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molecular dynamics simulation on glass transition behaviors of 1,2.propanediol ＆ glycerol aqueous solutions

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Molecular dynamics simulation on glass transition behaviors ...

COMPACT COIL OF LACQUER POLYSACCARIDE:FURTHER EVIDENCE

第十届全国计算(机)化学学术会议

作者： Jing Jie~1,Qiao Qing-An~(1*),Mi Yong-Juan~1,Zhang Hong Yu~1,Chen Xin~1 1 School of chemistry & Materials Science,Ludong university,Yantai 2.402.,{2..

＜正＞1,2.Propanediol and glycerol are reagents widely used in low-temperature vitrification. The glass transition temperature（Tg） of vitrification solutions is a critical parameter of fundamental importance for cryopreservation by *** this paper,the glass transition temperatures（Tg） of several aqueous solutions with different concentrations of 1,2.propanediol or glycerol were studied by isothermal-isobaric molecular dynamics simulation（NPT-MD）.The specific volume of 1,2.propanediol aqueous solution（70%,80%,90%,wt%） was obtained in the temperature range of *** addition,the density and radial distribution function of glycerol aqueous solution（70%,80%,90%,wt%） were simulated at the temperature between 60K to *** Tg values of different systems were *** results showed that,for both systems,the Tg value decreased while the content of water *** Tg value of 1,2.propanediol aqueous was lower than the one for glycerol aqueous solution at the same *** is one more hydroxyl group for glycerol molecule which could form a really stronger H-bond network with water molecules in the system so as to lead a higher Tg *** simulated values of Tg were in accordance with the experimental values,which indicated that the selected simulation conditions and force field are favored to such systems.

关键词： 1,2.Propanediol Glycerol Cryoprotectant solution molecular dynamics simulation Glass transition temperature

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Chinese Chemical Letters 1991年第7期2卷 575-576页

作者： Xing Ping QIU Li Na ZHANG YU Min DU Bao Gong QIAN (Department of chemistry,Wuhan {2.,Wuhan 430072.Zai Min LU (Institute of Jilin Chemical Industry Corporation,Jilin 132.2.)

The weight average molecular weights Mw,radii of gyration^(1/2. second virial coefficients A_2.and intrinsic viscosities in 8 solvent [η]_θof five fractionated samples of the chinese lacquer polysaccharide were meas... 详细信息

The weight average molecular weights Mw,radii of gyration2.^(1/2. second virial coefficients A_2.and intrinsic viscosities in 8 solvent [η]_θof five fractionated samples of the chinese lacquer polysaccharide were measured by light scattering and *** is further evidenced that the polysaccharide in aqueous solution exists as a compact coil resulted from highly branched structure.

关键词： COIL CJ FRS COMPACT COIL OF LACQUER POLYSACCARIDE Zhang

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含烯烃配体的过渡金属配合物的研究 Ⅳ.钼和铬的环庚三烯二羰基[乙氧基(芳基)卡宾]配合物的合成和晶体结构

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化学学报 1987年第3期45卷 314-316页

作者：陈家碧雷桂馨邵美成唐有祺中国科学院上海有机化学研究所北京大学物理化学研究所北京大学物理化学研究所上海

不久前,我们报道了丁二烯三羰基铁和异戊二烯三羰基铁与亲核试剂芳基锂在低温下反应,再用Et3OBF4烷基化,可分别获得一族新奇的异构化的丁二烯-和异戊二烯二羰基[乙氧基（芳基）卡宾]铁配合物。我们又发现环辛四烯三羰基铁与芳基锂进行... 详细信息

不久前,我们报道了丁二烯三羰基铁和异戊二烯三羰基铁与亲核试剂芳基锂在低温下反应,再用Et3OBF4烷基化,可分别获得一族新奇的异构化的丁二烯-和异戊二烯二羰基[乙氧基（芳基）卡宾]铁配合物。我们又发现环辛四烯三羰基铁与芳基锂进行类似的反应,也不生成正常的环辛四烯配位的卡宾配合物,而是得到一系列具有新奇结构的环辛四烯二羰基[乙氧基（芳基）卡宾]铁的异构化产物和（或）环辛三烯三羰基芳基铁配合物。这些产物的结构显示了烯烃在金属化合物中的键合方式是复杂多样的,十分令人感兴趣。因此,我们选择了含奇数碳的环状共轭三烯配体的环庚三烯三羰基钼和铬,在类似的条件下与芳基锂进行反应,以研究不同种类的烯烃配体和不同中心金属对反应产物的影响。

关键词：配合物环庚三烯配体芳基取代基晶体结构结晶构造固体结构卡宾烯烃脂肪族不饱和烃乙氧基烷氧基

Enantioselective Alkynylation of Benzaldehyde Catalyzed by New Chiral Lewis Acid Ligand: Zinc-Amide Complex

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合成化学 2004年第Z1期12卷 53-53页

作者： Kang Yong-feng , Wang Rui 1 ?1,2., Liu Lei1, Yan Wen-jin , Xu Zhao-qing , Zhou Yifeng , Chen Chao1, 1 1 1 Tang Ning Xu Jiangke 1 1. Department of Biochemistry & {2. biology, School of Life Sciences, Lanzhou university, Lanzhou, Gansu 730000, china 2. State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, Gansu 730000, china Department of Biochemistry & {2. biology School of Life Sciences Lanzhou University Lanzhou Gansu 730000 China Department of Biochemistry & {2. biology School of Life Sciences Lanzhou University Lanzhou Gansu 730000 China State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical Physics Chinese Academy of Sciences L

The enantioselective alkynylzinc addition to aldehydes is very useful for the synthesis of chiral propargyl alcohols which are important versatile building blocks of many biologically active compounds and natural products1. A series of chiral oxazolidines were conveniently synthesized from amino acids in three steps with good yields. The use of chiral Lewis acid ligand: zinc-amide complex in situ generated from this oxazolidine with alkylzinc as chiral catalysts for the enantioselective alkynylation of benzaldehyde provides a simple, practical and inexpensive method to generate chiral propargyl alcohols with 93% ee. We report the first example of this asymmetric reaction catalyzed by a chiral Lewis acid ligand: zinc-amide complex ligand(scheme 1). A further investigation of the zinc-amide complex ligand is currently underway.

关键词： asymmetric addition, phenylacetylene, oxazolidine, benzaldehyde

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TD-DFT Study on Structure and Electronic Spectrum of 8-hydroxyquinolinato Manganese Complex

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TD-DFT Study on Structure and Electronic Spectrum of 8-hydro...

Mutations in Substrate-binding Site of Protoporphyrinogen Ⅸ Oxidase from the Aerobic Bacterium Bacillus subtilis

中国化学会第五届全国结构化学学术会议

作者： Xia Shu-Wei Yu Liang-Min Fan Yu-Hua Bi Cai-Feng Yang Li-Rong (Key Laboratory of Marine chemistry Theory and Technology,Ministry of Education,Ocean university of {2.,Qingdao 2.6100)

The structure and electronic properties of 8-hydroxyquinolinato manganese(Ⅲ) complex(MnQ,Q=8-hydroxyquinolinato)have been studied theoretically by using density functional theory(DFT).The structure was optimized and the calculation results showed that the Manganese ion was coordinated with one nitrogen atom and one oxygen atom of 8-hydroxyquinolinato *** average bond length of Mn-N is 0.2.72.m and of Mn-O is 0.1887nm,which were consistent with crystallographic *** addition,the molecular structure and electronic structural characteristics of the complex have been *** contribution of Mn(Ⅲ)to the frontier molecular orbits are very high,to HOMO is 2..53% and to LUMO is 68.30%.The electro-absorption spectrum of MnQ3 was calculated by time-dependent density functional theory,the calculated results show that the two strong absorption peaks are at 756.8nm and 532.7nm respectively due to the charge transformation from intra-ligand to manganese(Ⅲ). From bi-molecular system,charge was transported from one complex to the neighbor *** intermolecular interaction affects the frontier molecular orbital energy and its composition obviously.

关键词： 8-hydroxyquinolinato absorption spectrum time-dependent density functional theory

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Mutations in Substrate-binding Site of Protoporphyrinogen Ⅸ...

LCAO-MO-CO ANALYSIS OF ENERGY BANDS IN ONE-DIMENSIONAL CRYSTAL

第五届全国化学生物学学术会议

作者： Lu Sun Zhen Xi~* State Key Laboratory of Elemento-Organic chemistry,Nankai university,Tianjin 300071

＜正＞Protoporphyrinogen Ⅸ oxidase（PPO）（EC 1.***.3.4）catalyses the oxygen-dependent aromatization of protogen（protoporphyrinogen Ⅸ）to proto（protoporphyrin Ⅸ）.It is the last common step of tetrapyrrole biosynthesis for the formation of haems and *** catalyses the six electron oxidation of protogen using a flavin cofactor and molecular oxygen as terminal

关键词： protoporphyrinogen Ⅸ oxidase Bacillus subtilis mutation

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Chinese Science Bulletin 1984年第4期29卷 475-480页

作者：严继民张启元 Institute of chemistry Academia Sinica Beijing

In the study of the various physical and chemical properties of crystals, it is important to calculate the positions and widths of the energy bands and the state density. Many investigators are interested in the one-dimensional crystal since it possesses some particular characteristics. Much progress in both theory and practice has been made in the last few years. In this paper, we have investigated the mutual relations between the atomic orbital (AO), molecular orbital (MO), and crystal orbital (CO) in the one-dimensional crystal, and pointed out the corresponding

关键词： interested orbital bands mutual pointed 二无 positions fairly 一兮 intramolecular

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Comparison of CGRP release from rat lymphocytes and dorsal root ganglia neurons

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Acta Pharmacologica Sinica 1999年第5期 81-81页

作者： XING Li-Yu, HOU Ling-Fei, WANG Xian(Institute of Vascular Medicine, The Third Hospital, beijingMedical university, beijing 100083, china)

Calcitonin gene-related peptide (CGRP), a neuropeptide contained in sensory neuron, has been demonstrated to be synthesized and released by rat lyrnphocytes in our previous *** this study, some release property and mo... 详细信息

关键词： CGRP Comparison of CGRP release from rat lymphocytes and dorsal root ganglia neurons root

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两种亲水性共聚物结构的研究

高分子材料科学与工程 1986年第1期 10-16页

作者：陆学红程行孙以实清华大学化学与化学工程系

本文研究了N-乙烯基吡咯烷酮-甲基丙烯酸甲酯（VP-MMA）和N-乙烯基吡咯烷酮-甲基丙烯酸β羟乙酯（VP-HEMA）两共聚体系本体聚合产物的结构。研究结果表明,这两体系都属于r1《1,r2.1的共聚体系。P[VP-MMA]较P[VP-HEMA]组成的分散性更大... 详细信息

本文研究了N-乙烯基吡咯烷酮-甲基丙烯酸甲酯（VP-MMA）和N-乙烯基吡咯烷酮-甲基丙烯酸β羟乙酯（VP-HEMA）两共聚体系本体聚合产物的结构。研究结果表明,这两体系都属于r1《1,r2.1的共聚体系。P[VP-MMA]较P[VP-HEMA]组成的分散性更大。少量交联剂双甲基丙烯酸乙二醇酯（EGDMA）的存在对共聚物的组成分布基本上没有影响。共聚物的序列分布受组成影响较大。轻度交联的共聚物中混有PVP线型聚合物。当这两种共聚物被溶眼构成水凝胶时,共聚物的结构特征对水凝胶性能产生较大影响。

关键词：共聚物水凝胶序列分布组成分布聚乙二醇二甲基丙烯酸酯 MMA 单体单元亲水性