Table of Content

20 March 2001, Volume 37 Issue 2

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The Morphology of Self-assembled Monolayers of Mercapto Methoxy Poly(ethylene glycol) and Its Complex with Poly(acrylic acid)

HOU Shifeng,LI Qiguang,LIU Zhongfan

2001, 37(2):  145-148. 

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The morphology of self-assembled monolayers of mercapto methoxy poly(ethylene glycol) (MPEG) and its complex film with poly(acrylic acid) were investigated with atomic force microscopy. The roughness of the complex film was affected by the concentration and the ionic strength of PAA solution, and some rougher complex film were formed in a solution with high concentration of PAA and stronger ionic strength.

The Method and Related Program to Construct a Localized Active Functional Space in a Large System

DAI Ying,LI Lemin

2001, 37(2):  149-152. 

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A method is proposed to construct a localized active functional space from the density matrix of a large system. The large system is partitioned into central and surrounding areas. The active functional space is mainly localized on the central area. It contains all basis functions centered at the central area and all the orbitals which consist of the basis functions localized in the surrounding area and interact with the basis functions in the central area to a certain extent. An integral number of electrons are involved in the localized active functional space which can be considered as a relatively independent subsystem in the large system and for which formally isolated quantum chemical calculations can be performed. The related program has been coded and is checked through calculating the number of 4f electrons involved in the active functional space centered in the lanthanide atom of lanthanide trichloride and hydrated lanthanide ions.

Study of Interaction of Water-Soluble Fullerene Derivatives with DNA

FANG Pengfei,ZHAO Yuandi,PANG Daiwen,CHEN Yuanyin

2001, 37(2):  153-156. 

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The interaction of ds DNA with a water-soluble C₆₀ derivative was studied using surface electrochemistry of DNA modified electrode and UV-Vis spectroscopy. It was found that the absorbed band of C₆₀ shifted positively in company with the hypochromic effect. Co(phen)₃²⁺ was used as indicator to study the interaction. The results show that this kind of C₆₀ derivative can interact strongly with ds DNA, the bind site is the major groove of helix.

In Situ Electrochemical SPR Study on Electropolymerization Process

KANG Xiaofeng,CHENG Guangjin,DONG Shaojun

2001, 37(2):  157-160. 

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The combination of electrochemistry with surface plasmon resonance (SPR) has been used to in situ investigate the kinetic growth process of polyaniline (PAn) at a gold surface. Sequential oscillations of SPR kinetic curve with a periodicity equal to that of cyclic potential were observed during the film growth. Such a drastic effect is attributed to a larger electronic density at PAn/Au electrode with respect to the bare gold electrode. Evidence from the SPR kinetic curve confirmed that there were three distinct kinetic stages for PAn film growth. In initial fast increase stage, the growth rate of the film was dependant linearly on aniline concentration and the square root of film thickness. A slower kinetic growth was observed in the second stage due to the three dimensional growth and the film degradation. In the third stage, The degradation of PAn film dominates. Different polymerization modes have different growth rate, and thus lead to different structures and properties of the film.

Study on Catalytic Property of Hemin in the Presence of Anion Surfactant

GUO Zhongxian,LI Yuanzong,SHEN Hanxi

2001, 37(2):  161-166. 

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A novel catalytic property of hemin is described. In ammonium buffer medium of pH 8.0～8.9, hemin has an ability to catalyze the decoloration of bromopyro-gallol red. Oxygen dissolved in solution plays a role as an oxidant in the reaction. With sodium dodecylbenzenesulfonate and ethanol as effect-enhancing agents, the catalytic system obeys the Michaelis-Menten equation of enzymatic catalysis. The Michaelis constant, catalytic constant and specificity constant of the system are estimated by Lineweaver-Burk plot to be 3.7×10^-5mol/L, 0.64s^-1 and 1.7×10⁴L·mol^-1·s^-1, respectively. The mechanism of the hemin oxidase-like catalytic system is discussed. Based on this, hemin can be spectrophotometrically determined by equilibrium and kinetic procedures with a linear range and 3σ limit of detection being 2.0×10^-8～6.0×10^-7 and 5.0×10^-9mol/L, respectively.

Determination of Rare Earth Elements in Chloroplasts by Neutron Activation Analysis

ZHANG Zhiyong,WANG Yuqi,LI Fuliang,CHAI Zhifang

2001, 37(2):  173-175. 

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The contents of 8 rare earth elements(REEs)in chloroplasts of Brassia napus were determined by instrumental neutron activation analysis. The results indicated that there were trace amounts of REEs in the chloroplasts, which corresponded to 1 atom of REEs per 2000 chlorophyll molecules. This content was lower than the microelements already known essential for the process of photosynthesis such as Fe, Mn and Cu.

Ionic Conductivity of(PEO)₁₆/LiClO₄ Polymer Electrolyte Plasticized with Ethylene Carbonate(EC)

QIAN Xinming,GU Ningyu,CHENG Zhiliang,YANG Xiurong,DONG Shaojun

2001, 37(2):  182-185. 

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The Polyethylene oxide(PEO)₁₆/LiClO₄ polymer electrolyte plasiticized with EC was studied using Differential Scanning Calorimetry(DSC)and impedance spectroscopy. It is found that the conductivity of the plasticized films were increased and the temperature dependence of the conductivity is Arrhenius-like. Moreover, a schematic of the electrical double layer and an equivalent circuit relative to the SS/polymer-electrolyte/SS structure were proposed.

Combined Wavelet Transform with Neural Network for Oscillographic Chronopotentiometric Determination

ZHENG Jianbin,ZHANG Jun,LIU Hui,ZHONG Hongbo,LI Guanbin,CHEN Liren

2001, 37(2):  167-172. 

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Combination of wavelet transform with function of data compression and neural network is firstly applied to predict quantitatively the concentration of Pb²⁺ and other ions in oscillographic chronopotentiometric determination(OCPD). Compared with RPNN and WNN, combination of the wavelet transform and neural network(CWTNN)for OCPD has higher prediction accuracy and less convergence epoch. This can be explained from two aspects. Firstly, the network operation rate has been greatly enhanced because the optimal detail signal obtained after the wavelet transform not only is the characteristic information in original signal, but also has less number of data points than that of original signal. Secondly, the higher prediction accuracy can be obtained because detail signal used as network input contains lower noise. As a result, the potential application of CWTNN for OCPD and other electroanalytical methods will be very excellent.

Kinetic Studies on Electrochemical Oxidation of Adrenaline to Adrenochrome

ZHANG Zhanjun,LI Jingjian,CAI Shengmin,WU Xizun,ZHANG Wenzhi

2001, 37(2):  176-181. 

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The kinetic characteristics of the electrochemical oxidation of Adrenaline to adrenochrome was studied by UV-Vis Spectroscopy. The measurements showed that the electrooxidation of adrenaline to adrenochrome was typical of the first order reaction and the average apparent rate constant is 1.921×10^-4s^-1.

Studies on Amplified Assay of Surface Plasmon Resonance Immunosensing

PEI Renjun,WANG Erkang,YANG Xiurong

2001, 37(2):  186-191. 

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Surface plasmon resonance(SPR)immunosensor is a relatively new immunoassay technique and has been receiving more and more attention in recent years. However, a major disadvantage of SPR for bioanalytical applications is that low concentration or low molecular mass analytes could not be detected directly. Therefore, it is a challenging task to develop strategies for improving the detection limit/sensitivity of SPR. In this paper, authors present a novel strategy for improving the sensitivity of SPR immunosensing using streptavidin-biotinylated antibody complex. It is proven that the amplification strategy causes a dramatic improvement of the detection sensitivity. This amplification strategy is based on the construction of a molecular complex between streptavidin and biotin labeled protein. The complex can be formed in a crosslinking network of molecules so that the amplification of response signal will be realized due to the big molecular size of complex.

Study on Synthesis and Reactions of Acetyl-substituted Troponoids With Aromatic Aldehyde

GAO Wentao,ZHENG Zhuo,CHEN Huilin

2001, 37(2):  205-209. 

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3-Acetyltropolone 1 reacted with 3, 4, 5-trimethoxybenzaldehyde, 4-hydroxy-3, 5-dimethoxyben-zaldehyde, piperonal and cinnamadehyde to afford respectively 3-(3, 4, 5-trimethoxy)cinnamoyltropolone 2, 3-(4-hydroxy-3, 5-dimethoxy)cinnamoyltropolone 3, 3-(3, 4-methylenedioxy)cinnamoyltropolone 4 and 3-(5-phenyl-2, 4-pentadieneyl)tropolone 5 .2-acetyl-7-methylaminotropolone 6 reacted with 3, 4, 5-trimethoxybenzaldehyde, 4-hydroxy-3, 5-dimethoxybenzaldehyde and 4-hydroxy-3, 4-dibromobenzalde-hyde to give 2-styrylsubstituted-7-methylaminotropolones 7, 8, 9. Compounds 2, 4 reacted with hydroxylamine to give 3-(3, 4, 5-trimethoxy)styryl-8H-cyclohept［d］isoxazol-8-one 10 and 3-(3, 4-methylenedioxy)styryl-8H-cyclohept［d］isoxazol-8-one 11. The reactions of 2, 4 with phenylhydrazine gave 1-phenyl-3-(3, 4, 5-trimethoxy)styryl-1, 8-dihydrocycloheptapyrazol-8-one 12 and 1-phenyl-3-(3, 4-methylenedioxy)styryl-1, 8-dihydrocyclo-heptapyrazol-8-one 13. Compound 1 reacted with 3, 4, 5-trimethoxybenzaldehyde in the presence of ethylorthoformate and perchloric acid to afford 2-(3, 4, 5-trimethoxyphenyl)-4, 9-dihydrocyclohepta ［b］pyran-4, 9-dione 14. The structures of compounds 2～5, 7～14 were confirmed by spectral data and elemental analysis.

Fourier Transform Infrared Spectroscopic Investigation of Human Erythrocytes in Bone Marrow

GAO Tiyu,CI Yunxiang,FU Shuang,WANG Debing

2001, 37(2):  192-196. 

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Eight samples of erythrocytes in bone marrow coming from patients affected by acute myeloid leukemia (AML) and nine samples from patients suffered from chronic myeloid leukemia (CML) were studied by FTIR spectroscopy. Spectroscopic differences of leukemic erythrocytes were observed between AML and CML samples. The ratios of the integrated areas of the band at 1540cm^-1 due to the protein components of erythrocytes, and of the band from 1084cm^-1 mainly involving the vibration of the O-P-O linkages and C-O groups in ribosome, are closer and lower in AML samples than the corresponding ratios in CML samples. The amide Ⅰ band in AML is broader than that in CML. These differences indicate the different contributions of red cells in erythrocytic series in the erythropoietic development from proerythroblast to matured erythrocytes, and the results imply the maturation of red cells in bone marrow are related to the proliferation of leukemic cells. The noticeable differences may have important implications for analyzing and evaluating leukemia.

Partition of Gold (Ⅰ) Cyanide in Polyethylene Glycol Based Aqueous Biphasic Systems

ZHANG Tianxi,LI Wenjun,ZHOU Weijin,GAO Hongcheng,CHEN Jing,WU Jinguang

2001, 37(2):  197-199. 

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The partition of gold (Ⅰ) cyanide in aqueous biphasic systems (PEG/Na₂SO₄)has been investigated. Almost all of gold (Ⅰ) was in the rich-PEG phase. The aqueous biphasic systems have high capability of extraction. The electrical conductivity of rich-PEG phase decreases with the increase of gold (Ⅰ) concentration. FT-Raman spectra show that there is no strong interaction between PEG and gold (Ⅰ) cyanide.

Preparation and Characterization of Nanocrystalline Thin Films of Al₂O₃ or TiO₂ Doped Scandia Stabilized Zirconia Solid Electrolytes

ZHANG Yawen,YANG Yu,JIN Shu,TIAN Shujian,LI Guobao,JIA Jiangtao,LIAO Chunsheng,YAN Chunhua

2001, 37(2):  200-204. 

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Dense,crack-free and uniform nanocrystalline (Al₂O₃)_0.10(Sc₂O₃)_0.08(ZrO₂)_0.82 and (Sc₂O₃)_0.125(TiO₂)_0.175(ZrO₂)_0.70 thin films with thickness of 0.31μm and 0.36μm respectively on Si(100) substrate, have been successfully prepared by a Sol-Gel spin coating method. Cubic nanocrystals can be obtained at relatively low sintering temperature with an average grain size of about 47 nm and 51 nm respectively. The aluminia-doped ScSZ thins film are the same dense as the ScSZ thin films. However, there are a small amount of pinholes found in the microstructure of the titania-doped ScSZ films.

Study on the Surface Location of Reactive Metals of Rh-Mn/SiO₂ Catalyst in Ethanol Synthesis from Syngas

MA Hongtao,WANG Yi,BAO Xinhe

2001, 37(2):  210-214. 

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In this paper, in-situ EPR, TPSR and NMR were used to study the Rh-Mn/SiO₂ catalyst for ethanol synthesis. The results show that the reactive metals Rh and Mn are fixed on the catalyst surface by the interaction with Si-OH, which can enhance the stability of highly dispersed metals. Rh and Mn interact with each other to form the acitve site with high ethanol synthesis activity. The surface Si-OH was found to be of significance on the preparation of catalyst with high catalytic activity.

Comparison of Chemical Processes of Aromatic Amino Acids and a Dipeptide Induced by UV Light and SO₄^·-

SONG Qinhua,XU Yeping,YU Shuqing,MA Xingxiao

2001, 37(2):  215-220. 

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The chemical processes of aromatic amino acids and a dipeptide(Trp-Tyr), which induced by UV radiation and one-electron oxidation of SO₄^·-, were investigated in aqueous solution by KrF(248nm)laser flash photolysis. From optical studies, the photoionization of aromatic amino acids produced radicals and hydrated electron, and the interaction of tyrosine (Tyr) and phenylalanine(Phe)with SO₄^·- radical yields predominantly the corresponding one-electron oxidized radicals. However, with tryptophan(Trp), it is proposed that the SO₄^·- radical interacts predominantly via addition reaction with the indole moiety to produce the C(2)-yl sulphate radical adduct. A intramolecular electron transfer, Trp/N^·-Tyr→Trp-Tyr/O^·, was observed in the process of photoionization of Trp-Tyr by 248nm light, but there was no observation in one-electron oxidation of Trp-Tyr by SO₄^·-.

Characterization and Preparation of Ce-Y-O Solid Solutions and PdO/Ce-Y-O Catalysts for CH₄ Oxidation

LUO Mengfei,SHAN Wenjuan,LI Meijun,LU Jiqing,LI Can

2001, 37(2):  221-225. 

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Ce-Y-O Solid Solution was prepared by citrate sol-gel method, and characterized by using XRD, Raman and TPR techniques. The structure of the solid solution depends on the Ce/(Ce+Y)ratio. When Ce/(Ce+Y)≥0.6, only face centered cubic phase is observed. When Ce/(Ce+Y)≤0.5, only body centered cubic phase is observed. The addition of Y atoms into CeO₂ improves the reduction-oxidation behavior. Ce-Y-O-supported PdO catalysts show higher activity for CH₄ oxidation than PdO/CeO2 and PdO/Y₂O₃ catalysts. The PdO/Ce_0.8Y _0.2O_1.90 catalyst is the most active of all catalysts.

On-line Monitoring of Dissolved Oxygen in Water by a Fiber-optic Chemical Sensor Based on Fluorescence Quenching

LI Wei,CHEN Xi,ZHUANG Zhixia,SUN Dahai,WANG Xiaoru

2001, 37(2):  226-230. 

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A novel circulatory system for on-line monitoring of dissolved oxygen that makes use of a fiber-optic chemical sensor is presented. An oxygen sensitive optode was combined with a membrane onto which was immobilized pyrenebutyric acid as a fluoroprobe, the membrane was composed of cellulose triacetate as a polymer and di-(2-ethyl hexyl)-o-phthalate as a plasticizer. The dissolved oxygen in water was determined via quenching of the fluorescence of pyrenebutyric acid. The optode shows a satisfactory linear response for the dissolved oxygen in water(r=0.9956, n=6). The relative standard deviations were 2.4%～6.1%. The detection limit was 0.03μg/mL(S/N=3). The exposure time and recovery time of the optode membrane are 5s and 25s respectively. The reversibility of the fluorescence signal was evaluated by alternate measurements in air saturated water and nitrogen-purged water. The relative standard deviation(n=6)were found to be 0.7%. The fluorescence intensity of the membrane in contact with flowing water was recorded over a period of 96h. From fluorescence intensity values taken every 4h(n=24)a RSD of 8% was obtained. After 3 month, the fluorescence signal of the membrane had decreased by 14%. The decrease may be due to washing out of fluoroprobe, but this was not an obstacle to its further use; the quantitative information(F₀/F)did not change significantly, where F₀ and F are the fluorescence intensities in the absence and in the presence of oxygen, respectively. The sensor has good reproducibility and long-term stability. The interference was investigated and the selectivity of method in seawater was affirmed by a conventional method.

A Study of Nanocrystalline CdS Prepared in Waterglass Medium

LIU Xiaoheng,LIANG Chunxiang,LI Dan,YANG Xujie,LU Lude,WANG Xin

2001, 37(2):  231-234. 

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At room temperature, Cd(NO₃)₂ solution was dropped in the quickly stirred aqueous solution consisted of Na₂S and waterglass. After the mixture was stirred for 6h, the powders of nanocrystalline CdS were obtained by careful washing and filtering, which were characterized by XRD, TEM and absorption spectrometer. It was found that the average particle diameter(1.4～3.7nm) of CdS powders is controlled by waterglass concentrations, prevailing crystal system whose particles were wrapped by non-crystal CdS belongs to wurtzite phase and the related optical band gap reaches 3.1eV. It was assumed that the non-crystal CdS wrapped on crystal CdS can result in red-shifted luminescence for absorption spectrum.

Electroless Polymerization of Aniline

LIAO Chuanping,SUN Shigang,ZHOU Shaomin,YAO Shibing

2001, 37(2):  235-238. 

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As a new method of polymerization, electroless polymerization was introduced to form polyaniline film on substrate of any shape. In electroless polymerization, aniline molecules were oxidized to form Pn film by soluble oxygen on the catalytic surface of Pt or Pd substrate without the supply of electric current. Similar to the mechanism of electroless plating, electroless polymerization of aniline involves local and spontaneous electrochemical reactions on only substrate.

Quantization of Subgroup, Site Projection Operator and Application to the Fullerenes

LI Anyong

2001, 37(2):  239-243. 

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For a quantized subgroup of the symmetry group of Hamiltonian of a molecule, a site projection operator is defined to produce symmetry-adapted wave functions from the functions with the symmetry of the subgroup. Based on site projection operator, a systematic method is proposed to factorize the single-particle π Hamiltonian into irreducible representations of the maximal symmetry of the molecule. This method has been used to calculate electronic structures of the icosahedral, tetrahedral and dihedral fullerenes and some stability rules are obtained.

Theophylline Recognition Copolymer Membranes Prepared by Molecular Imprinting Method

WANG Hongying,Lü Qiufeng,CAO Shaokui,SUN Hong

2001, 37(2):  244-250. 

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Using molecular imprinting method, the 1, 3-dimethylxanthine(Theophylline, THO)molecular recognition membranes, containing AN segments as membrane formation sites and AA segments as functional sites, were prepared by the phase inversion technique. Here, THO was selected as a template molecule. The hydrogen bonding between AA segments and the THO templates was measured by FT-IR and NMR. The THO templates can be removed from the membrane through washing with acetic acid aqueous solution. The permeation of THO through the membranes is far more than that of 1, 3, 7-trimethylxanthine(Caffeine, CAF), which demonstrated the function of THO molecular recognition of the membrane. The results also show that the increase of the THO templates concentration in the cast solution caused an increase of THO amounts taken into the copolymer membrane.

Studies on the Synthesis and Thermal Stability of Poly(L- lactide)

GE Haixiong,SUI Zhengrong,PAN Xiaochun,CUI Zhaoyun,JIANG Biao

2001, 37(2):  251-254. 

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The synthesis and thermal stability of poly(L-lactide) were investigated. The key factors affecting the polymer intrinsic viscosity were found to be monomer recrystallization times, stannous octoate concentration and polymerization time. The thermal stabilizing agent did not significantly affect the polymer molecular weight. The polymer with a viscosity average molecular weight beyond 200000 was fairly reproducible by optimizing the polymerization conditions. It was found that poly(L-lactide)is thermally unstable above its melting temperature. The thermal stabilizing agent, ULTRANOX 626A, appeared to be able to reduce the extent of the thermal degradation of the polymer.

Study on the Electrochemical Behaviors of Artemisinin(Qinghaosu) and Its Derivatives Ⅱ
Reduction Mechanism of Artemisinin in the Presence of Hemin

CHEN Yang,ZHU Shimin,CHEN Hongyuan

2001, 37(2):  255-260. 

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The interaction between artemisinin and hemin was investigated by electrochemical methods. Artemisinin was irreversibly reduced at -1.08V via a two-electron transfer at the glassy carbon electrode. In the presence of concentration of hemin as low as 4.0×10^-8mol/L, artemisinin can be reduced via the hemin-catalysis and its original cathodic peak at -1.08V completely disappeared. The cathodic overpotential of artemisinin is decreased ca.600mV. This process is verified by the fact that complex EDTA-Fe(Ⅲ) can also promote the artemisinin reduction with decreasing the cathodic overpotential of artemisinin for 590mV. These results show that the reduction of artemisinin at the glassy carbon electrode is a catalytic process with the aids of hemin. Hemin can greatly decrease the cathodic activation energy of the reduction of artemisinin and promote the decomposition of artemisinin.

Synthesis andStructure of the First Three leg Ladder of Coordination Polymer:｛Zn₃(Ac)₄(4, 4′-bpy)₃[N(CN)₂]₂}_n

SUN Baiwang,WANG Zhemin,GAO Song

2001, 37(2):  271-272. 

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The coordination polymer ｛Zn₃(Ac)₄(4, 4′-bpy)₃[N(CN)₂]₂}_n is prepared and characterized by X-ray diffraction. It is an unique threeleg molecular ladder. Crystal data:｛Zn₃(Ac)₄(4, 4′-bpy)₃[N(CN)₂]₂}_n, monoclinic, space group C2/c, a=21.6034(13)，b=11.4566(7)，c=17.7982(12)Å, β=104.245(4)°, V=4269.6(5)ų，Z=4, D_c=1.607Mg/m³，μ=1.741cm^-1, R1=0.0506 and wR2=0.0877. Zn(Ⅱ)atoms are located at the crosspoint of the “rungs” and “rails”. Each ZnⅡ atom located at the side rails has a trigonal bipyramid environment. The ZnⅡ(2) atom located at the crosspoint of the ladder displays octahedral coordination.

Distribution of Lipids in the Core Sediments of the Bohai

WU Ying,ZHANG Jing,YU Zhigang

2001, 37(2):  273-277. 

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Core sediments in the Bohai have been analyzed to assess the sources and diagenesis of organic matter. Two sampling sites have been chosen: E3 and E5, which are located in the center of Bohai Bay. It is indicated that the most important organic source is the terrestrial matter transported by the Yellow River into the Bohai by analyzing the distribution of n-alkanes. The variation of H/L ration along the core could reflect the change of the Yellow River in the history. The observation of the reduced CPI value may suggest the dryness and dams over the Yellow River in these days. With the ratio of BrC_15∶0/nC_15∶0 and nC_18∶1/nC_18∶0 of fatty acids, it is elucidated that fatty acids could be easily degraded in the anoxic than the oxide environment.

Study on the Subcellular Distribution of Sm and Yb in Rat Liver Using Enriched Stable Isotope Tracer

LI Fuliang,WANG Yuqi,ZHANG Zhiyong,SUN Jingxin,CHAI Zhifang

2001, 37(2):  278-281. 

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The enriched stable isotope tracer technique combined with Neutron Activation Analysis (NAA) and differential centrifugation was utilized to investigate the subcellular distribution of rare earth elements Sm and Yb in rat liver. ¹⁵²Sm and ¹⁶⁸Yb were selected for experiment as representatives of the light and heavy REEs, respectively. In order to verify the analytical quality, some standard reference materials were used. The distribution in subcellular fractions was similar for Sm and Yb, the highest contents of Sm and Yb were found in mitochondria, while the lowest in nuclei.

Accurate Time dependent Wavepacket Calculation of O(¹D)+HCl Reaction

LIN Shiying,HAN Keli,ZHANG Zenghui

2001, 37(2):  282-285. 

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Accurate 3D time-dependent wavepacket calculation for the O(¹D)+HCl reaction has been carried out employing the BLRS potential energy surface(R Schinke.J Chem Phys, 1980, 80: 5510～5517). The calculated cross section values are close to the quasiclassical trajectory results and the rate constants are in excellent agreement with experimental results.

Isolation and Identification of 2-(1′, 2′, 3′, 4′-Tetrahydroxybutyl)-6-(2″, 3″, 4″-Trihydroxybutyl)-Pyrazine from Panax pseudoginseng var notoginseng

LI Qi,YAN Aixin,YE Yunhua,XING Qiyi

2001, 37(2):  286-288. 

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A water soluble polyhydroxy derivative of 1, 4-diazine has been isolated from Panax pseudoginseng var notoginseng for the first time. Its structure was determined as 2-(1′, 2′, 3′, 4′-tetrahydroxybutyl)-6-(2″, 3″, 4″-trihydroxybuty)-pyrazine by MS, NMR, 1H-1H COSY, 1H-13C COSY, HMBC etc., it was also confirmed by chemical synthesis.

Self-assembly of an Unprecedented Cynao-bridged One-dimensional 4f-3d Complex[Nd(DMF)₄(H₂O)₂Cr(CN)₆]·nH₂O}

KOU Huizhong,GAO Song,SUN Baiwang,MA Baoqing

2001, 37(2):  261-264. 

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A bimetallic complex {[Nd(DMF)₄(H₂O)₂Cr(CN)₆]·H₂O}_n is reported. It was synthesized as yellow crystals by self-assembly of NdBr₃·6H₂O,H₂ salen and (Bu₄N)₃[Cr(CN)₆](molar ratio of 1∶1∶1) in methanol-DMF mixed solution.Single-crystal X-ray diffraction analysis shows that it consists of a cyano-bridged chain structure. The Nd atom is eight-coordinate with a distorted square antiprism geometry. Each Cr(CN)₆ coordinates to two Nd(Ⅲ) ions using two cis cyanide ligands, while each Nd(DMF)₄(H₂O)₂ group connects two Cr(CN)₆ moieties in a cis fashion, giving rise to an unprecedented chain structure. Crystal data:monoclinic, space group P2₁/c, a=13.200(3), b=12.996(3), c=19.211(4)A°, β＝109.93(3)°, V＝3098.4(11)A°³, Z=4, S=1.012, R1=0.0386, wR=0.0751.

A Novel Tetranulcear Iron Complex［Fe₄O₂(O₂CC₂H₅)₇(bipy)₇］PF₆·(H₂O)₂ (bipy=2, 2′-bipyride): Synthesis and Crystal Structure

YAN Bing,CHEN Zhida,WANG Shixi

2001, 37(2):  265-270. 

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A novel tetranuclear iron(Ⅲ) complex［Fe₄O₂(O₂CC₂H₅)₇(bipy)₇］PF₆·(H₂O)₂(bipy=2, 2′-bipyridine) has been synthesized. X-ray crystal structure analysis shows the complex crystallizes in monoclinic system, space group C2/c, unit cell dimensions a=28.59(2)Å, b=13.0629(10)Å, c=17.2698(14)Å, β=123.6080(10)°, V=5234.3(7)ų, D_c=1.559Mg/m³，Z=4. The molecular structure shows that there are two types of coordination environment for Fe(Ⅲ) atoms. One is formed by two N atoms and four O atoms, another by six O atoms, all in distorted octahedron.