Synthesis,Crystal Structure and Electrochemistry Properties of an Iron(Ⅲ) Complex Based on the 3,5-Pyridinedicarboxylate and Water Ligands

Reaction of 3,5-pyridine-dicarboxylic acid(3,5-PydcH2) with iron salt in hydrothermal condition results in the formation of a three-dimensional self-assembly network formulated as [C14H14Fe2N2O12]n,and it has been structurally characterized by elemental analysis,IR spectra and X-ray diffraction.It crystallizes in the monoclinic system,space group C2/c with a=9.9633(15),b=12.0942(18),c=7.4297(11) and β=105.822o.The units of Fe2(pydc)2·2H2O are linked into a one-dimensional structure via the chelate carboxylate groups from the 3,5-pyridine-dicarboxylate.The interlayer hydrogen bonding interactions result in a three-dimensional supramolecular architecture.In the complex,the Fe(Ⅲ) ion displays a slightly distorted pentagonal bipyramidal geometry with seven coordination numbers.Cyclic-voltammetry measurement reveals the oxidation and reduction processes for the complex are quasi-reversible in nature.     

Synthesis and Crystal Structure of a Copper(Ⅱ) Compound with 4-Hydroxybenzoic Acid and Isonicotinamide:[Cu(4-hba)_2(inta)(H_2O)]·H_2O

A new copper(Ⅱ) compound has been prepared and fully characterized by elemen-tal analysis,IR,TG and single-crystal X-ray diffraction.The compound [Cu(4-hba)2(inta)(H2O)]·H2O (4-hba=4-hydroxybenzoic acid,inta=isonicotinamide) 1 crystallizes in the monoclinic system,space group P21/c with a=7.590(5),b=11.027(5),c=23.761(5),β=102.5740(10)o,V=1974.1(16) 3,Mr=991.84,Z=2,Dc=1.669 g/cm3,F(000)=1020,μ=1.166 mm-1,R=0.0353 and wR=0.0604 for 3166 observed reflections (I 2σ(I)).In compound 1,the copper cation is penta-coordinated with two carboxylate oxygen atoms from two different 4-hba ligands,two oxygen atoms from two coordinated water molecules and one nitrogen atom from inta ligand,showing a slightly distorted square-pyramidal geometry.     

分子动力学模拟方法研究结构水在糖原合成酶激酶-3β中的作用

用分子动力学模拟的方法揭示了结构水分子在糖原合成酶激酶-3β(GSK-3β)中的作用.如果没有结构水,ATP嘌呤环的结合位置将发生偏移以填补结构水留下的空间;ATP结合口袋中的氢键网络将被破坏,保守残基Lys85与ATP的磷酸根侧链只能形成一个保守氢键,无法维持磷酸根转移所需的线性关系;由于失去了氢键网络的稳定作用,Glu97和Lys85会向远离ATP的方向移动,并导致Arg96的侧链发生偏转,使Arg96无法保持与Arg180和Lys205之间正常的相对位置,最终影响GSK-3β与底物的结合.     

乙醇水溶液荧光发射的时域和频域特性研究

针对乙醇水溶液荧光发射的四个特征参量进行了研究,得出了该溶液发射荧光光子的时域和频域特征参量。发射光谱和激发光谱表明乙醇水溶液中含有三个结构不同的发光物质,其发射峰分别位于290 nm,305 nm和330 nm处,与其相对应的最佳吸收峰为265 nm,280 nm和236 nm。荧光强度随溶液中乙醇与水体积混合比的变化规律也证实了三种不同发光结构的存在。在荧光光谱峰值波长处分别监测其荧光强度随时间的衰变过程,将获得的荧光衰减动力学曲线采用指数方法拟合并进行解卷积处理,测试的荧光寿命分别对应8 ns,12 ns,25 ns。结合乙醇水溶液荧光发射的四个特征参量可以看出:乙醇分子和水分子发生团簇作用形成了三个新的分子结构从而可发射具有不同能量的荧光光子。该研究结果能为乙醇水分子的团簇结构研究提供参考。     

三原子分子振转激发态成簇现象理论研究

在只考虑弯曲振动与总角动量的耦合,而冻结伸缩振动的模型下,采用Jacobi多项式作为弯曲振动的基函数,用严格的变分法研究了H~2O分子的振转激发态的成簇现象。本文计算了H~2O分子的振转能级和函数,研究了振动激发态下转动高激发态中出现的成簇态。     

氢键对氧化石墨烯复合结构层间剪切行为影响研究

针对氧化石墨烯层状复合结构性能优化设计要求及其对环境湿度的高敏感性,开展了氧化石墨烯在湿润环境下的层间剪切行为研究.首先,采用连续力学理论,获取不同氧化浓度时氧化石墨烯层状结构层间粘结能、层间氢键相互作用能及剪切应力表达式;所获得的层间能量理论值与分子动力学模拟结果基本一致.其次,通过在氧化石墨烯层间加入不同含量水分子...     

两个基于羧基-水分子链构筑的超分子镉配合物的合成、晶体结构和荧光性质

以5甲基-3-吡唑甲酸(H₂MPCA)为主配体,在螯合配体菲咯啉(phen)或2,2'-联吡啶(2,2'-bpy)的存在条件下,与醋酸镉在常温下反应得到2个基于氢键构筑的羧基-水分子链的超分子化合物,[Cd(HMPCA)₂(2,2'-bpy)]·2H₂O(1)和[Cd(HMPCA)₂(phen)]·2.5H₂O(2),并通过元素分析、红外光谱、热重分析、X-射线衍射等对其结构进行了表征.结构分析表明,在化合物1和2中,单核镉的配合物和游离水分子通过氢键及π…π堆积作用形成了三维超分子结构,在此过程中,游离水和羧基构筑的链状水分子簇起着非常重要的作用.此外,我们还研究了化合物1和2的热重和荧光性质.     

Molecular Dynamics Simulation of the Structure I Empty Gas Hydrate

The 368 water molecule structure I empty gas hydrates with three possible hydrogen orientations are calculated using TIP4P potential molecular dynamical simulations.The thermodynamic properties and hydrogen bonding are compared with ice Ih.The density of states is analysed based on experimental measurements.The empty gas hydrate at low temperature is stable without gas molecules encaged.