Loading...
CJCU

Table of Content

    24 February 1987, Volume 8 Issue 2
    Previous Issue    Next Issue
    Articles
    Studies of the Shape-Selective Catalysis of ZSM-5 Zeolites Modified with Alkali Compounds
    Zeng Zhaohuai, Zheng Chaowen
    1987, 8(2):  97-102. 
    Asbtract ( )   PDF (528KB) ( )  
    Related Articles | Metrics
    Toluene was alkylated with methanol to produce xyienes rich in the para iso-mcr over ZSM-5 zeolites modified with alkali compounds by ion-exchang, impregnation, and mechanical mixing. At reaction conditions, the conversion of toluene and para isomer in the xylene product were 33.9% and 79.4% respectively using the zeolite catalyst which was modified by sodium cation exchang followed by rapid impregnation with sodium acetate. The selectivity of p-xylene was also enhanced by poisoning the catalysts with nitrogenous bases. It was observed that the higher the p-xylene selectivity in toluene alkylation with methanol, the lower the catalytic activity in xylene isomerization over the same catalysts. The results of studies on surface properties by TPD, pyridine pulse poisoning, and BETweight methods indicated that the total acidity was decreased, the acid strength was weakened, and the relative sorption capacity of p-xylene vs. m-xylene was enhanced after modifying with alkali compounds.
    Studies on Silicic Acid and Its Salts (ⅩⅨ)--The Study of Acid Strength of Mono-, Di-, and Tri-Silicic Acids by CNDO/2 Method
    Wang Guoxiong, Mao Yan, Chen Rongsan, Dai Anbang
    1987, 8(2):  103-108. 
    Asbtract ( )   PDF (484KB) ( )  
    Related Articles | Metrics
    The strength of O-Hbond in silicic acid from monomer to trimer has been investigated by using CNDO/2 method. The computed values give a reasonable explanation for the experimentally measured acid strength which is found to be.monomer >dimer<trimer.
    Studies on Sodium Silicate Solutions and Sodium Aluminosilicate Solutions
    Ma Shujie, Xin Minqian, Feng Dianying, Ding Hong
    1987, 8(2):  109-111. 
    Asbtract ( )   PDF (207KB) ( )  
    Related Articles | Metrics
    The method of trimethylsilylation-gas chromatography was used to study anion distribution in sodium silicate solutions with the ratio of SiO2:Na2O= 3.44 and different concentrations. Technique of 27AlNMR spectrum was used to identify some anions in sodium aluminosilicate solutions and study this changing regulation.
    The Extraction of Rare Earths by 1-Phenyl-3-Methyl-4-Capronyl-Pyrazolone[5] (HPMCP)--Studies on the Extraction Mechanism of La, Nd, Gd, Lu, Y and the Constitution and Behaviour of Their Solid Complexes
    Chen Youmin, Hu Zhaosheng, Jia Xiping
    1987, 8(2):  112-114. 
    Asbtract ( )   PDF (262KB) ( )  
    Related Articles | Metrics
    The extraction behavior of rare earths with HPMCP-petroleum ether has been studied. Experimental results showed that rare earth ions as Ln(PMGP)3·HPMCP form were extracted into organic phase. Their extractive constants 1gKwere calculated by the slop method. On the basis of this, their solid complexes were produced. The constitution of solid complexes is Ln(PMCP)3·2H2O. Their spectrum, IRand NMR were also studied.
    The Influence of the Copper and Zinc Matrix on the Background in the Furnace Atomic Absorption Spectroscopy
    Mo Shengjun, Wu Yuhuai
    1987, 8(2):  115-118. 
    Asbtract ( )   PDF (319KB) ( )  
    Related Articles | Metrics
    In this paper, the influence of copper and zinc chlorides and their nitrates on the background in the furnace atomic absorption spcctroseopy are discussed. The characteristics of the time and wavelength of the background were studied. The results showed the wavelength character of the background of copper and zinc chlorides is more obviouse than their nitrates, the time distribution of She nitrate background is more extensive. Under the same conditions, the background of copper and zinc chlorides is much higher than their nitrates.
    Extraction of Trace U(Ⅵ) with PMBP-Loaded Polyurethane Foam
    Wang Mingsheng
    1987, 8(2):  119-121. 
    Asbtract ( )   PDF (253KB) ( )  
    Related Articles | Metrics
    A study on extrection cf trace U(Ⅵ) with PMIP-loaded pclyurethane foam from water is described. The effect cf equilibrium time, concentration of acetic acid, cortent of U(Ⅵ), temperature and foreign ions is examined. Uranyl acetate can be quantitatively extracted by PMBP-loadod foam from 0.05.Macetic acid solution. Dis over 4.65×104and enrichment factor is over 4500. Anew procedure for preconcentration of trace U(Ⅵ) from large volume of water has been developed. Aprocedure for the PMBP foam extraction-arsenazo Ⅲ spectrophoto-metric determination of U(Ⅵ) at ppb level is cstablished.
    A New Chelate-Forming Resin Bearing 1-(2-Pyridylazo)-2-Naphthol-Sulfonic Acid (PAN-S)
    Zhou Zhirui, Liang Zhongwen
    1987, 8(2):  122-124. 
    Asbtract ( )   PDF (199KB) ( )  
    Related Articles | Metrics
    Anew chelate-forming resin bearing l-(2-pyridylazo)-2-naphthol-sulfonic acid (PAN-S) and some characteristics of this resin were studied.
    Electrochemical Studies on Precious Metal Elements (Ⅶ)--CCx Enrichment and Separation-Determination of Gold
    Zhang Yuxiang, Lu Fan
    1987, 8(2):  125-127. 
    Asbtract ( )   PDF (231KB) ( )  
    Related Articles | Metrics
    The conditions of the determination of gold were studied on glass carbon electrode by the anodic stripping voltammetry(ASV).The experiments showed that in the optimum electrolytic system of 0.lM HCl-1.4×10-6M HgCl2, there was a stable stripping peak for Au at about + 0.8V (vs. S.C.E). Its determination limit reached 5 ppb. By adopting of cotton cellulose xanthate (CCX) for entichment, the separation of Au achieved good results.This method was used for some practical sample analyses with good results. The coefficient variation was 0.73% and 2.53% respectively when two gold samples were repeatedly determined for 7 times.
    Toxicity-Structure Relationship of O-Ethyl O-Aryl N-Isopropyl Thionophosphoramidates
    Jiao Jian, Mao Zhixiang, Chen Qiqi, Xu Zongfan
    1987, 8(2):  128-132. 
    Asbtract ( )   PDF (354KB) ( )  
    Related Articles | Metrics
    Quantitative toxicity-structure relationship of O-ethyl O-aryl N-isopropyl thionophosphor-amidates was studied by the determination of their hydrophobia, electronic and hydrolytic parameters as well as their acute toxicilies towards rats. From our experimental results it seems possible that the action between organo-phosphorous toxin and receptors may include dipole interaction. According to the QSAR of our experiment, the compound with low acute toxicity may be obtained when the molecular dipole moment is small and hydrophilicity is high.
    Studies on Nitrile Oxide (Ⅱ)--A Novel Synthesis of Sinomin
    Wang Xu, Cheng Tiemin, Zhang Yizhi, Jia Qi, Cai Mengshen
    1987, 8(2):  133-136. 
    Asbtract ( )   PDF (313KB) ( )  
    Related Articles | Metrics
    A novel synthesis of Sinomin by the 1,3-dipolar addition of nitrile oxide was reported. The 1,2,3-trichlorobutylaldehyde oxime (Ⅰα) was converted into 1,2-dichloropropylnitrile oxide (Ⅱα) on action of sodium methoxide. (Ⅱα) was treated with p-acetaminobenzenesulfamide, then the addition product was converted to 3-(p-acetaminobenzenesulfanilylamide-5-methylisoxazole(ASMZ) (Ⅲα) through cycli-zation and elimination in situ. The 3-(p-aminobenzenesulfanilylamido)-5-methyl-isoxazole(SMZ) (Ⅳα) was obtained when ASMZ was heated to 120℃ in 20% sodium hydroxide solution for 2 hr.In the same way the 3-(p-aminobenzenesulfanilylamido)-5-phenylisoxazolc (SPZ) (Ⅳb) was prepared.
    Research on 2,5-Diaryl Oxadiazoles
    Pan Jiaxing, Zhang Suipo, Gao Zhenheng
    1987, 8(2):  137-140. 
    Asbtract ( )   PDF (307KB) ( )  
    Related Articles | Metrics
    Nineteen of 2,5-diaryl oxadiazoles were synthesized.Among them,eleven are new compounds. The m. p.,λmaxof UV spectra and FLspectra as will as the fluorescence quantum yields of these compounds are listed in tables.
    Studies on the Chemical Constituents of the Chloranthvs Holostegius (Hand-Mazz. ) Pei et. Shan.
    Gao Chengwei, Chen Yushu, Xie Jiamin, Zhao Shunian
    1987, 8(2):  141-142. 
    Asbtract ( )   PDF (247KB) ( )  
    Related Articles | Metrics
    Five crystalline substances have been obtained for the first time from the root of the chloranthus holostegius (Hand-Mazz. ) Pei et. Shan, growing in Yuayang County of Yunnan Province. According to their spectroscopic analyses (UV,IR, MS, 1H and 13CNMR) and physico-chemical constants, they have been identified as: β-Sitosterol(Ⅰ), β-Sitosteryl-β-D-glucoside(Ⅱ), Palmitic acid(Ⅲ), Fraxidin-8-O-β-D-glucoside(Ⅳ) and Chloranthalactone C(Ⅴ), respectively.
    The Synthesis of 1,4,8,12-Tetramethyl-1,4,8,12-Tetraazacyclopentadecane Copper(Ⅱ) Perchlorate
    Huang Ningxing, Xia Jinmou
    1987, 8(2):  143-144. 
    Asbtract ( )   PDF (159KB) ( )  
    Related Articles | Metrics
    The synthesis of the new 15-membered macrocyclic, 1,4,8,12-tetramethyl-1, 4,8,12-tetraazacyclopentadecane and its coordination with copper (Ⅱ) are reported. The IR, UVand MS of the copper complex were measured.
    The Mass Spectra of Hydroxymethyl Substituted Coumarin Compounds
    Zhao Taonan, Jiang Yianhao, Rong Lushan, Yang Jihong, Hu Yuefei, Hu Hongwen
    1987, 8(2):  145-148. 
    Asbtract ( )   PDF (299KB) ( )  
    Related Articles | Metrics
    The hydroxymethyl substituted coumarin comounds are the homonuclear compounds of Armillarisin A. Since Armillarisin Ahas a cure effect on acute bile duct cholangitis, it is of value to medicine and chemistry area. Now, not only the Armillarisin Ahas been synthesized, but also a great deal of research work attemptting to improve the cure effect by changing substituted group of the compounds has been done.We worked for finding mass spectral fragmentation rule of these compounds, which were synthesized by Department of Chemistry of Nanjing University. The results are shown in the table. The mechanism of the fragmentation of hydroxy-metyl substituted coumarin is discussed in the paper too.
    Studies on Chemical Constituent of Anemone Altaica C,A. May(Ⅱ)
    Ju Yong, Jia Zhongjian, Zhu Ziqing(Chu Tse-Tsing)
    1987, 8(2):  149-150. 
    Asbtract ( )   PDF (150KB) ( )  
    Related Articles | Metrics
    A new dispiro-lactone compound, C10H12O6, m.p. 224-226℃, was isolated from the ethyl acetate extract of the roots of Anemone altaica C.A. May, Chinese medicinal herb, by using Si gel column chromatography. Its structure has been determined as:(5R,8R)1,6,9,13-tetraoxadispiro [4,2,4,2] tetradecane-2, 10-dione by means of IR, NMR, MS spectra and X-ray diffraction analysis.
    Aggregation of Ion Pairs (Ⅱ)--Different Anion Affect on the Aggregation
    Liu Xiyu, Wang Lifeng, Shen Zhen, Shen Yusheng
    1987, 8(2):  151-153. 
    Asbtract ( )   PDF (223KB) ( )  
    Related Articles | Metrics
    The average aggregation number (α) of tetrabutylammonium perchloride pic-ramate disulphate and bromide salts in chloroform were determined, the average aggregation number decreases as the following order, perchloride, disulphate, bromide, picramate.
    Selectivity Studies for Molecular Seive Catalysts HZSM-5 Co/ZSM-5 and Ni/ZSM-5 (Ⅲ)--CNDO/2 Calculation for Alkylation of Toluene and the Mechanism of Isomerization of Meta-Xylene
    Wu Suochuan, Huang Jinfan, Tang Cailin
    1987, 8(2):  154-158. 
    Asbtract ( )   PDF (354KB) ( )  
    Related Articles | Metrics
    According to the mechanism of alkylation of toluene and the mechanism of isomerization of meta-xylene, which were suggested by Kaeding and Guisnet seperately, CNDO/2 method has been used to calculate the total energy of complexes in the pore of HZSM-5, Co/ZSM-5 and Ni/ZSM-5. The result can be used to explain the increase selectivity of para-xylene when the ZSM-5 modified with Co and Ni was used as catalyst. We also describe the functions of the pore of ZSM-5 and the metal atom in the pore by analyzing the diatomic interaction energy.
    Electron Structure of 3d Metal Sandwich Compounds
    Guo Chuoxiao, Shen Erzhong, Liu Juzheng
    1987, 8(2):  159-164. 
    Asbtract ( )   PDF (418KB) ( )  
    Related Articles | Metrics
    3d metal-cyclopentadienyl sandwich compounds have been analyzed in detail by EHMO procedure. The results show that the chemical bond between cyclopentadienyl ligand and transition metal, Cp-M should involve three types of σ-, π-and δ-bond, in which π-bond is pricipal component and σ, δ-bond are mainly contributed by the metal orbitals. The effect of three bond types on the stability of these compounds was also discussed.
    Investigation on The Catalytic Characteristics in the Bulk of the Keggin Type Heteropoly Acid
    Cai Tianxi, Ji Jiang, Li Luhui
    1987, 8(2):  165-169. 
    Asbtract ( )   PDF (811KB) ( )  
    Related Articles | Metrics
    The catalytic behavior in bulk of the Keggin type heteropoly acid H3PW10O40(abbreviated as HPA) has been investigated by varying amount of HPA on SiO2With the catalysts containing HPA of 5×10-5-1.5×10-1mol/(dm)3of SiO3it was found that the acid site on the surface and in the bulk of HPAshowed the same turnover frequency for the dehydration of iso-propanol. But the selectivity of catalysis in the bulk differed from that on the surface of HPA. Catalysis in the bulk favoured the formation of products with more than four carbon atoms in methanol conversion and the formation of ethylene in dehydration of ethylalcohol.
    Thermodynamic Treatment for Incomplete Exchange in Zeolite Exchangers
    Tao Zuyi, Yang Gengliang
    1987, 8(2):  170-172. 
    Asbtract ( )   PDF (224KB) ( )  
    Related Articles | Metrics
    The thermodynamic treatment for incomplete exchange in zeolite exchangers is thoroughly investigated and a set of formulas has been theoretically deduced. From the formulas mentioned above, previous theoretical formulas on incomplete exchange may be derived.
    The Preparation and Structure of Cluster Compound (Et4N)2(Mo2O3S8)
    Zhang Shiwei, Liao Daiqing, Jin Xianglin, Tang Youqi
    1987, 8(2):  173-175. 
    Asbtract ( )   PDF (216KB) ( )  
    Related Articles | Metrics
    The compound (Et4N),(Mo2O2S8) has been synthesized, and its crystal and molecular structure have been determined. The compound crystallizes in orthor-hombic, space group D2h15-Pbcawith Z= 8. The cell dimensions are α= 13.197(4)Å, b=15.739(6)Å, c = 29.033 (6)Å, α=β=γ= 90°,V = 6030(3)Å3. The compound contains terminal oxygen ligand, persulfide group (S22-), tetrasul-fide group (S42-),and (μ-S)μ-sulfide group, and has a metal-metal bond (Mo-Mo distance 2.822(3)Å).
    Cross Fractionation of Radical Initiated Methyl Methacrylate Styrene Copolymer with High Conversion
    Ye Jinyong, Luo Dexin
    1987, 8(2):  176-180. 
    Asbtract ( )   PDF (406KB) ( )  
    Related Articles | Metrics
    Methyl methacrylatc-styrene copolymers with high conversion initiated by the radical were cross-fractionated in two solvent-nonsolvent, acetone-acelonitrile and n-butyl chloridc-cyclohcxane, 35 fractions were obtained and their chemical compositions and molecular weights were determined. The results show that the application range of Stockmayer equation should include copolymer with high conversion, if a correction was made to offset the deviation due to the changs of reactivity ratios during the ccpolymerization, a chemical composition distribution curve which is basically in accord with the experimental datum was obtained.
    Synthesis and Application of Poly(Ethylene Oxide)Macromers(Ⅰ)--Synthesis and Characterization of Poly(Ethyleneoxide) Macromers with Allyl-end Group
    Sun Fang, Wu Lanting, Yang Shilin
    1987, 8(2):  181-186. 
    Asbtract ( )   PDF (317KB) ( )  
    Related Articles | Metrics
    Polyethylene oxide(PEO) macromers with allyl-cnd group were synthesized by two different methods (initiating and deactivating). The products obtained were, by means of several techniques, including 1H-NMR, IR,VPO, GPC and the double-bond titration, characterized accurately, and the results show that such kinds of product possess expected structure. The macromers were copolymerized with smalt molacular acrylamide, and a series of copolymers with different composition can be obtained by adjusting copolymerization condition. Moreover, some evidence concerning allyl-groups rearrangement in synthesis of the macromers has been observed and suitable condition for laboratorial preperation of macromers has been proposed.
    2D-NMR Studies on the Structure of Urushiol of Chinese Lacquer
    Huang Zhaogeng, Qiu Feng, You Jiang, Qian Baogong, Li Liyun, Qiu Jianqing, Yuan Hanzhen, Shen Lianfang
    1987, 8(2):  187-191. 
    Asbtract ( )   PDF (413KB) ( )  
    Related Articles | Metrics
    The urushiol diacetatcs have been successfully separated on the silica gel coated with silver nitrate by centrifugal rotation TLC. The structure and configuration of key component of urushiol (64.4%) were determined successfully by 1H and 13C conventional methods, DEPTtechnique, homo and beleronuclcar chemical shift correlation 2D-NMR, 2D-JNMR, helcronuclear relayed coherence transfer 2D-NMR, and relaxation time T1 investigation. The assignment of resonances for 1H and 13C were confirmed. Plenty of cvidence shows that the key component of urushiol is 3-(8'Z, 11'E, 13'Z-pentadccatrienyl) catechol. The results show that RELAY 2D-NMR new technique can be successfully applied to determining the structure of complicated unknown compounds.
Special Issues
More...
Download
More...
Links
More...