Table of Content

24 January 2001, Volume 17 Issue 1

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Articles

NMR Studies of a New Binding Mode of the Amino Acid Esters by Porphyrinatozinc(Ⅱ)

PENG Xiao-bin, HUANG Jin-wang, LI Tao, JI Liang-nian

2001, 17(1):  1-5. 

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The binding mode of the amino acid ethyl esters(guest) by 5-(2-carboxylphenyl)-10,15,20-triphenylporphyrinatozinc(Ⅱ)(host 1) was studied by means of ¹H NMR spectra. The binding mode is the hydrogen-bonding between the amino group of the guest and the carboxyl group of host 1 plus the coordination between the zinc atom of porphyrinatozinc(Ⅱ) and the carbonyl group of the guest. This is a novel binding mode of the metalloporphyrin to amino acid derivatives.

Binding Constants for Terbium(Ⅲ) with Chicken Apoovotransferrin

YANG Bin-sheng, LI Ying-qi

2001, 17(1):  6-13. 

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The binding of Tb³⁺ to chicken apoovotransferrin was studied by monitoring the fluorescent intensity of Tb³⁺ at 549 nm. The conditional equilibrium constants for the complexation of Tb³⁺ by chicken apoovotransferrin in 0.1 mol/L hepes, at pH 7.4 and room temperature were measured. The successive macroscopic binding constants are lgK₁=9.08±0.12 and lgK₂=7.36±0.22. The molar fluorescence enhancement of Tb³⁺-apoovotransferrin complex is (2.06±0.14)×10⁴ mol^-1·L. The fluorescence quenching experiment and the titration of N-terminal monoferric ovotransferrin showed that Tb³⁺ has a preference for being bound to the N-terminal binding site of apoovotransferrin.

Synthesis, Crystal Structure and Reactivity of (2,4-C₇H₁₁)₂Yb·DME

ZHANG Suo-bo, LIU Ju zheng, ZHUANG Xiu-li, HUANG Jing-qin, HU Ning-hai, CHEN Wen-qi

2001, 17(1):  14-19. 

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(2,4-C₇H₁₁)₂Yb·DME was synthesized by the reaction of YbCl₃ with K(2,4-C₇H₁₁)(2,4-dimethylpentadienyl potassium), and the single crystal X-ray diffraction showed that the complex exists in a cis- staggered conformation. The crystal of the compound belongs to the monoclinic space group P2₁/n with a=0.875 2 (1)　nm, b=1.490　6(1)　nm, c=1.529　3(2)　nm, β=97.55(2)°, V=1.977 79(4)　nm³, Z=4, F(000)=735.8 e, μ=49.49　cm^-1, R=0.033 and R_w=0.032.　The title complex can be used as a catalyst for the polymerization of methyl methacrylate(MMA).

Synthesis and Characterization of Zinc Succinate, Zn(C₄H₄O₄)

ZHENG Yue-qing, PET ERS Karl, von SCH NERING Hans Georg

2001, 17(1):  20-25. 

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Zn(C₄H₄O₄) prepared by dissolving 0.483 g (1.41 mol) of Zn₃(OH)₄CO₃·H₂O and 0.5 g (4.23 mol) of C₄H₆O₄ in 50 mL of H₂O followed by slow evaporation at room temperature crystallizes in the monoclinic space group C2 with the cell parameters a=0.757　9(1) nm, b=0.597　6(1) nm, c=0.626　5(1) nm, β=108.45(1)°, V=0.269　17(7) nm³, D_x=2.239g/cm³, Z=2 and the final R(F_o)=0.039 and wR(F_O²)=0.088 for 396 reflections ［F_O²≥2σ(F_O²)］. In the crystal structure unit, each Zn is tetrahedrally coordinated by four O atoms from four (C₄H₄O₄)^2- anions, each of which, in turn, bridges four Zn atoms to build up a 3D³_∞［Zn(C₄H₄O₄)_4/4］ network. The thermal analyses indicate that Zn(C₄H₄O₄) is stable below 420 ℃.

In-situ Microscopic FT-IR Spectroelectrochemical Investigation of Polythiophene Film Modified Electrode

JIANG Jun-guang, ZHANG Hong-qiang, LIN Xiang-qin

2001, 17(1):  26-30. 

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A polythiophene film was electrochemically deposited on a Pt micro-plate electrode and investigated by cyclic voltammetry and in-situ reflection microscopic FTIR spectroscopy. The FTIR analysis showed that the electropolymerization of thiophene on the Pt surface was affected by the surface adsorption processes of thiophene molecules. Two adsorption modes were identified. Two structure models of the polythiophene chain were observed simultaneously. It was proposed that the good conductibility of the polythiophene film was originated from a co-vibratory equilibrium of the link part of model Ⅰ and model Ⅱ.

Estimation and Prediction of Gas Chromatography Retention Indices of Hydrocarbons in Straight-run Gasoline by Using Artificial Neural Network and Structural Coding Method

YIN Chun-sheng, GUO Wei-min, LIU Wei, ZHAO Wei, PAN Zhong-xiao

2001, 17(1):  31-40. 

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The molecular structures of hydrocarbons in straight-run gasoline were numerically coded. The nonlinear quantitative relationship(QSRR) between gas chromatography(GC) retention indices of the hydrocarbons and their molecular structures were established by using an error back-propagation(BP) algorithm. The GC retention indices of 150 hydrocarbons were then predicted by removing 15 compounds(as a test set) and using the 135 remained molecules as a calibration set. Through this procedure, all the compounds in the whole data set were then predicted in groups of 15 compounds. The results obtained by BP with the correlation coefficient and the standard deviation 0.993 4 and 16.54, are satisfied.

Catalytic Kinetic Determination of Micro Amounts of Oxalic Acid by Second-Order Derivative Oscillopolarography

LI Li-jun, HONG Zhe

2001, 17(1):  41-47. 

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It was found that micro amounts of oxalate showed a very strong catalytic effect on the slow reaction between K₂Cr₂O₇ and Orange Ⅳ in a diluted sulfuric acid medium in a water bath at 70 ℃. Orange Ⅳ exhibited a sensitive second-order derivative polarographic wave at -0.50 V(vs. SCE). This provides the basis for a sensitive and selective catalytic kinetic method for oxalate determination with second-order derivative oscillopolarography. The effects of sulphuric acid, K₂Cr₂O₇, and orange Ⅳ concentrations, reaction temperature and reaction time were investigated. A calibration curve of oxalate in the range of 0.1—2.0 μg/mL was obtained by the fixed-time procedure. The detection limit was 0.03 μg/ mL. The possible interference from co-existing substances or ions was examined. The new method has a high sensitivity and a good selectivity compared to other existing methods for oxalic acid determination. It has been applied to the determination of micro amounts of oxalate in real urine samples with satisfactory results.

A New Flavonol Glycoside from Anaphalis sinica Hance

ZHOU Yi, ZHANG Guo-lin, LI Bo-gang, CHEN Yao-zu

2001, 17(1):  48-50. 

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A new flavonol glycoside, 5,7,3',4'-tetrahydroxy-3-methoxyflavonol-3'-O-β-D-glucopyranoside(1) was isolated along with quercetin(2), quercetin-3-O-α-L-rhamnopyranoside(3), quercetin-3-O-β-D-glucopyranoside(4) and kaempferol-3-O-β-D-(6＂-O-p-coumaroyl)-glucopyranoside(5) from Anaphalis sinica Hance. Their structures were determined on the basis of spectral data(MS, UV, IR, ¹H and ¹³C NMR). The structure of compound 1 was confirmed by X-ray crystallographic analysis.

Synthesis of the Stereoisomers of the Sex Pheromones of the Southern Corn Rootworm

HUANG Jin-xia, LI Yan, ZHOU Zhong-qiang, YUE Xia-li

2001, 17(1):  51-55. 

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A simple and efficient asymmetric synthesis of the sex pheromone of the southern corn rootworm is discribed. The key step is the asymmetric Michael addition of enoylsultam with virtually complete asymmetric induction(e.e.%＞99%)

Synthesis and Structure of N-(E)-Enoyl(-)-bornane-10,2-sultams

LI Yan, CHEN Liao-rong, ZHOU Zhong-qiang, HUANG Jin-xia

2001, 17(1):  56-62. 

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Two potential chiral auxiliaries, N-(E)-enoyl(-)-bornane-10,2-sultams, were synthesized from (-)-bornane-10,2-sultams. The molecular crystal structures of the title compounds were determined by diffraction analysis. The crystal of C₁₆O₃SNH₂₅ belongs to a rhombic system, the space group is P2₁2₁2₁ with cell parameters: a=0.734 6(7) nm, b=1.142 7(3) nm, c=2.009 7(3) nm, β=90.00°, V=1.686 9 nm³, Z=4, D_c=1.250 g/cm³, μ=1.926 cm^-1 and F(000)=672. The crystal of C₁₅O₃SNH₂₃ belongs to a rhombic system, the space group is P2₁2₁2₁ with cell parameters: a=0.738 2(2) nm, b=0.921 6(1) nm, c=2.280 9(8) nm, β=90.00°, V=1.551 7 nm³, Z=4, D_c=1.273 g/cm³, μ=2.504 cm^-1 and F(000)=640. The structural characteristics with respect to the potential utility for the stereoselective Michael addition reaction of the N-enoyl group are discussed.

Syntheses and Structural Characterizations of η⁵-2,4-Cyclopentadien-1-yl Di-carbonyliron Heteronuclear Bi-Metallic Complexes

GAO Jin-sheng, MA Zhong-guo, YE Ling, BU Wei-ming, MA Dong-sheng, YU Chang-hua, GE Yue, FAN Yu-guo

2001, 17(1):  63-68. 

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The novel complexes, Cp(CO)₂FeTiCp₂Cl(1) and Cp(CO)₂FeSn(CH₂CMe₂Ph)₃(2), were synthesized and characterized by means of elemental analyses and IR spectra, Cp(CO)₂FeSn·(CH₂CMe₂Ph)₃ was additionally characterized by X-ray crystal structure analysis. The results of the elemental analyses are in good agreement with the theoretical values. The IR spectra show the existence of η⁵-2,4-cyclopentadien-1-yl, carbonyl and methyl groups in the title complexes. The above experimental results show that the M—M'bond exists in Cp(CO)₂FeSn·(CH₂Me₂Ph)₃, while the existence of the M—M'bond in Cp(CO)₂FeTiCp₂Cl is highly possible, too. Both the two complexes are rather stable towards air and moisture, easily soluble in tetrahydrofuran and toluene, while their solubilities are greatly different in n-hexane.

Synthesis of 7-Ethyl-10-hydroxycamptothecin and Proposed Reaction Mechanism

LEI Ying-jie, ZHU Chun-hua, WANG Zuo-quan, LIU Hong

2001, 17(1):  69-72. 

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The improved 3-step preparation of a key antitumor agent, 7-ethyl-10-hydroxycamptothecin(SN-38), which consists of ethylation, oxidation and photo-chemical rearrangement, is described. The proposed reaction mechanism is also discussed.

Mechanisms of Cytochrome C Extraction by Reverse Micelles

YU Yan-chun, QIAN Bao-hua, CHU Ying, WU Zi-sheng, GAO Chang-qing

2001, 17(1):  73-76. 

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The extraction of cytochrome C was carried out by means of phase transfer technique with three different reverse micellar systems, i.e., a CTAB micellar solution in n-butyl alcohol-chloroform(volume ratio 4∶1), an AOT micellar solution in isooctane and a SDSS-D₂EHPA micellar solution in isooctane. The extraction mechanisms were studied. The results show that the extraction mechanisms for the same proteins with different types of reverse micellar systems can be distinct. The extraction of cytochrome C with CTAB and SDSS-D₂EHPA reverse micellar systems are carried out according to the mechanism of electrostatic interaction. However, in the extraction of cytochrome C with the AOT reverse micellar system, the electrostatic interaction between the protein and the surfactant is not important.

A Study on 4,4′-Diaminobenzene Sulfonanilide(DABSA) and the Properties of Dyes Derived from DABSA

WU Zu-Wang, WANG Li-Min, DAI Jian-Ying, WANG Shi-Rong, XIAO Jin-Qiu, LIU Xiu-Mei, HAN Xiu-Wen, ZHAO Qi, BAO Xin-He

2001, 17(1):  77-87. 

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A single crystal of 4,4′-diaminobenzene sulfonanilide(DABSA) was determined by X-ray diffraction method. It is shown that the two benzene rings are non-planar with an angle of 55.1°. Owing to the non-planar configuration, the dyes derived from DABSA possess a lower substantivity on fiber but better permeability in substrate, the color of these azo dyes could be matched by two individual azo dyes locating on both sides of the DABSA molecule.

On the Energy Transfer of a Colinear OH+ O System

WU Tao, CHEN Xian-yang, PENG Jian-bo, JU Guan-Zhi

2001, 17(1):  88-94. 

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A quantum mechanical calculation was performed to study the Translation-Vibration(T-V) energy transfer of a colinear OH+O/OD+O system, for which Delves' coordinates and R-matrix propagatation methods were applied to a Mulius-Blint potential energy surface. The calculated result of the T-V energy transfer probability shows strong oscillation phenomena and the collision delay time of the title system was in the 10^-15—10^-12 s time scale. The kinetic isotope effect was discussed in this work too.

Effects of Pressure, Solvent, and Substituenton the Thermal Isomerization of 2-Oxo-spiro［diazirine-3,3'-indoline］

Yoshimi Sueishi, Genta Okazaki

2001, 17(1):  95-101. 

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The kinetic effects of pressure, solvent, and substituent on the thermal isomerization from 2-oxospiro［diazirine-3,3'-indoline］ to 3-diazo-2-oxo-indoline have been examined. The rate constants of the thermal isomerization increased with increasing external pressure and were related to the σ+P substituent constant of Hammett correlation. The results suggest that the thermal isomerization proceeds via a dipolar transition state involving heterolytic bond fission. However, the kinetic solvent effects on the thermal isomerization were not observed. The special solvent effects were discussed on the basis of the linear free energy relationship.

Investigations of Thallium(Ⅰ) Underpotential Deposition on the Silver Rotating Disk Electrode and Its Analytical Application

WANG Chun-ming, ZHU Li

2001, 17(1):  102-107. 

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The cyclic voltammetry(CV) and the square-wave technique were used for the investigations of thallium(Ⅰ) underpotential deposition(UPD) on the silver electrode. A solution of 10 {mmol/L} HClO₄+ 10 mmol/L NaCl was selected as the supporting electrolyte. The calibration plots for Tl(Ⅰ) concentration in the range of 2×10^-9—1×10^-7 mol/L were obtained. The detection limit was 5×10^-10 mol/L. For the solutions of 4.0×10^-9 mol/L thallium added before the urine sample pretreatment procedure, the average recovery was 105.6% with a relative standard deviation(RSD) of 15.5%.

²H NMR Spectroscopic Investigation of para-Nitroazobenzene Liquid Crystals

LI Min, LUCKHURST Geoffrey R., TIMIMI Bakir A., QIU Hong-Jin, CHEN Xin-fang

2001, 17(1):  108-114. 

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The orientational order of two liquid crystals , namely, 6-［4-(4-nitrophenylazo)phenyloxy］ hexyl diethanolamines(C6) and 10-1-bromo［4-(nitrophenylazo)phenyloxy］ alkane(B10) was studied by means of ²H NMR spectroscopy with hexamethylbenzene-d18 as the probe molecule. The results show that the directors in the smectic A phase of C6 and the nematic phase of B10 could be aligned, which was parallel to the magnetic field. The orientational order parameter of the solute molecules in C6 was about 0.2, while it is only 0.1 in B10, which is expected because the more ordered smectic phase tends to align solute molecules to a high level. Compared to the orientational order parameter of the solute in the SmC phase of 4［3,4,5-tris(4-dodecyloxybenzyloxy)-benzoyloxy］-4-(4′-dodecyloxybenzoyloxy)biphenyl (Ⅰ) (P₂=0.14 ), it is larger in SmA phase of C6. The relatively higher orientational order parameter of the solute in C6 is attributed to the formation of intermolecular H-bonds in the SmA phase of C6.

Letters

Sythesis, Characterization and Catalysis of[η⁵,η¹-C₅H₄-CHPh-PhO]TiCl₂

WANG Jian-hui, MU Ying, PU Wei-ming, ZHANG Yue-tao, YANG Guang-di, LIU Ju-zheng

2001, 17(1):  115-116. 

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Research Notes

Synthesis and Characterization of Heteropoly Coordination Compounds Containing Optical Ligands

MA Hui-yuan, WANG Xiao-guang, ZHOU Bai-bin, ZHOU Hong-li

2001, 17(1):  117-120. 

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Identification of the Flavone in the Flower Bud of Panax Quinquefolium and Its Content Determination in the Different Parts

MENG Xiang-ying, LI Xiang-gao, TIAN Yi-xin, LIU Yin-yan, ZHENG Lian-xiu

2001, 17(1):  121-126. 

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