. The bond orders, electron densities and transition energies of 9 dyes were computed by means of the Pariser-Parr-Pople-SCF-Configuration Interaction method. The good result agreement with the experiment values is observed and well discussed.
    Xα Calculation on MnO4- and CH4
    Yu Weizhou, Liu Yongzhen, Zhang Mignyu, Feng Guochen, Jiang Yuansheng
    1982, 3(4):  516-520. 
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    The SCF-SW-Xα method used for polyatomic molecules is programmed via a TQ-16 computer. The calculation has been done for molecules MnO4-and CH4 and the results are presented. In comparison with the same kind of calculationfon MnO4- given by Johnson, all of them are approximate except a pair of adjacent levels, i. e. 6a1 and 6t2, are reversed in magnitude. Thus, it seems worthwhile to compare them with the results of ab initio calculation, and some preliminary analysis has been made to interpret this discrepancy. Also, a part of results are compared with experimental data.
    INVESTIGATION OF HYDROGEN BOND FORMATION BETWEEN ISONITRILES AND HYDROXYL COMPOUNDS BY SCF MO METHODS
    Zheng Shijun, Fu Xiaoyuan
    1982, 3(4):  521-526. 
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    By means of CNDO/2 and ab initio(STO - 2G) methods, we have calcula-ted the energies of systems R-N ≡ C…H-O-R'. The results of calculation confirm the formation of rather strong hydrogen bonds between isonitriles and hydroxyl compounds, as indicated by experimental evidences. The calculated hydrogen bond energies vary with the same tend as the red shift of IRspectra of the OHbonds. The relative stability of the Hbond formed by isonitrile and nitrile is also discussed.
    THE STUDIES OF SEMICONDUCTIVITY OF CATION EXCHANGE RESIN OF FUROIC ACID
    Zhou Chaohua, Wu Jingjia
    1982, 3(4):  527-532. 
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    The chemical structure of cation exchange resin of furoic acid was discussed on the infrared absorption spectra and ESR. The structure is regarded as a conjugating unsaturated C=Clinkage formed by the acidic cleavage of furan ring of furoic acaid nd condensation reaction of the cleavage compounds under certain conditions. Unpaired electrons of appreciable concentration have been found in the resin of furoic acid by means of ESRspectroscopy. The g factor of the spectra of resin of furoic acid was 2.0088. Hence, the electrons in resin would be expected to be unlocalized electrons which are stabilized via resonance in high conjugation. Therefore, the resin is semiconductive. According to the resistance-temperature characteristic of resin measured at various temperature, the resin is found to be an intrinsic semiconductor.The photoconductivity of the resin was measured under visible light and ultraviolet light at various voltage.
    THE TORSIONAL BRAID ANALYSIS OF VINYLCHLORIDE-VINYLACETATE-VINYLALCOHOL TERPOLYMER AND ITS CROSSLINKED SYSTEM WITH 4.4-DIPHENYLMETHANE DIISOCYANATE
    Ma Dezhu, Zhu Qingren, Zhou Yinfang, Chen Shunxi, Luo Xiaoli, Hou Jianguo
    1982, 3(4):  533-539. 
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    The thermo-mechanical spectra for vinylchloride-vinylacetate(VC-VAc) copolymer and four vinylchloride-vinylacetate-yinylalcohol (VC-VAc-VA) terpolymer, in which-the molecular weight is similar, but the VAcontent is different, were determined by torsional braid analysis. At the same time, we also measured the thermo-mechanical spectra for several crosslin-ked systems composed of four terpolymer (VC-VAc-VA) and 4, 4'-diphe-nylmethane diisocyanate with stoichiometric and non-stoichiometric amounts of hydroxyl and isocyanate group. The hydrolysis of (VC-VAc) copolymer, which led to occuring of the hydroxyl group, has -definite effect on the glass transition temperature, but the effect of crosslinking on the glass transition temperature is more strong.For the crosslinked system with stoichiometric amounts of hydroxyl and isocyanate group the crosslinked density presented the linear relation with the glass transition temperature, however for the crosslinked system with non-stoichiometric amounts, the relation between the crosslinked density and the glass transition temperature was more complex.
    BIOMEDICAL APPLICATIONS OF IMMOBILIZEDENZYMES ( I )——PREPARATION OF IMMOBILIZED UREASE BY POLY-ACRYLAMIDE-ENTRAPMENT AND ITS PROPERTIES
    He Binglin(Ho Ping-lum), Chen Changzhi, Tong Mingyong, Zong Jianchao, Pan Jilun
    1982, 3(4):  540-546. 
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    Matrix-entrapment is one of the major methods of enzyme-immobilization. In order to overcome its shortcomings, such as low amount of entrapment, low reactivity because of high polymer content and low diffusion, as well as irregular shaping, the entrapment of urease by crosslinked polyac-rylamide had been investigated and spherical immobilized urease had been prepared with following properities. High amount of immobilized enzyme (1 part of enzyme to 1 part of polymer) and about 50% relative activity of the immobilized urease. Reactivity towards urea hydrolysis was 120mg/ ml for two hours at 37℃. The stability of the immobilized urease was increased in comparison to the free urease. When stored at 4℃, the loss of initial activity was 8% after 66 days, 22% after 106 days and at 37℃ the loss was 18% after 11 days. The spherical shape of the beads improved the mechanical strength and enhanced the column velocity. No leakage of the immobilized urease could be detected. The above properties render the immobilized urease suitable for active material as artificial kidney.
    STUDY ON MECHANISM OF HIGHLY EFFECTIVE MAGNESIUM-CONTAINING CATALYST FOR ETHYLENE POLYMERIZATION
    Bu Naiyu, Xie Youchang, Bai Chunli, Sun Maofen, Tang Youqi
    1982, 3(4):  547-554. 
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    A typical highly effective magnesium-containing catalyst prepared by chemical reactions was studied. Each reaction step in the preparation was examined by X-ray powder diffraction, IRand chemical analysis.In the first step, C2H6OHreacts with MgCl2 in gasoline, the lattice of MgCl2 crystal is broken and a solid adduct, MgCl3·nC2H5OH (n≤6), is formed. In the second step, by adding Al(iso-C4H9)3, MgCl3 · nC3H6OHdisappears and a complex solid product containing Mg+2, Al+3, Cl- and OC2H5- is formed. Finally TiCl4 is added, a powder product as the main component of a highly effective catalyst for ethylene polymerzation is obtained. In this last step, most of Al+3 and OC2H5- in the solid product from the second step dissolves in the liquid medium, thus Mg+3 and Cl- ions recombine to form MgCl2 crystallites as a supporter, which can be identified by X-ray diffraction. The compound of titanium, the active ingredient of the catalyst, is highly dispersed on the surface of MgCl2 crystallites and thus a highly active catalyst is obtained which contains plenty of interstices between the crystallites, and the transfer rate of ethylene during polymerization is enhanced. Hence the activity is higher than the activity of those produced by the milling method.MgCl2 crystallites are found in some other Mg-containing catalysts prepared by chemical reactions with different materials, so that they should have a similar mechanism of high activity.
    SYNTHESIS AND PROPERTY STUDY OF A MODEL COMPOUND OF ACTIVE CENTER OF NITROGENASE
    Liu Xisheng, Xu Jiqing, Li Jing, Niu Shuyun, Li Shuqin, Sun Cunting, Chen Yonyi, Lin Yongqi, Yang Shichen, Zhao Ying
    1982, 3(4):  555-561. 
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    In this paper, we report the synthesis, spectra properties, catalytic activity and reconstitution properties of a model compound of active center of nitrogenase, which displays good reconstitution behaviour with inactive FeMo protein from azotobacter vinelandii mutant strain UW45. The turnover of acetylene reduction with present compound as catalyst and KBH4 as reductant is 11.11nM products/nMMo·min. Selectivity to ethylene is 74.8%.15N labeled experiment shows that it displays appreciable activity to reduce 15N2 to 15NH3. The activity of acetylene reduction upon reconstitution of this compound with inactive FeMo protein and addition of Fe protein is high as 38.1 nMC2 H4/nMMo·min., equaling to 9% of that of nitrogenase. The electrophoretic mobility after reconstitution of inactive FeMo protein with the model compound is closer to that of normal FeMo protein than reconstitution before.
    ISOLATION OF THE COFACTOR-DEFICIENT MoFe-PROTEIN FROM A VINELANDII MUTANT STRAIN UW-45 AND THE STUDY OF ITS PROPERTIES
    Cui Tiejun, Zhou Hui, Lin Yongqi, Yang Shichen, Tao Weisun
    1982, 3(4):  562-566. 
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    With the aid of cellulose chromatography and preparative electrophore-sis, a purified cofactor-deficient MoFe-protein has been obtained from A. V.mutant strain uw-45 with a yield of 18.4%.After reconstitution of the cofactor-deficient MoFe-protein with the FeMoco,a new active protein was formed with a molecular weight of 220,000.The active protein could reduces CH = CHto CH3=CH2 having a specific activity of 5.85nM/min · mg protein as much as 22.7 times of the extracts of A.V.mutant strain uw-45. Similar to the MoFe-protein,the migration of the active protein during the course of electrophoresis was found to be slower than that of the cofactor-deficient MoFe-protein. Elemental analysis showed that the iron content was twice as much as that of the cofactor-deficient MoFe-protein. The visible absorption spectrum of the active protein was found to be identical with that of MoFe-protein. On the basis of the above results we postulate that the cofactor-deficient MoFe-protein can be transformed into MoFe-protein by combining with the FeMoco.
    ON THE MECHANISM OF HYDROGEN EVOLUTION FROM AQUEOUS SUSPENSION OF FERROUS HYDROXIDE
    Zhang Jingkung, Xianyu Yuqiong, Ni Yinhai
    1982, 3(4):  567-569. 
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    The chemisorption of hydrogen ions on suspensions of Fe(OH)2 causes the evolution of molecular hydrogen. The coprecipitation of Ni(OH)2 improves the yield because nickle ions stabilize the hexagonal lattice of Fe(OH)2. Mossbauer spectroscopy indicates that Ni is present also in that lattice. Glucose improves further the yield because hydrogen ions chemisor-bed on Fe(OH)2 and Ni(OH)2 may act as catalyst to shift the equilibrium of mutarotation. The regenerated hydrogen ions in solution account for the additional hydrogen evolution.
    STABILIZATION OF TETRAVALENT LANTHANIDE IN AQUEOUS SOLUTION (Ⅰ)——STABILIZATION OF TERBIUM(Ⅳ) IN AQUEOUS HEXAMATEPHOSPHATE SOLUTION
    Yang Rudong, Sun Xiaofei
    1982, 3(4):  570-572. 
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    The stabilization of terbium(IV) with hexametaphosphate in aqueous solution has been studied in the paper. Astable solution of terbium( IV ) with red brown color was obtained, by dissolving the hydrated oxide of terbi-um(IV) in sodium hexametaphosphate solution. This solution has a broad band absorption near 375nm, which is considered to be, one of characteristics of terbium(IV) compounds. The color of the solution of terbium(IV) will remain unchanged for a long time at 6<pH<13. The red brown solution of terbium(IV) possesses some colloid properties, i. e. Tyndal effect, electrophoresis and flocculation by adding a small amount of electrolyte. It is confirmed by chemical analysis that the flocculation product is Tb(IV) hydrated oxide. Thus it can be seen that the stabilization of Tb(IV) in aqueous solution is due to the formation of colloid solution.
    STABILIZATION OF TETRAVALENT TERBIUM WITH ORTHOTELLURATE ANION IN AQUEOUS SOLUTION
    Hua Suming, Yang Rudong
    1982, 3(4):  573-576. 
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    Tetravalent terbium is not stable in aqueous solution because of the high potential of Tb(IV)/Tb(III)couple, The authors of this paper have obtained the Tb(IV)in aqueous solution of orthotellurate anion. The UVand visible absorption speactra of this solution have showed the existence of Tb(IV) complex, and its absorption band with the highest absorption at 360nm has been observed. The effects of various factors upon the formation and the stabilzation of Tb(IV) have been studied. Ablack-red solid containing Tb(IV) has been seperated from the solution, whose constitution is to be investigated.
    THE CRYSTALLIZATION FIELD AND DIRECTING AGENT OF BORON-SILICON PENTASIL TYPE ZEOLITE
    Pang Wenqin, Jing Xiaoyan, Zhang Milin
    1982, 3(4):  577-579. 
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    Isothermal phase transformation diagram was developed for TPA2O-B2O3 -SiO2-H2O system at 160#. B-Si pentasil type zeolite was obtained as a pure phase from the reaction mixture with the mole ratio SiO2/B2O3 being 55-80, and we have for the first time prepared the directing agent of this kind of zeolite. It was proved by electron diffraction technique that the colloidal particles of directing agent with the structure of corresponding zeolite framework, which acts as nuclei, dispersed highly and exhibit directing effect powerfully for the crystallization of B-Si pentasi type zeolite. Also some properties of B-Si pentasil type zeolite such as structure of framework, stability to heat and acid, selective absorption to the infrared and adsorption properties have been studied, May be it provides the evidence for opening up the application of this zeolite.
    A NEW METHOD FOR THE SYNTHESIS OF HYDROGEN STORAGE COMPOUNDS——REPLACEMENT-DIFFUSION METHOD FOR Mg2Cu
    Shen Panwen, Zhang Yunshi, Yuan Huatang, Chen Shengchang
    1982, 3(4):  580-582. 
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    A new method for the synthesis of Mg2Cu is presented. The main feature of the method is using a suitable nonaqueous solution of cupric salt, such as CuCl2 in predried methylcyanide, to react with magnesium filings in an atmosphere of argon. The replaced copper is deposited on the surface of Mg. After heating the alloy at 500-580℃ under an atmosphere of argon for homogeneity, Mg2Cu is obtained as a dark grey powder. The properties of this chemically synthetic intermetallic compound are essentially inden-tical with those reported in the literature.
    SYSTEMATIC CHECK OF SYMMETRY GROUP TABLES
    Jin Zhongsheng, Jin Songchun, Liu Yongsheng, Guo Dongyao
    1982, 3(4):  583-585. 
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    Using the theorems of structure factor type[1,2], we have systematically checked systematic extinction conditions, the conditions of special type phase (0-π, ±π/2, ±π/4 and ±π/4) and general type phase in International Tables for X-Ray Cryst. Vol.1[3], The results for 15 s.g. are given the above table. The rest (215 space groups) are all right.
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