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Table of Content

    24 September 1996, Volume 17 Issue 9
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    Articles
    Structure Studies on Metal-Serum Albumin(Ⅸ)──A Novel Hypochromic Effect in Ni(Ⅱ)-HSA and Ni(Ⅱ)-BSA
    ZHOU Yong-Qia, TAI Jun-Zhe, LIANG Hong, OUYANG Di, LIU Hong, HU Xu-Ying, HUANG Jie-Sheng
    1996, 17(9):  1331-1335. 
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    The data of the ultra-violet spectra and the equilibrium dialysis prove that both 1:1 systems of Ni(Ⅱ)-HSAand Ni(Ⅱ)-BSAhave two strong coupling metal-centers with their LMCTbands showing a novel hypochromic effect.This effect is in consistent with the mechanism of dipole-dipole interaction between the electric dipole transition moments of chromophores.
    Solid-State Ion Exchange Between Hydrated NaX Zeolite and Alkaline Metal Salt
    YANG Chun, XU Qin-Hua
    1996, 17(9):  1336-1340. 
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    The solid-state ion exchange between hydrated 13X zealite and alkaline metal salt was studied.XRD patterns and IR spectra of the exchanged samples show that the exchange reaction can occur at ambient temperature.The exchange extent can be enhanced by repeated exchange.Compared with K+ ion, the bulky Cs+ ion is more difficult to replace Na+ ion.The calcination at a higher temperature is favourable to increasing the exchange degree of Cs+-exchanged sample.
    Synthesis and Crystal Structure of Cerium Complex of Schiff Base Cryptand
    ZHANG Ming-Jie, XIE Chun-Yan, NIE Yu-Min, CUI Rong, ZHONG Wei-Min
    1996, 17(9):  1341-1344. 
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    Amononuclear cerium complex [CeNO3·L] (NO3)2 of hexaimino cryptand was obtained by condensation of tris (2-aminoethyl) amine with 2, 6-diformyl-4-methyl phenol in the template procedure.The complex is nine-coordinate with five oxygen atoms from three phenols and a bidentate nitrate, and four nitrogen atoms from three imino C= Nbonds and a tertiary amine in the cryptand.The complex crystallized in triclinic system, space group P1, a=1.0833(3) nm, b=1.2654(4) nm, c=1.7626(7) nm, α=83.48°(3), β=89.28 (3)°, γ=83.70(3)°, V=2.386(2) nm3, Z=2.
    Studies on the Mechanism of the Chiral Metal Complexes with DNA by Fluorimetry Method
    JIN Lan, YANG Pin, LI Qing-Shan
    1996, 17(9):  1345-1348. 
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    The fluorescence characteristics of EBwhich is sensitive to DNAwas used as a probe to study the interaction of [Ni(phen)3]2+,[Fe(phen)3]2+ with DNA.The results show that the complexes bind to DNAby two models, one is the partial insertion of one of the ligands between the base pairs on the DNAduplex strand, the other is electrostatic binding by which the complexes can interact electrostatically with the phosphate backbone of DNA.
    Purification and Characterization of Silver-Induced Metallothionein in Rat Liver
    HUANG Zhong-Xian, ZHENG Qi, GU Wei-Qiang, WANG Yun-Hua
    1996, 17(9):  1349-1352. 
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    The rat liver metallothionein was induced by subactaneous injections of silver nitrate and was purified to homogeneity by using homogenization, ethanol precipitation, Sephadex G-75 chromatography and chromatography on DEAE-52.Anion exchange chromatography yielded two isoforms of metallothionein, MT-1 and MT-2, in which the molar ratios of Ag-, Zn2- and Cu+ bound are 7,2 and 2,respectively.It was also found that the ratios were slightly affected by the dose of silver nitrate, which indicate that the two endogenous essential metals, Cu and Zn, accompanying silver showed competition with the exogenous heavy metal ions.MThas different selectivities towards metals.
    Preparation of Layered Phosphatoantimonic Acid-Intercalated Manganese Porphyrin and Catalytic Oxidation of Simmulated Cytochrome
    HU Xi-Ming, PI Zong-Xin, MEI Zhi-Qian, GU Guo-Bang, HUANG Zhong-Tao
    1996, 17(9):  1353-1355. 
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    Manganese tetraphenylporphyrin as a guest molecule was intercalated in situ into the layered host material phosphatoantimonic acid.The porphyrin immobilized in the layered structure exhibits a fairly catalytic capability for the epoxidation of cyclohexene and the oxidation of n-octane by hydrogen peroxide, due to the prevention of the formation of μ-dimers.
    Structural Analysis of Condensed Polycyclic Aromatic Compounds by Tandem Mass Spectrometry
    Zeper Abliz, Takavama Mitsuo, Ueda Toyotoshi
    1996, 17(9):  1356-1360. 
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    The fragmentation mechanisrn of four isomers of pyridino and benzobenzanthrones was investigated by(EI)tandem mass spectrometry (MS/MS).The relationship between fragmentation pathways and structural characteristics was also discussed.Initial fragmentation pathways have been estimated by the intensities of fragmemt ions[M—H]+,[MHCN]+,[M—COH]+, [M—CO]i+, [M—(CO+2H)]i+and[M—(CO+HCN)]i+ produced from Mi+ (i=1,2).They indicated remarkable differences and very interesting features depending upon the isomer' s component with or without nitrogen, and also the condensation positions of a pyridino or benzo ring to the benzanthrone skeleton.The collisioninduced dissociation(CID)spectra of M2+ ion showed more effectively specific differentiation for their fragmentation behaviors reflecting the structural characteristics of these isomers.
    The Interaction of Safranine T with Anionioc Surfactant and Its Application in Labelling DNA
    GUO Xiang-Qun, LI Fang, ZHAO Yi-Bing, WANG Dong-Yua, XU Jin-Gou
    1996, 17(9):  1361-1366. 
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    The study of the properties of the visible spectra and fluorescent spectra of safranine T(ST)in the solution of anionic surfactants(AS)was reported.The results showed that STformed complex with ASmolecule when the concentration of ASwas low, and the absorbance and fluorescence intensities of ST, therefore, decreased.Anon-fluorescent dimeric dye was formed on the formation of premiceller aggregation of ASwhen the concentration of ASwas made higher, and thus the fluorescence intensity decresed dramatically,and a new peak in visible spectra appeared.When the surfactant concentration was increased above the critical micelle concentration(CMC), the dimeric dye dissociated, and a new fluophore with a high quantum yield was formed.The posibility of using the non-fluorescent dimeric dye as a fluorescent probe for deoxyribonucleic acid was also studied.The dimeric dye showed a highly DNAbinding constant and significant change of fluorescent behaviour was observed when the dimeric dye interacted with double strands DNA.It was obvious that the dimeric dye may be used as a good DNA probe.
    Studies on the Determination of Platinum for A Chitosan Chemically Modified Electrode
    WANG Yan, YE Xian-Zeng, XU Zhen-Hua, LI Nan-Qiang
    1996, 17(9):  1367-1371. 
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    A chitosan-containing glassy carbon electrode was found to give highly sensitive voltammetric wave for Pt(Ⅳ)-HCl-KCl system by anodic stripping voltammetry.Various conditions for the determination of trace Pt(Ⅳ)were studied.The optimum chitosan amount in glassy carbon was 4μLof 1%chitosan.In a solution of 0.04 mol/L HCl-KCl(pH2.2),at-0.3 Vdeposited for 2 min, scan rate was 0.2V/s, the anodic stripping potential was-0.16 V(vs.SCE).The peak current is proportional to the Pt(Ⅳ)concentration between 0.5～5.0 μg/mL,r=0.9984.0.025μg/mL Pt(Ⅳ)was determined by deposition for 10 min.The method was fairly free from interference and could be applied to the determination of platinum in precious metal ores.The possible mechanism of electrochemical reaction has been proposed by the study of CV, UVand FT-Raman spectrometry and so on.
    On Characterization of Organic Structures──A Highly Discriminating Molecular Topological Index
    HU Chang-Yu, XU Lu
    1996, 17(9):  1372-1376. 
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    A new molecular topological index, EATIis proposed based on the extended adjacency matrix.It has a hitherto unheard of power of discrimination and can be applied to discriminate various kinds of organic compounds, such as structures containing heteroatoms,etc.Thus EATI might be possibly used as supplementary reference for CAS Registry Numbers for structure documentation.
    An Investigation on Analytical Performance of Microwave Plasma Torch with a Pneumatic Nebulization Sample Introduction System
    ZHANG Han-Qi, LIANG Feng, ZHAO Xiao-Jun, LI Yong, JING Qin-Han, WANG Da-Ning, ZOU Ming-Qiang, JIA Rui
    1996, 17(9):  1377-1380. 
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    In this paper, the performance of microwave plasma torch(MPT) used as excitation sources was examined.The formation of MPT, the effects of operation parameters, sample introduction and analysis of samples were investigated.The comparison between MPTand microwave induced plasma(MIP)was performed, and the results indicate that the analytical performance of MPT is satisfactory.
    Catalysis-fluorescence Determination of Trace Iron(Ⅲ)Using Alizarin Red
    YU Ying, NIE Rui-Hua, HUANG Jian-Feng, XIE Shi-Tao
    1996, 17(9):  1381-1383. 
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    Anew catalysis-fluorescence determination method of trace iron(Ⅲ)has been de scribed by reagent alizarin red, at λex/λem=380 nm/450 nm.The experimental conditions have been optimized by multiobject punish function simplex method, which are 0.1%alizarin red 4.2 mL, 0.5 mol/L HCl 3.3 mL,saturated solution KIO4 5.7mL,temp.85 ℃,time:12.5 min, the detection limit is 0.52 ng/mL.This method is applied to determine trace iron (Ⅲ)in water sample and alloy samples with satisfactory results.
    Studies on Voltammetric Behavior of L-Cysteine at Silver Microdisk Electrode
    FANG Bin, FANG Hui-Qun, CHEN Hong-Yuan
    1996, 17(9):  1384-1386. 
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    In this paper, the voltammetric behavior of L-cysteine at silver microdisk elelectrode in 0.2 mol/L HAc-NaAc buffer solution was investigated.The mechanism of electrode reaction was discussed.The possibility of the determination of L-cysteine by cathodic stripping voltammetry was examined experimentally.The dependence of reduction peak current of Ag(L-Cys) on the L-Cys concentration in the range of 5.0×10-5～2.0× 10-3 mol/Lis linear.The method has been used for determination of mixed samples with satisfactory results.
    Studies on Enthalpies of Carbon Oxygen Bond Cleavage in Radical Ions(Ⅱ)──Bond Energies of Radical Anions
    HAN Bao-Hang, HUAN Zhen-Wei, MI Jiang-Lin, WANG Hong-Xing, CHENG Jin-pei
    1996, 17(9):  1387-1393. 
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    Three series of fossil model compounds were synthesized and their oxidation and reduction potentials were determined by CVusing BAS-100Belectrochemical analyzer.Thermodynamic cycles have been developed to determine the enthalpies of the carbon─oxygen bond cleavage of the derived radical ions.It was found that the carbon─oxygen bond is similarly activated in a thermodynamic sense by introducing an electron to the system as what was observed previously in a structurally similar radical cation, except smaller in amplitude.The carbon─oxygen bond cleavages of radical ions are all exothermic or slightly endothermic, implying a low barrier for rupture of the sessile bond,This is important to fossil fuel industry for improving traditional coal gasification routine and selecting new fragmentation path.Correlation analysis shows that plots of △Heleav[C─O]·+vs.( △BDE─△Eox[C─O]) and △Heleav[C─O]·+vs.( △Ered[C─O]+△pKa[HA]) are linear.Bond properties in relation to their structural features for both radical ions and their parent molecules are discussed and are compared with the relevant bond energy data in literature.
    Studies on the Synthesis and Structure of N-(1-Oxo-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane-4-carbonyl)-N'-aryl(alkyl)thioureas
    LI Yu-Gui, ZHU Xue-Feng, HUANG Qin, LIU Jun
    1996, 17(9):  1394-1398. 
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    Twenty-two carbonyl thioureas derivatives──N-(1-oxo-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane- 4- carbonyl)- N'- aryl(alkyl)thioureas 5a─5x were synthesized by the addition reaction of 1-oxo-4-carbonyl isothiocyanate-2, 6, 7-trioxa-1-phosphabicyclo[2.2 .2]octane 4 with various amines.The IRand 1H NMRspectra of 5 show that most of them exist in the keto-thioketo form and only a few of them have keto-thioenol tautomer.IRand 1H NMRdata also indicate that compounds 5 have intramolecular hydrogen bond.The structures of 5 were also confirmed by elementary analysis and MS.The biological activities of 5 and the crystal structure of compound 5q are being tested.
    Syntheses,DNA Intercalation Activities and Molecular Modelling on Structures of Tatramethyldifuronaphthalenes
    QIAN Xu-Hong, ZHANG Yu-Lan, XU Xiao-Yong, TAO Zhi-Fu
    1996, 17(9):  1399-1403. 
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    Dialkoxynaphthalene(2) formed from the condensation of 2, 7-dihydroxynaphthalene(1) with 3-chloro-2-butanone, refluxed in POCl3/CCl4 to give cyclized products of 73% asymmerical 4 and symmetrical tetramethyldifuronaphthalene 5.In the presence of hydrochloride,2 was partly cyclized to give 3,followed by cyclization at room temperature in acetylacetate/methylenechloride under the action of BBr3 to give only symmetrical product 5.The structures of all products was fully characterized using IR,UV,FL,1H NMR,13CNMR, MSand elementary analysis,It was found that 4 can intercalate into Calf Thymus DNA,but 5 couldn't, and the apparrent intercalation constant for 4 was recorded.Using molecular modelling study,not only the bond lengths and angles of 5 were calculated well, but also it is indicated that the difference in DNAintercalation activity between 4 and 5 mainly depends on that in their molecular planarity.
    Studies on Synthesis of Monosaccharide Esters Catalyzed by Lipases in Organic Solvents
    ZHANG Nian-Xiang, CAO Shu-Gui, DONG Huan, LIU Yan-Bin, REN Yi-Qing, HAN Si-Ping, YANG Hong
    1996, 17(9):  1404-1407. 
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    The synthesis of monosaccharide ester catalyzed by lipase in organic solvents was studied,where monosaccharides and vinyl acetate or acetic anhydride serve as substrates.Quantitative and qualitative methods for determination of monosacchride ester were developed.The activities of lipases from different sources catalyzing synthesis of monosacchride ester were compared and lipase from Pseudmonus S.P.Lipase(PSL1) was the best.We also studied the selectivity of PSL1 to different monosaccharide substrates and found mannitol is the most efficiency substrate to PSL1 and the conversion can reach 95%.The effects of water content in the system,temperature and lipase concentration on the reaction were studied.
    Crystal Structure of Strontium 2-Furancarboxylate
    YANG Zhong-Lu, CHEN Chang-Lin, YU Kai-Bei
    1996, 17(9):  1408-1411. 
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    The single crystal of strontium 2-furancarboxylate Sr6(C5H3O3)12has been synthesized and grew in the aqueous solution and characterized by elementary analysis,IRspectra,density,DTAand TG,The structure of this compound is determined by X-ray single crystal diffraction analysis.The crystallographic data are as follows:monoclinic,space group P21/n,a=2.3090(7)nm,b=1.3376(4)nm,c=2.3093(6)nm,β=107.06(2)°,Z=4,R =0.0603.Dc=1.82×103 kg/m3,Dm=1.81×103 kg/m3.The 2-furancarboxyl groups in the compound are connected with the strontium ions through the oxo-bridging and then three-dimensional network is fromed.The average value of bond length of Sr─Ois 0.2641nm;but they are 0.2535 nm and 0.2861 nm when the oxygen atoms are from carboxyl group and furan nucleus respectively.
    Reations of 6,6-Dialkylfulvenes with Benzylsodium──Synthesis of Suhstituted Titanocenes and Zirconocenes
    YANG De-Yu, HE Zheng-Jie, CHEN Shou-Shan, WANG Jia-Xi
    1996, 17(9):  1412-1415. 
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    Dialkylfulvenes and 6,6-polymethyleneftilvenes only undergo exocyclic double-bond addition with treatment of benzylsodium.Twentv-two novel titanocenes and zirconocenes with chiral or achiral substituents have been synthesized by complexation of substituted cyclopentadienyl anions obtained from the above reactions with TiCl4, ZrCl4 or (CpTiCl2)2O.Reaction mechanism and 1H NMRspectra have been discussed.
    Studies of the Synthesis and Antitumor Activity of 5-Fluorouracil Derivatives Containing D-Aminoglucose Residue
    LUO Xuan-Gan, ZHUO Ren-Xi, LI Man-Qing
    1996, 17(9):  1416-1420. 
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    This investigation describes the effect of D-aminoglucose on the antitumor activity of 5-fluorouracil.By choosing α-amino acids as connective group, we have synthesized 4 kinds of 5-fluorouracil derivatives containing D-aminoglucose residue.Their structures were confirmed by 1H NMR,IR, UVspectra and elemental analysis.The data of activity against the isolated ehrlich ascites tumor cells in vitro has been evaluated.The preliminary results show that these compounds all exhibit much better antitumor activity than 5-fluorouracil it-self does.
    Stereochemical Effect in Mass Spectrometry(19)──Determination of the Optical Purity of α-Phenylethylamine by Mass Spectrometry
    WU Yi-Nan, TU Ya-Ping, PAN Yuan-Jiang, CHEN Yao-Zu, CUI Meng, SONG Feng-Rui, LIU Shu-Ying
    1996, 17(9):  1421-1423. 
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    It is found that in the fast atom bombardment(FAB) mass spectra R-α-phenylethylamine and S-α-phenylethylamine can be clearly distinguished by S-1,1'-binaph thyl-2,2'-Jiylhydrogenphosphate(S-BNP).Mixture of R-α-phenylethylamine and S-αphenylethylamine also be tested and the relative abundance of the characteristic ion of mixture is related to the composition of the mixtute.We have therefore proposed a possible method to determine the optical purity of α-phenylethyiamine.
    A Study of the Spectra and Photophysical Behavior of 2-Aryl-benzoxazole
    PENG Zhao-Kuai, YANG Guo-Qiang, WU Shi-Kang
    1996, 17(9):  1424-1427. 
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    The spectra and photophysics of 2-aryl-benzoxazole derivatives have been studied in this work.The obtained results indicate that the photophysical behavior of these compounds is different evidently from those of usual intramolecular conjugated charge transfer compounds and the cause of these differences are discussed and analyzed.In addition,the results also show that the higher fluorescence quantum yields of these compounds are concerned closely in the twist inhibition of the C＝N double bond in the molecules.
    The Interaction Mechanism of Al-Mg MMH Sols with Na-montmorillonite Suspensions
    SUN De-Jun, HOU Wan-Guo, ZHANG Chun-Guang, HAN Shu-Hua, WANG Guo-Ting
    1996, 17(9):  1428-1432. 
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    The effects of inorganic salts(NaCl,KCl and CaCl2)and pHvalues on the interaction between Al-Mg MMHsol(aluminum magnesium mixed metal hydroxides)and Na-montmorillonite(Na-Mt)suspensions have been studied by the measurments of rheology,electrophoretic mobility and pH.The results show that the increase of MMHin Na-Mt suspensions produced an increase in YP(yield point)at first and then a decrease after a maximum but a gradual decrease in pH.The results are interpreted as meaning that the MMHsols can interact with Na-Mt suspensions through an ion exchange mechanism.In the presence of saturated NaCl,a much less change of YPand no YPmaximum under the experimental concentrations of MMH can be explained by DLVOtheory.Due to the effects of pHon ion exchange reaction the change of YPwith pHof MMH/Na-Mt systems is in terms of parabolic curve.Inorganic salts lower YPand pHin the order of CaCl2>KCl～NaCl,and the order is found to be consistent with that for experimental estimates of the number of unit layers in face-to-face association.This would imply that the metallic ions must function as the exchangeable cations.
    The 151Eu Mossbauer Study for Double Perovskite REEuCr2O6
    LI Li-ping, KANG Zhi-Jian, WEI Quan, SU Wen-Hui
    1996, 17(9):  1433-1436. 
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    Double perovskite oxides REEuCr2O6(RE=La, Pr, Nd, Sm, Gd ,Tb ,Dy, Ho,Er, Tm)were prepared by solid state reaction method.The measurement of XRD, IRand 151Eu Mössbauer spectra show that all samples are orthorhombic structure; as the atomic number of REincreases, the cell volumes decrease.The relationship between isomer shift and Vis linear,Quadrupole splits are negative,and with atomic number of REincreasing,their absolute values increase.
    Liquid Membrane Transport Properties of Metal Ions by Crown Modified Polymethylsiloxanes
    GONG Shu-Ling, ZHANG Bao-Lian, LU Xue-Ran, CHEN Yuan-Yin
    1996, 17(9):  1437-1440. 
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    Two new types of crown modified polymethylsiloxanes were synthesized.The cation transport rate through a bulk liquid membrane containing crown modified polysiloxanes was reported.The stability of the membrane was also investigated.
    A Study of Highly Active Titanocene/n-BuLi Catalyst System in the Hydrogenation of Olefin
    SUN Qi, LIAO Shi-Jian, XU Yun, ZHANG Yi-ping, YANG Ren-Wu, SUN Ren-An, CHEN Shou-Shan
    1996, 17(9):  1441-1445. 
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    The effects of substituted group on the cyclopentadienyl ring and various operating factors including the amount of catalyst, the operating procedure,the solvents, the airand water-free conditions on the catalytic activity and stability of titanocene/n-BuLi catalyst system have been investigated.When there is no substituted group on the cyclopentadienyl ring or the substituted group is relatively small,the titanium complex exhibits a very high initial catalytic activity,e.g., the TOFmax(or TOFinitial)of titanocenes {Cp2TiCl2,Cp2TiF2 or Cp2Ti[OC6H3(CH3-2)Cl-4]2}/n-BuLi system may reach 46～58 s-1 for the hydrogenation of l-octene; whereas when the substituted group is larger,the titanium complex exhibits a lower initial catalytic activity but better stability.
    Studies on the Properties of Lyotropic Liquid Crystal for As/n-C5H11OH/H2O System with 2H NMR and DSC Methods
    LI Fang, LI Gan-Zuo, WANG Han-Qing, HAO Shu-Xuan
    1996, 17(9):  1446-1449. 
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    The isothermal phase diagram for the system sodium dodecyl sulfonate(As)/n-C5H11OH/H2Ohas been determined at 303 K. 2H NMRspectroscopy and DSCmethod have been used to determine the structures of the lyotropic liquid crystal.The results showed that the liquid crystal structures did not change with the contents of water under a certain temperature(303 K),but changed with the variation of temperatures at a certain composition.
    Studies on Three-Dimensional Quantitative Structure-Activity Relationships Between the Structures of N-Nitroso Compounds and Their Carcinogenic Activities
    LI Hua, XU Lu, SU Qiang
    1996, 17(9):  1450-1453. 
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    Comparative molecular fiels analysis(CoMFA)has been applied to the studies of the correlation of the N-nitroso compounds and their carcinogenic activities.The comparison of CoMFAresults with different lattice spacing and different atom probes was investigated.CoMFAresulted in a quantitative description of the major steric and electrostatic field effects and gave significant new insights to factors governing potency.
    Pore Structure,Surface Acidity and Catalytic Activity of Ti-Silicalite Prepared by Different Methods
    CHEN Guo-Hui, XIA Qing-Hua, GAO Zi
    1996, 17(9):  1454-1457. 
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    Ti-ZSM-5 and TS-1 zeolites were prepared by vapor-solid isomorphous substitution and hydrothermal synthesis methods respectively.The chemical composition, pore structure,surface acidity and catalytic activity of the two types of Ti-containing zeolites with MFIstructure were tested and compared.TS-1 zeolites obtained from hydrothermal synthesis with tetraalkyl ammonium halides as templates have a higher Ti content in the zeolite framework and lack of strong acid sites on the surface.As the amount of Ti incorporated into the zeolite framework is increased,the size of the hysteresis loops on the N2 adsorption and desorption isotherms is also increased,implying that more secondary mesopores are formed in the zeolite from the lattice defects.The Ti content of the isomorphous substituted Ti-ZSM-5 zeolites is limited,and a part of Al still remains in the zeolite framework.Both weak and strong acid sites exist on the surface of Ti-ZSM-5 zeolites.An increase in the Ti content and the secondary pores in the zeolite lattice is in favor of its catalytic activity for the oxidation of phenol with hydrogen peroxide, but the presence of surface strong acid sites reduces its catalytic activity and selectivity for the same reaction.
    Theoretical Studies on the Structure and Vobrational Spectra of B2C3 Cluster
    GE Mao-Fa, FENG Ji-Kang, HUANG Xu-Ri, YANG Cheng, SUN Chia-Chung
    1996, 17(9):  1458-1461. 
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    The B2C3 cluster was studied by using quantum chemical ab initio method.Various possible structures, related vibrational spectra and binding energies were calculated.The electronic structure of the most stable configuration of the B2C3 cluster was analyzed and discussed in detail.
    Dispersion of C60 in Mixed Langmuir Monolayers of Porphyrin/C60
    LIU Hong-Guo, FENG Xu-Sheng, YANG Kong-Zhang
    1996, 17(9):  1462-1466. 
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    The dispersing states of C60 molecules in mixed monolayers of TDPP/C60(1:1) and TAPP/C60(1:1)have been studied in this paper,Here,TDPPdenotes 5,10,15,20-tetra-4-oxy(decanoic acid)phenylporphyrin, and TAPPdenotes 5,10,15,20-tetra-4-oxy(acetic acid)phenylporphyrin,The π-A isotherms of mixed monolayers on air/Cd2+ aqueous solutioninterface, the low angle X-ray diffraction results of the alternate multilayers of TDPPor TDPP/C60 with arachidic acid and the UV-Vis spectra of mixed LBmonolayers show that,in the mixed TDPP/C60 monolayer C60 aggregates or(and) single C60.molecules are incorporated into the cavities of TDPPmolecules containing long alkyl chains,.but in the mixed TAPP/C60 monolayer, C60 aggregates distribute among the TAPPaggregates.
    Studies on the Cationic Copolymerization of α-Pinene and Styrene with the AlCl3 /SbCl3 Catalyst
    DENG Yun-Xiang, PENG Chao-Pan, DUAN Wen, ZHANG Ren-Jun, ZENG Long-Mei
    1996, 17(9):  1467-1472. 
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    The copolymerization products of a-pinene (M1) and styrene(M2)were prepared with the catalyst system SbCl3/AlCl3 by changing the Sb/Al ratio, feeding monomer ratio,solvent and polymerization temperature.The compositions of the copolymerization products were quantitatively characterized by the method of the combination of micro-ozonization and thin-layer chromatography in terms of the contents of the homopolymers and the copolymers.The results show that it was easier to obtain the higher yield(up to 80%)of the pure copolymer with the complex catalyst system than with AlCl3 alone.The F1 values could be controlled between 30%～56%.The monomer reactivity ratios were determined under the polymerization conditions under which only pure copolymer of M1 and M2 was given by using Mayo-Lewis equation.The effects of various catalyst systems and polymerization conditions on the reactivity ratio were also investigated and it was found that the r1 increase from 0.19 to 0.22～0.24 with the AlCl3/SbCl3 instead of AlCl3,but the r2 decrease significantly(from 5.00 to 1.20～1.92).On account of the r2/r1 value is decreased 4～6 times,the copolymerization of M1/M2 was changed into carried out with ease.It was supposed that this good copolymerization activity is attributed to its nonprotonic active species and the characteristic of the counteranion's structure.
    Polymerization of MMA Initiated by PVC with Pendent N,N-Diethyldithiocarbamate Groups Under UV-Irradiation
    YANG Wen-Jun, GUAN Jian-Jun, YE Shu, CUI Wei-Guo, SHEN Jia-Cong
    1996, 17(9):  1473-1476. 
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    The PVCcontaining N,N-diethyldithiocarbamate groups(PVC-SR)was prepared by the substitution of sodium N, N-diethyldithiocarbamate on the partial chloride of PVCand used to initiate the polymerization of MMAunder UV-irradiation.The effects of irradiation time, concentration of monomer, amount and degree of functionality of PVC-SR on the polymerization were investigated.The results showed that PVC-SRcould efficiently initiate the photopolymerization of MMA to form crosslinked graft copolymers which had a high grafting efficiency and a high degree of gel .
    Synthesis of Polystyrene with C60 in the Side Group
    WANG Chang-Chun, SHU Chang, FU Shou-Kuan
    1996, 17(9):  1477-1481. 
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    Three-step reactions,i.e.,chloromethylation,azidization and cycloaddition,were adopted to introduce C60 into the side group of polystyrene successfully, and each step reaction was discussed in detail.The products were proved to be extremely soluble in a variety of organic solvents such as CHCl3, THF, etc..This solubility behavior is simillar to polystyrene itself and totally unlike C60.
    The Morphology and Structure of Multi-component Polyurethane Macroporous Adsorbents
    SHI Lin-Qi, He Bing-Lin
    1996, 17(9):  1482-1486. 
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    The polyurethane macroporous segmented copolymers were synthesized by two step polymerization.The products were investigated by FTIR, DSCand SAXS techniques .The results show that the structure of macroporous adsorbents is as expected.As the specific surface area and pore diameter data are concerned, they have comparable physical properties to commercial porous polymers.The morphology of polyurethane macroporous copolymer is three domain structures, which would be beneficial to the adsorption behavior and selectivity of adsorbents.
    NMR Investigation of Phenolphthalein Polyether ether ketone(Ⅰ)──The Chain Structure and Assignments of 1H, 13C NMR Lines of PEK-C
    ZHANG Jian-Guo, PEI Feng-Kui
    1996, 17(9):  1487-1491. 
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    Amorphous samples of polyether ketone with cardo(PEK- C)have been studied in the solution state by 13C,1H high-resolution NMR.The 1H and 13C 1D NMR spectra were assigned using two dimensional chemical shift correlated spectroscopy.2D homonuclear correlated(COSY)and heteronuclear correlated (HETCOR)spectroscopy present important information.In this work, the structural units of PEK-Cwas determined by NMR.For some peaks, these assignments are confirmed by two dimensional long-range heteronuclear correlation experiments, Alittle modification is made on the original 13C peak assignments for the main chain.The symmetry and the isotacticity of the chain structure for PEK -Care obvious on NMR data.
    Studies on Chain Transfer to Succinic Anhydride of THF Polymerization
    LI Fang-Xing, MA Ke-Qin, CHEN Yan, WEN Jia, HUO Yu-Jie
    1996, 17(9):  1492-1494. 
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    During the polymerization process of THF, active center can transfer to succinic anhydride and produce polyether-ester block copolymer.If TDIis added into the system,the relative velocity of polymerization and chain transfer reaction can be controlled.It is found that when the molar ratio of TDI/catalyst is 1, the polymerization can be accelerated, while the transfer rate decreases during the latter period of the reaction .However, when this ratio is 5/1, the propagation rate changes little, but the transfer rate increases.In the systems without TDI, with one time and five times moles of TDIas the mole of catalyst at 8℃, the apparent propagation rate constants of THF, kp are 5.55×10-3,7.10× 10-3 and 8.10×10-3 L/(mol·s), respectively; the transfer rate constants ktr are 1.33 × 10-3,0.43 × 10-3 and 5.55×10-3 L/(mol·s), respectively.
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