Hydrothermal Synthesis,Crystal Structure and Fluorescence Spectrum Studies of a Supramolecular Compound {[2-(2-Pyridyl)benzimidazoleH_2]~(2 )·[SbCl_5]~(2-)}_2

A new supramolecular compound,{[2-(2-pyridyl)benzimidazoleH2]2 ·[SbCl5]2-}2,was synthesized by the hydrothermal reaction of o-diaminobenzene,2-pyridinecarboxylic acid and SbCl3 in 1:1 HCl solution,and characterized by chemical analysis,elemental analysis,IR spectra,thermogravimetric analysis and fluorescence spectra. The crystal structure was deter-mined by X-ray single-crystal diffraction. The crystal belongs to the monoclinic system,space group P21/c,with a=16.0397(13),b=14.3189(12),c=15.6370(13),β=105.8980(10)°,V=3454.0(5)3,Z=4,C24H22Cl10N6Sb2,Mr=992.48,Dc=1.909 g/cm3,μ=2.366 mm-1,S=1.010,F(000)=1920,R=0.0254 and wR=0.0555. The coordination anion,[SbCl5]2-which is a distorted tetragonal pyramid,is composed by coordinating action with Sb3 ion and five adjacent chloride ions. Every four coordination anions of [SbCl5]2-form a biquaternion ring structure through the secondary bonding of Sb···Cl. Moreover,the compound adopts a three-dimensional network supramolecular structure because of the hydrogen bonds and π-π stacking between the rings and the 2-(2-pyridyl)benzimidazole divalent cations. The title compound also shows good fluorescent behaviors.     

铜铁甘草酸配合物的合成及其抗氧化活性研究

甘草酸(G lycyrrhizic acid)又名甘草皂甙和甘草甜素,是从豆科植物甘草和光甘草的根茎中提取的一种三萜皂甙,是常见中药甘草的主要成分。分子结构如图1所示,其分子中含有的羧基和酮基易与金属离子作用形成配合物[1-5]。图1甘草酸的结构图F ig·1 The structure patterns of gly     

大环碳酸酯的Novozym-435酶促开环聚合

研究了14元环的碳酸丁二酯二聚体在固定化脂肪酶Novozym-435催化下的开环聚合反应制备聚碳酸丁二酯.聚合在常压,75℃的甲苯溶液中进行,反应条件温和.详细探讨了反应条件诸如单体浓度,酶浓度对于聚合的影响.结果显示Novozym-435具有与异辛酸亚锡可比拟的高催化活性,同时可以回收重复使用.聚合动力学研究表明碳酸丁二酯的酶促甲苯溶液开环聚合和环状内酯的酶促甲苯溶液聚合有所不同,没有表现出活性聚合的特征.     

TiO2-活性白土复合光催化剂的合成与活性研究

采用溶胶法合成了TiO₂-活性白土复合光催化剂,借助XRD、XPS、SEM和UV-Vis等技术对其进行了表征,并以甲基橙为模型污染物考察了合成工艺对其光催化活性的影响规律。物相结构、扫描电镜和比表面积测试结果表明,部分纳米TiO₂粒子插入活性白土层间,使其层间距扩大,复合光催化剂因而具有较高的比表面积;紫外-可见吸收光谱分析表明,与纯纳米TiO₂相比,复合光催化剂在其吸收带内具有更强的吸收,且吸收边发生红移;光催化实验表明,当TiO₂理论负载量为66%、煅烧温度为400 ℃时,所得复合光催化剂对甲基橙的脱色及卷烟厂蒸叶废水的处理均具有较高的催化活性。     

Swelling Properties and Environmental Responsiveness of Superabsorbent Composite Based on Starch-G-Poly Acrylic Acid/Organo-Zeolite

Star-g-poly (acrylic acid)/organo-zeolite 4A (S-g-PAA/OZ) superabsorbent composite was prepared by grafting partially neutralized acrylic acid onto starch in the presence of organo-zeolite 4A (OZ) as an inorganic component. The morphology was characterized with scanning electron microscopy (SEM). Energy dispersive spectrometer (EDS) analysis revealed the fine distribution of OZ in superabsorbent composite. The swelling kinetics of the composites were characterized by means of a Schott's second-order model. The effect of OZ concentration in the composite on the water absorbency and swelling behavior were tested. The swelling properties of the composites were evaluated in various environments; pH, salinity, temperature, urea solution, and solvent-water mixtures. The activation energy (ΔE) for water during the swelling process was also determined through Arrhenius plots. The results showed that the proper amount of OZ was beneficial for improvement of the water absorbent capacity and the initial swelling rate in distilled water. The optimum prepared composite with 10 wt % OZ, possessed the maximum water absorption (511g/g) in distilled water and (521 g/g) in 0.1 wt % urea solution. The results inferred that S-g-PAA/OZ superabsorbent composite can be exploited for agriculture and medical applications.     

Convenient synthesis of highly functionalized pyrazolines via mild, photoactivated 1,3-dipolar cycloaddition

A mild, photoactivated 1,3-dipolar cycloaddition procedure was successfully developed for the synthesis of polysubstituted pyrazolines. This procedure involved the in situ generation of the reactive nitrile imine dipoles using a hand-held UV lamp at 302 nm, followed by spontaneous cycloaddition with a broad range of 1,3-dipolarophiles with excellent solvent compatibility, functional group tolerance, regioselectivity, and yield.     

The Contribution of the Fourth Order Exchange Diagrams to The Relativistic Microscopic Optical Potential

The contribution of the fourth order exchange diagrams is first studied to the imaginary part of nucleon self-energy,the relativistic microscopic optical potential and the Schrodinger equivalent potential of the relativistic microscopic optical potential based on Walecka's meson-nucleon model.     

Statistical Fluctuation of Linear-System Driven by Colored Noise

The Brownian motion driven by colored noise in the harmonic oscillator potential is studied, and the "best Fokker-Planck equationn" is proposed. The analytical formulse of the second moments of coordinate and velocity are obtained. The fluctuation behavior of a system under influence of the correlation time of colored noise is discussed.     

Second Order Correction of Relativistic Optical Potential

The imaginary part of the off-energy shell optical potential of a nucleon in nuclear matter, where the polarization and correlation contribution of the exchanges of the σ and ω mesons are taken into account, is derived in the framework of the relativistic meson-nucleon field theory. The second order correction of the real part of the optical potential is calculated in terms of the dispersion relation and the effective mass of a nucleon in the nuclear medium is also investigated in this paper.