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    24 December 1997, Volume 18 Issue 12
    Articles
    The Choice of N-Phenyl-aza-15-crown-5 of Isopolymolybdate and Heteropolymolybdotungstate
    LU Xiao-Ming, ZONG Rui-Fa, LIU Shun-Cheng, JIN Xiang-Lin, LIU Yu
    1997, 18(12):  1911-1916. 
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    To study the effect of cyclic compounds on the structure of polyoxometalates, twonew supermolecular complexes of [Na (N-Ph)aza-15C5 (Et2O) ]2Na2Mo8O26 (Ⅰ) and [Na (N-Ph) aza-15C5(Et2O) ]2Na2W0.25Mo7.75O26 were synthesized.Their structures were character-ized by IR, 1HNMR, H,H-COSYand elementary analysis, and determined by fourcircle X-ray diffractometer.The parameters of crystal structure of supermolecule(Ⅱ) are: monoclin-ic, space group P21/c, a=1.7644(4) nm, b=l.3702(3) nm, c=1.4507(3) nm, P=114.02 (3) o, Z=2.The crystal consists of sodium N-phenyl-aza-1 -crown-5 complex cationsand two-dimensional network anions of [Na2WxMo8-x/sub>O26]2-.In comparison with the previ-ous reports, it was found that there were some relationship between the structure of thecyclic compound and the polymerization of the polyoxometalates, and the occupation of theWand Mo atoms, and the distribution of Wand Mo atoms in crystal lattice.
    Synthesis, Characterization and Structure of Tetrabenzoyloxy Bridged Binuclear Eu(Ⅲ) Complex
    NIU Shu-Yun, YANG Bing, CAO Jin-Quan, YANG Guang-Di, BU Wei-Min
    1997, 18(12):  1917-1920. 
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    The crystal of complex [Eu2(phen)2(C6H5COO)6] was synthesized and its struc-ture of the single crystal was determined by X-ray diffraction.The crystal belongs to a tri-clinlc system, space group P1, with a=1.08156(7) nm, b=1.19331(7) nm, c=1.24401(8) nm, a=104.972(5)o, g=93.661 (5)o, y=113.297(5), V=1.3994(2) nm3,Z=1, R=0.0437, Rw=0.0414.UV-Vis and IR spectra of the complex were determinedand discussed.
    Preparation and Characterization of Nanocrystalline NiO in Mixed Solvent
    LI Ya-Dong, LI Cheng-Wei, ZHENG Hua-Gui, LI Long-Quan, DUAN Xiang-Feng, QIAN Yi-Tai
    1997, 18(12):  1921-1923. 
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    NiOnanocrystalline materials were prepared by decomposing a deep green non-crystal precursor at 4OO℃.The precursor was obtained in alcohol-water mixed solvent bythe reaction of Ni(NO3)2 and NH4HCO3. XRD, TG, DTAand TEMwere used to character-ize the nanometer NiOand its precursor.The result show that the NiOfine particles arenon-agglomerated, spherical and well dispersed with the average size of 7 nm.The problemof agglomeration in c0nventional solution method is Overcomed by this convenient method.
    Syntheses of Titanates Molecular Sieves
    MA Shu-Jie, LI Lian-Sheng, HAN Chun-Ying, QIU Shi-Lun, GUO Xing-Batu
    1997, 18(12):  1924-1928. 
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    Copper titanate, sodium titanoaluminate and sodium titanate molecular sieveswere first synthesized hydrothermally with templates TPAOHand TEAOH.Their proper-ties of physical chemistry were studied and their structures were characterized by using themethods of XRD, IR, UV, SEM, DTA, NH3-TPDand gas adsorption.Catalytic activityfor copper titanate molecular sieve in which there is a structural unit of four coordinationsTiO4 was proved by the reaction of hydroxylation of phenol.
    Studies on the Coordination of Lanthanide with L-Hydroxyproline and DL-Citrulline
    GAO Feng, MA Yue-Ting, NIU Chun-Ji, NI Jia-Zuan, JIN Tian-Zhu, WANG Rui-Yao, WANG Xiang-Yun
    1997, 18(12):  1929-1931. 
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    The stability constants of binary and ternary complexes of lanthanide with L-hy-droxyproline and DL-citrulline were obtained by using potentiometric titration under thephysiological condition(37℃, 0.15 mol/L NaCl).The coordination of lanthanide with thetwo ligands was discussed.
    Hydrothermal Synthesis and Characterization of a Novel Low Temperature Phase K3Sb0.3Y4O8·6H2O
    ZHENG Wen-Jun, XU Yi-Hua, PANG Wen-Qin
    1997, 18(12):  1932-1934. 
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    Anovel low temperature phase K3Sb0.3Y4O8. 6H2Owas synthesized hydrother-mally from K2O-Sb2O3-Y2O3-H2O system, and characterized by means of XRD, SEM, IR,TG, DTAand ICPmethods- The unit cell for the product is hexagonal with the cell parame-ters a=1.6576nm and c=1.1865 nm.The volume of the cell is calculated to be 2.8233nm3.The product was decomposed into oxides from 310℃ to 390 ℃.
    Room-temperature Phosphorescence of 1-Bromonaphthalene Induced by Straight-line Alcohols in the Presence of β-Cyclodextrin
    DU Xin-Zhen, ZHANG Yongt, JIANG Yun-Bao, LIN Li-Rong, HUANG Xian-Zhi, CHEN Guo-Zhen
    1997, 18(12):  1935-1938. 
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    Room-temperature phosphorescence of 1-bromonaphthalene (1-BrN) induced byaliphatic alcohols(A) was investigated in aqueous aerated g-cyclodextrin(P-CD) solution.Itfollows that 1-BrNphosphorescence intensity initially increases with the increasing numberof the carbon atoms in an alcohol.n-Pentanol exhibits the most pronounced phosphorescenceenhancement, and subsequently the phosphorescence intensity gradually decreases from n-hexanol to n-octanol.The stoichiometry and the equilibrium constants of a ternary complexwere determined.It has been found that the binding of 1-BrNto A : P-CDcomplex is a pre-dominant factor of phosphorescence enhancement.The effect of alcohols on RTPwas ex-plained on the basis of the molecular size.
    Thermospray Nebulization as Sample Introduction for Inductively Coupled Plasma Atomic Emission Spectrometry
    ZHUANG Zhi-Xia, YANG Cheng-Long, LI Bo, YANG Peng-Yuan, WANG Xiao-Ru
    1997, 18(12):  1939-1943. 
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    Asample introduction system, thermospray nebulizer was coupled to an induc-tively coupled plasma atomic emission spectrometer.The optimization procedure includes the ICP operation conditions, the capillary temperature, the sample uptake rate, aeroso1 spraychamber temperature and the cooling water temperature.Under optimized conditions, thesensitivity for 23 elements obtained with the thermospray system is 14~25 times higher thanwith a pneumatic nebulizer- The thermospray systems have been shown to improve detectionlimits an Order of magnitude lower than that obtained with Pneumatic sample introduction.
    Enantioseparation of the Prodrug of Chloramphenicol by Capillary Zone Electrophoresis with Electrochemical Detection
    FANG Xiao-Ming, LIU Xiao-Feng, YE Jian-Nong, FANG Yu-Zhi
    1997, 18(12):  1944-1948. 
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    Chiral separation of the enantiomers of threo-2-amino-1-(4-nitrophenyl)-1, 3-propanediol, namely the prodrug of chloramphenicol (PCP), was carried out by capil1aryzone electrophoresis with electrochemical detection employing β-cyclodextrin (β-CD) as achiral additive in strong alkaline solutions.The analytes were detected by electrochemistryusing a copper disk electrode at +675 mVversus Ag/AgCl reference electrode.Both the freeenantiomers and the enantiomer-cyclodextrin inclusion complexes could be detected usingthis approach, although the complexed forms gave lower oxidation currents than the uncomplexed ones.Factors affecting the chiral CEseparation of the analytes, such as concentrationof running buffer and β-CD, applied voltage, were extensively investigated.Under the optimum conditions, baseline separation of the enantiomers could be accomplished in less than l8min.In addition, an attempt was made to elucidate the pIausible mechanism 0f the chiralrecognition.
    The Formation and Electrochemical Characteristics of Multilayer Film Electrode
    HOU Shi-Feng, FANG Hui-Qun, CHEN Hong-Yuan
    1997, 18(12):  1949-1952. 
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    Amultilayer film of polycation and polyanion complex on a thiol self-assembledmonolayer at gold electrode was presented.The electrochemical characteristics was studiedby using cyclic voltammetry.Electroactive ions such as ferricyanide and MBcan be incorporated into the multilayer and the apparent electron diffusion coefficients were detemined byusing normal pulse voltammetry.
    Calculation of the Cumulative Stabilization Constants of Cd-HA Complexes by Gradient Descent-simulated Annealing Algorithm
    YIN Hong, DENG Bo
    1997, 18(12):  1953-1956. 
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    In this paper, the cumulative stabilization constants 0f Cd-HA (Humic Acid) inthe alkali media have been studied and calculated using anode stripping voltammetry method(ASV) cornbined with GD-SAalgorithm in artificial neural network(ANN)- The molecularweight of humic acid originated from coal was determined by ASVmethod and its averagevalue is 995.2, The cumulative stabilization constants of the first and second order complexes of Cd2+-HAunder the condition of pH=10 were calculated and their values are 1gβ1=4.079 and 1gβ2=8.602 respectively.Two local minimum of objective function appear in iterative process.The values of objective function jump out from these local minimum successfully and reach to the global optimization.
    Effects of the Substitution Degree and Position of Hydroxypropyl-β-cyclodextrin on Chiral Separation of Drugs by Capillary Electrophoresis
    FU Xiao-Yun, SUN Cui-Rong, LU Jian-De, CHEN Yao-Zu
    1997, 18(12):  1957-1959. 
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    Several hydroxypropyl-β-cyclodextrins (HP-β-CDs) with various degree of substitution and different positi0n of substituti0n were synthesized.The average degree of substi-tution (Ds) of HP-g-CDwere determined by fast atom bombardment mass spectrometry(FAB-MS).The effects of the Ds of HP-β-CD on CEres0lution of four basic drugs werestudied.The results show that Ds has a different effects on the separation of various drugsbecause of different molecular structures.At Ds=0(β-CD), no separation was found for isoproterenol, of loxacin and propranolol.The resolution of both isoproterenol and ofloxacin in-creased with the increase of Ds, but decreased when Ds was 14.The best reso1ution was at Ds=10.2.The resolution of propranolol increased with increasing Ds.In contrast, the resolution of chlorophiramine decreased with the increase of Ds.The effects of the position ofsubstitution of HP-β-CDon separations were also investigated- The results demonstrate thatthe substitution at the second position of CDplays an important role in the separation ofenantiomers- ln general, the more substitution at the second position of CD, the better theseparation was obtained because the substitution of the second position made the wide open-ing become wider- This probably makes it easier for some molecular to enter the cyclodextrincavity, which c0uld facilitate enantiomeric separation.
    Screening of Anticancer Drugs by Acridine Orange cellular DNA Fluorescence Inhibition
    TANG Hong-Wu, CHEN Beit, CHEN Guan-Quant, ZENG Yun-E
    1997, 18(12):  1960-1962. 
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    Anew method for preliminary screening of anticancer drugs by Hadamard transform microscopic fluorescence image analysis was proposed.Rat liver 2c hepatocyte was usedas the standard cell and acridine orange (AO) was employed to trace the interaction of drugand cellular DNA.The results for five anticancer drugs, vincristine, cyclophosphamide,mustine, cis-platin and mitomycin-Care in accordance with the mechanism of the drugs binding to cellular DNAand this indicates that this method is suitable for screening cell cyclenonspecific anticancer drugs.
    Determination of Pyruvate in Human Serum Based on Chemiluminescent System of Ru (bipy)32+-Ce (Ⅳ)-pyruvate
    LING Lian-Sheng, HE Zhi-Ke, CAI Ru-Xiu
    1997, 18(12):  1963-1965. 
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    The reaction of Ce (Ⅳ) with Ru (bipy)32+ (bipy=2, 2-bipyridine) and pyruvate produces chemiluminescence (CL) in aqueous solution.The effect of concentration of suIfate acid, Ce(Ⅳ) and Ru(bipy) on the CLintensity was studied.The results showed that CLintensity was linearly related to the concentration of pyruvate over the range of 4.0 ×10-8,8.10×10-6 mol/Lunder the optimum conditions.The method was applied successfully to determine pyruvate in normal human serum.
    Matrix-assisted Laser Desorption Ionization Mass Spectrometry for Determination of Molecular Weight of CaMs
    LlU De-Long, ZHU Zhi-Hua, ZHAO Shan-Kai, SUN Da-Ye, YANG Yan-Sheng
    1997, 18(12):  1966-1968. 
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    The molecular weight of bovine brain CaM, intracellular CaMand extracellularCaMof cauliflower have been determined for the first time by Matrix-Assisted Larer Desorp tion Ionization Time of Flight Mass Spectrometry(MALDI-TOF-MS).The molecular weightof bovine brain CaM, 16699.9 Da determined by MALDI-TOF-MS, is closely ideatical with16700 Da, calculated from its primary sequence, showing the high accuracy of MALDITOF-MSand the conf1rmation of previously determined sequence.Furthermore, the molecular weight of intracellular CaMand extracellular CaMdetermined by MAlDI-TOF-MS, 17025 Da and 15582 Da, are in agreement with 17500 Da and 15000 Da determined by SDSPAGE-This agreement shows the high accuracy of MALDI-TOF-MS.In addition, themolecular weight of CaMs with this technique can be determined rapidly(less than 10 min)and sensitively.
    Studies on Organophosphorus Heterocycles (Ⅷ)─Cyclization of Lawesson's Reagent with the Bifunctional Substrates Containing Two Amino Groups
    HE Liang-Nian, CHEN Ru-Yu, ZHOU Ren-Xi
    1997, 18(12):  1969-1973. 
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    The cyclization of Lawesson's reagent with the bifunctional cornpounds containing two amino groups has been studied.Lawesson' s reagent reacted with 1, 2-diamines 2a-2b,1, 2-phosphinodiamides 7a-7b, and 1, 3-diamines 4a-4b in anhydrous toluene at 110℃ togive the "N-P-N" type 5-membered phosphorus heterocycles 3a-3b, 1, 3, 2, 4-di-azadiphospholidines (8a-8b) and 6-membered rings 5a-5b, respectively.In addition, LRwas treated with 1, 2, 4-triazoles at 100℃ in toluene to from cyclic compounds containingphosphorus.However, LRreacted with oximide at refluxing temperature in dry acetonitrileto give dithiooxamide, a O-Sexchange product of carbonyl, instead of the expected productformed as a result of heterocyclization.As to the formation of cyclizational products, one canassume that the electrophilic center of phosphorus of the monmetric part of LRcould attackthe nucleophilic center namely the amino group of the bifunctional substates, to form adithiophosphonamide which looses hydrogen sulfide to yield phosphorus heterocycles.Theresult of preliminary bloassays shows that all heterocycles prepared by cyclization with LRhave selective herbicidal activity.So the cyclization with Lawesson's reagent is a novel routeleading to biological active heterocycles.
    Studies on the Syntheses of Azacrown Compounds Containing Pyridine Ring and Central Fuctional Group
    HE Yong-Bing, CAI Hong-Bin, MENG Ling-Zhi, WU Cheng-Tai
    1997, 18(12):  1974-1977. 
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    Four novel azacrown compounds 12-15 were synthesized and characterized by 1H NMR, MSand elementary analysis.The synthetic method of the intermediate (7) wasstudied and improved with a significant increase of the yield.The temperature conditions ofthe cyclic reaction were investigated and the lower temperature was found to be preferable.
    Local Structural Disorder in the Organic Molecular Crystals
    LU Yang, WANG Shu-Chun, ZHENG Qi-Tai, LIU Wei, LI Fang-Hua
    1997, 18(12):  1978-1981. 
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    Five organic compounds were selected and their structures were determined by Xray diffraction.It was found that the disordered arrangement (occupying rate, position) existing in the partial atoms under the crystal state leads to the exchange in the molecular conformation, and by means of X-ray diffraction analysis, the average molecular structures are obtained.The disorder phenomena in the organic crystal structures exist universally, which make it more difficult to determine the crystal structures correctly in three-dimensional space.
    Design, Syntheses and Biological Activity of Novel Herbicides Targeted ALS(Ⅲ)─Crystal and Molecular Structure of5,7-Dimethyl-N-(substitutedphenyl)-1, 2, 4-triazolo [1,5-a] pyrimidine-2-sulfonamide
    YANG Guang-Fu, YANG Hua-Zheng, LU Rong-Jian, WANG Hong-Gen
    1997, 18(12):  1982-1986. 
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    The title compound was syntheslzed and analysed by X-ray diffraction.The difference of ortho-substituents resulted in the great difference in conformation and their herbicidal activity.Compared with the crystal structures of herbicidal sulfonurea, the same structure-activity relationship as that of sulfonurea can be found in sulfonamides, which indicatedthat this two kinds of herbicides might have the same binding site on ALS.
    Synthesis of 3-Butylidene-5-hydroxyphthalide
    LI Shao-Bai, WANG Zhi-Wei
    1997, 18(12):  1987-1991. 
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    3-Butylidene-5-hydroxyphthalide (1), isolated from Ligusticum wallichii., hasbeen first syntheslzed starting from 4-hydroxybenzoic acid in 8 steps.Herein compound 4 ondirected matallation with n-butyllithium in the presence of TMEDA followed by treatmentwith DMFgave 5 in 80% yield.The hydrolysis of 5 by employing 4 mol HCl aq.gave 6 in 83% yield.Compound 6 was converted to the acid (7) by the conventional method.Com-pound 7 was dissolved in sodium bicarbonate and reacted with a solution of iodine in aqueouspotassium iodide to give 8.Iodophthalide (8) was reacted with sodium acetate in refluxingethanol to furnish 9 in 94% yield- Demethylation of 9 was conducted in methylene chloridewith boron tribromide to give the title compound(1).The spectral data of 1 are consistentwith those of the natural product.
    Synthesis of(N-p-Tolueneslfonyl)α-aminobenzylphjosphonic Acid and Its Monoesters and Their Biological Activities
    DAI Qing, CHEN Ru-Yu
    1997, 18(12):  1992-1994. 
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    The titIe compounds were synthesized by the Mannich-type reactions involving p-toluenesulfonamide, various aromatic aldehydes and alkoxydichlorophosphine (phosphorus-trichloride) in acetyl chloride and subsequent hydrolysis.The reaction mechanism was sug-gested according to the results of 31P NMRtracing reactions- The bioassays showed thatsome of the products possess potential anti-TMVactivity.
    Studies on the Syntheses of Crown Ether Squarictelluracarbocyanines
    KE Wei-Jun, LIU Xiu-Fang, XU Han-Sheng
    1997, 18(12):  1995-1998. 
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    This paper reports the syntheses of asymmetric and symmetric crown ether squar-ictellura-carbocyanines.Both the synthesizing method and the synthesizing conditions of thelatter are discussed, and the proper mechanism of it is proposed.
    Adsorption Prperties of Nitrogen Monooxide on Metal Ion-exchanged Zeolites
    ZHANG Wen-Xiang, JIA Ming-Jun, WU Tong-Hao, SUN Tie, YAHIRO Hidenori, IWAMOTO Masakazu, JUN Izumi
    1997, 18(12):  1999-2003. 
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    The adsorption properties of nitrogen monooxide (NO) on various metal ion-exchanged zeolites were examined by adsorption-desorption measurement in a fixed bed flowapparatus.The amounts of reversible (qrev) and irreversible (qirr) adsorption of NOwerechanged with the types of metal ion and zeolite structure.Among the samples tested, thecopper ion-exchanged ZSM-5 and silver ion-exchanged mordenite showed the greatest abilityfor reversible ads0rption of NO.The amounts of reversible and irreversible ads 0rption of NOper metal ion exchanged increased with decreasing aluminum content of zeolites, and wereconstant, independent of the ion exchange level for ZSM-5 ze0lites, but changed with the ionexchange level for mordenite zeolites- It has also been found that the adsorption propertiesare dependent on adsorption temperature: qirr, increased with decreasing adsorption tempera-ture for both c0pper and silver ion exchanged ze0lites, however, qrev of Cu-ZSM-5 showed amaximum at 243 K, and qrev of Ag-MORincreased with decreasing adsorption temperature.
    Series of Studies of Vitamin K by Pulse Radiolysis and Laser Photolysis(Ⅰ)─A Pulse Radiolysis Studies of the Reduction Reaction of VK3 in Aqueous Solution
    CHEN Jia-Fu, YAO Shi-De, CHU Gao-Sheng, ZHANG Zhi-Cheng, ZHANG Man-Wei, WANG Wen-Feng, LIN Nian-Yun
    1997, 18(12):  2004-2008. 
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    The formation mechanism and subsequent reaction of anion radical of VK3, hasbeen investigated using pulse radiolysis technique.It has been observed that the anion radicalof VK3, with the maximum absorption peak round 340 nm is different from that with the max-imum absorption at 390 nm observed by others, the reasons of this difference has been ini-tially analysed.This paper also explores the protection action of VK3, to some bases of DNA,showing that VK3, itself is a good radiation protector.
    The Electronic Structure of P32(Oh) Cluster
    FENG Jian-Nan, HUANG Xu-Ri, SUN Chia-Chung
    1997, 18(12):  2009-2011. 
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    Using ab lnitio method, the electronic structure of cage-like P32 cluster with Ohsymmetry was studied.Compared with the same structure of C32, P32 (Oh) cluster showedunstability in chemical thermodynamics, but stability in chemical dynamics- The energy levelof the lowest unoccupied molecular orbital (LUMO) of P32 (Oh) cluster is negative, it isshown that the cluster is good acceptor-
    Ab Initio Studies on Directing Effects of Electrophilic Substitution for Closo Icosahedral Carboranes
    ZOU Jian-Wei, ZHANG Ming-Yu, YU Wei-Zhou, SUN Chia-Chung
    1997, 18(12):  2012-2014. 
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    Icosahedral carboranes C2B10H12, CB11H12- and the derivatives CB11H11Br-were in-vestigated by using ab initio calculations at 6-31G basis set.The analysis of populationdemonstrated that heteroatom Chas meta, para-directing effects and substituent Br is ortho, para-directing in the course of e1ectrophilic substitution of 12-vertex carboranes.Theresults are in good agreement with experimental facts.
    The Effect of Different Ratio of Carboxylic Group to Hydrocarbon Chain to Characterization of Polymaleic Acid octadecanol Ester LB Films
    JIN Jian, LI Lin-Song, HUI Zheng, LU Ran, PENG Xiao-Gang, ZHAO Ying-Ying, LI Tie-Jin, DUAN Shu-Hong
    1997, 18(12):  2015-2018. 
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    Akind of amphiphilic oligomer-polymaleic acid octadecanol ester(PMA) with dif-ferent ratios of carboxylic group to hydrocarbon chain was synthesized with polymaleic anhy-dride and octadecanol- Then as spread materials, a series of CdPMA LBfilms were preparedon the subphase containing CdCl,.With FTIRand small angle X-ray diffraction, the effectsof different ratios of carboxylic group to hydrocarbon chain and experimental conditions onthe ordered structure of CdPMA LBfilms were characterized.We concluded that, in the caseof high constant surface pressure(3OmN/m) and high dipping speed (10 cm/min), the CdP-MAwith a lower ratio of carboxylic group to hydrocarbon chain could give a high orderedpure Y-type LBfilms, while the CdPMAwith a high ratio could not.
    Theoretical Studies of Linear CnP-(n=1~11) Cluster Ions
    LIU Zhao-Yang, HUANG Rong-Bin, ZHENG Lan-Sun
    1997, 18(12):  2019-2022. 
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    Aseries of carbon cluster anions with a phosphorus atom had been produced in theexperiment.Ab initio balculations at the HF/6-311*.level were carried out on the cluster ionswith linear configuration.The calculated electronic structure, system energy and fragmenta-tion energies of six dissociation channels exhibit odd/even alternation which agrees very wellwith the experimental observations.According to the calculated results, HOMOof CnP- with odd n is full-filled bonding orbitals, so it is more stable than CnP- with even n, whoseHOMOis also doublet degenerated but it is half-filled non-bonding orbitals.The optimizedbond lengths of the cluster anions show that CusPbond of CnP- with odd n is triplet.Oncontrast, the bond of CnP- with even n is singlet, so it is easier to be broken.
    Ab Initio Study of C40, Nb@C40+ and La@C40+
    GE Mao-Fa, FENG Ji-Kang, TIAN Wei-Quan, SUN Chia-Chong
    1997, 18(12):  2023-2025. 
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    The geometric configuration and electronic structure of C40, Nb@C40+ and La@C40+were studied by using quantum chemical ab initio method.The most stable configurat1on of C40 was found to possess D2 symmetry. Nb and La atoms of Nb@C40+ and La@C40+ were insidethe C40 cage, forming endohedral metallofullerenes. Binding energy of C40, was larger thanthose of M@C40+(M=Nb, La).
    Molecular Dynamics Simulation of Diffusion Coefficients of Ar-Kr System and Its Temperature Dependence
    YAN Liu-Ming, YAN Qi-Liang, LIU Hong-lai, RONG Zong-Ming, HU Ying
    1997, 18(12):  2026-2029. 
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    Molecular dynamics simulation has been used to determine the self-diffusion co-efficients D1, D2 and mutual diffusion coefficient D12 of Ar-Kr system at different tempera-tures both from the Green-Kubo integrals over the velocity correlation function and from theEinstein relations for the mean square displacement.Good agreements were obtained be-tween the diffusion coefficients from the two methods. The temperature dependence of allthe diffusion coefficients is D=D0e-E/RT
    Additivity Rule of 31P Chemical Shifts for Thiophosphates
    ZHANG You-Jie, YANG Feng-Ling, LIU Xiao-Peng, LIU Zhai-Jie
    1997, 18(12):  2030-2033. 
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    31PNMRspectra of about 80 thiiphisphates synthesized in our laboratory weredetermined. An empirical additivity equation, a set of chemical shift parameters and stereo-electronic effect parameters, which were proposed by the authors, can be used for calculatingslPchemical shifts of phosphates and thiophosphates more accurately.The mean error andthe standard deviation between calculated and observed values of 31 Pchemical shifts are±0.096 and ±0.13 respectively. Structures of thiophosphates can be predicted by using theadditivity equation. The dependence of the 31Pchemical shifts upon electronegativity, bond-angle and stereoelectronic effect was discussed theoretically.
    Electronic Spectra of π Ion-radical Dimer of Porphyrin Derivatives
    JIANG Yue-Shun, YANG Ji-Hua, WANG De-Jun, CHEN Yong-Mei, YANG Wen-Sheng, BAI Yu-Bai, LI Tie-Jin, WANG Yong-Qiang
    1997, 18(12):  2034-2037. 
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    The electronic spectra of Kion-radical dimer of porphyrin derivatives were studiedbased on the spectroelectrochemistry of copper (Ⅱ)meso-tetrakis (4-N-methylpyridyl) por-phyrin tetrachloride salt(CuTMPyP) and the fluorescence spectra of partly protonized 5, 10,15-(4-hydroxy phenyl)-20-(4-hexadecyloxy phenyl) porphyrin (P31) LB film.The face-to-face dimer formed through the SOMO'-LUMOinteraction between the electroreducedCuTMPyPanion-radical and the ground state molecule shows Qband at 480 nm and π**band at 820 nm.The face-to-face dimer produced by the SOMO-HOMOinteraction betweenthe protonized P31 cation-radical and the ground state molecule shows the Qband absorptionat the range of 470-515 nm; and the π-π band at 710 nm.These Qbands are blue-shifted.
    EXAFS Studies on Cu/ZnO/MxOy Catalysts for Methanol Synthesis
    SHEN Bai-Rong, HAN Ji-Hong, SUN Qi, FAN Kang-Nian, GU Chang-Xin, DENG Jing-Fa
    1997, 18(12):  2038-2040. 
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    The effect of the ternary component on the structure and catalytic behavior ofCu/ZnO/MxOy catalysts for methanol synthesis from hydrogenation and carbon di0xide hasbeen studied by EXAFS.The results show that there is a relationship among the catalyticactivity, the acidity of the ternary component and the dispersity of Cu respectively.It meansthat the active site of the catalyst of this reaction should be Cu or Cu+.
    Photoionization Studies on p-Nitrotoluene with Synchrotron Radiation
    SHENG Liu-Si, WU Guo-Hua, GAO Hui, ZHANG Yun-Wu
    1997, 18(12):  2041-2043. 
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    The photoionization and photodissociative ionization processes of p-nitrotoluene(C7H7NO2) have been studied using the photoionization mass spectrometry wlth synchrotronradiation(SR) as the light source- The ionization potential (PIA) of the ionic fragment from the SRphotodissociative ionization of C7H7NO2, have been measured.Based on the mass spectra of C7H7NO2, obtained with SRpho-tolonization and the relationship of energy in the processes, the most possible channels ofphotodissociative ionization of p-nltrotoluene have been analyzed.
    Crystallization Behavior of the Novel LLDPE and Its Molecular Characteristics
    ZHAO Yong, YANG De-Cai, D. C. Bassett
    1997, 18(12):  2044-2047. 
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    Crystallization behavior of the single-site catalysed ethylene-octene-1 copolymer(LLDPE) has been investigated.The results indicate that the distribution of branches in thenovel LLDPEis more homogeneous and regular than that in materials prepared with Ziegler-Natta catalysts.However, there is still some variability in inter-branch separation.Thework has confirmed that branches trend to be excluded from crystals formed by branchedpolyethylene, but it is dependent on branch distribution and crystallization dynamics.
    Matrix Effect of Secondary Doping in Polyaniline Composite
    MA Yong-Mei, CHEN Chun-Ying, GUO Jun-Shi, XIE Hong-Quan
    1997, 18(12):  2048-2052. 
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    Secondary doping by m-cresol in polyaniline composite, which was prepared by insitu emulsion po1ymerization technique and cast from solution, was studied by UV-Vis-NIR,ESR, WAXDand so on.The po1yaniline content of the composite used in the present studyis 11.0% (wt).After secondary doping and then dedoping the composite showed a new ab-sorbance at 580~800 nm, which directly demonstrated the increase of conjugation lengththrough expanding polyaniline backbone.The difference of absorbance intensity at 600~800nm implies that polyaniline backbone can expand more completely in CSPEmatrix than inSBS.The results from ESRin situ measurement show two kinds of interaction between thecarriers of conductive backbone: after secondary doping, ESRintensity of PAn/CSPEmarkedly decreased and aΔHpp kept constant, which indicates that secondary doping inducedipolaron: secondary doping enhanced a ΔHpp of PAn/SBSfrom 3.O× 10-4 Tto 5.6 × 10-4 Tbut the intensity of ESRdid not markedly change, which means that secondary dopingcaused spin-spin interaction of polarons between conductive backbone.The results above canbe explained by phase structure of composite caused by compatibility between polyaniline andmatrix.It was found from WAXDof the composite after secondary doping that PAn/SBShad longer-range order crystal peak at 2.4.(2θ) whereas PAn/CSPEhad not.SEMwas alsotaken for composites.The results supported the difference between two kinds of compositein phase structure-
    Studies on Block Copolymers of Isotactic Polystyrene and Poly(ethylene-co-propylene) (Ⅱ) ─Fractionation and Characterization of the Block Copolymers
    CHEN Tian-Hong, LIN Shang-An
    1997, 18(12):  2053-2056. 
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    The sequential block copolymerization product of styrene with mixture of ethyleneand propylene was fractionated by successive extraction with suitable solvents.The isolatediPS-b-Poly(E-co-P) block copolymer (2O%-3O% content in total), which is s0luble in bu-tanone or chloroform was characterized by 13C NMR, FTIR, WAXD, DSCand TEMetc..This kind of copolymers containing iPSsegment are semi-crystalline diblock copolymers withspecial microphase-separation structure.
    Simplification Equation of State on Two-fluid Coordination Model for Polymer Solutions
    JIANG Wen-Hua, LIU Hua, HAN Shi-Jun
    1997, 18(12):  2057-2061. 
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    In the course of p-V-Tdata correlation by the equation of state(EOS's) on two-fluid coordination model for polymer solution.It was found that the term of Qin this EOS'Shas little influence on correlation calculation, because the Qwas dominated by hole fraction.Among polymer systems the hole fraction is much smaller than other cell fraction.So that theterm of Qcould be omitted in this EOS'Sand a simplified EOS'Swas obtained, a reducedform of this EOS's was presented and it was verified by four pure polymer systems[polypropylene, polystyrene, polyisobutylene, poly(betene-l)], two solvent systems (ben-zene, cyclohexane) and two polymer/solvent systems (polyisobutylene/benzene, poly-isobutylene/cyclohexane) that it has the same correlation accuracy as the initial EOS'Swith awide temperature range.
    Application of Digital Image Analysis to the Study of Banded Spherulite During Growing and Melting Process
    WANG Zhi-Gang, YU Dong-Hong, LUO Jun, JlANG Bing-Zheng
    1997, 18(12):  2062-2064. 
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    A digital lmage analysis (DIA) technique can be applied d1rectly t0 the image ob-tained by polarizing microscope. The time-resolved DIAapparatus including image collecting, showing and data analysis has been home-made.As an example, it has been used tostudy the banded spherulite in the blends of poly (E-caprolactone) (PCL) and poly (styrene-ran-acrylonitrile) (SAN).
    Metallocene Catalysts for Syndiospecific Polymerization of Styrene
    ZHU Fang-Ming, LIN Shang-An
    1997, 18(12):  2065-2069. 
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    Syndiotactic polystyrene was synthesised with metallocene catalysts activated bymethylaluminoxane(MAO) and trimethylaluminum (TMA).The catalytic efficlency (C.E.)for syndiospecific styrene polymerization was compared with different η5-cyclopentadi-enyltrialkoxy titanium [CpTi (OR)3].η5-Cyclopentadienyltripropoxy titanium [CpTi (O-n-Pr)3]/MAO/TMAcatalyst has a exceedingly high value of C.E.=4 × 104 g PS.(g Ti)-1.The catalytic efficiency of the catalyst and the molecular weight and syndiospecificity ofpolystyrene were affected by catalyst composition and concentration, monomer concentra-tion, polymerization temperature and time.The optlum conditions of polymerization ofstyrene for [CpTi(O-n-Pr)3]/MAO/TMAcatalyst are Al/Ti (molar ratio)=1000, tempera-ture about 60 C, high styrene concentration (>2.4 mol/L) and c(Ti)=0.14 mmol/Lformaximum activity or c(Ti)=O.18 mmol/Lfor maximum yield- The sPSwas separated frompolymerization product by extraction with boiling butanone for 8 h, the yield of sPSover95 %.
    Studies on Liquid Crystallinity of 4-Benzoyloxybenzoic Acid
    YUAN Jing, HUANG Di-Yun, JIANG Cui-Hong, ZHANG Guang-Li, ZHANG Hong-Zhi
    1997, 18(12):  2070-2072. 
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    The liquid crystallinity of the dimer of 4-benzoyloxybenzoic acid (BBA), with ex-cellent melt flow property was observed.The axial ratio (l/d) of (BBA), was calcu1ated tobe 5- 8 whlch is large enough to exhlbit Iiquid crystalline phase.The nematic phase was sta-ble at 230 C.At higher temperature(270C), the transesterification reaction occurred.Theeutectic temperature of BBAand 4-acetoxybenzoic acid is l75 C。
    The Preparation of Superfine Particle of Poly-o-toluidine in O/W Microemulsion
    GUO Rong, SONG Gen-Ping, QIAN Jun-Hong
    1997, 18(12):  2073-2075. 
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    The supra fine particles of poly-o-toluidine were prepared in (OT + O/Wmi-croemulsion) two phase system in which OTphase was used as monomer soure and the poly-o-toluidine was carried out in O/Wmicr0emulsion phase.The particle size of poly-o-tolui-dine was about 5 nm.