Fe2C晶体及低指数晶面的结构与稳定性研究

采用自旋极化的密度泛函理论(DFT)对正交与六方的Fe₂C晶体体相与表面性质进行了研究,计算了晶胞的聚合能、磁矩以及低指数晶面的表面能。研究结果表明,两种晶型Fe₂C 的磁性质相似,但正交堆积的Fe₂C比六方堆积的Fe₂C更稳定。正交晶系Fe₂C低指数晶面的稳定性以 (011) > (110) > (100) > (101) > (001) 顺序降低。对一系列碳化程度不同的碳化铁最稳定表面(Fe₂C(011)、Fe₃C(001)和Fe₄C(100))表面能的比较显示,碳化铁表面的相对稳定性与碳化度非线性相关。另外,与面心立方(BCC)铁最稳定表面(110)相比,Fe₂C、Fe₃C及Fe₄C晶体最稳定表面具有较低的表面能,表明铁表面碳化在热力学上是有利的。     

二(1-正丁基茚基)四羰基二钌的合成与晶体结构

由C9H6-n-BuH与Ru3(CO)12在二甲苯中加热回流, 合成了一个新的双核配合物(η5-C9H6-n-Bu)2Ru2(CO)4. 通过元素分析、红外光谱、核磁共振氢谱对其结构进行了表征. 用X射线单晶衍射法测定了(η5-C9H6-n-Bu)2Ru2(CO)4的结构, 结果表明: 晶体属于三斜晶系, Pī空间群, a＝0.8880(5) nm, b＝1.2337(8) nm, c＝1.3235(8) nm, α＝83.054(12)°, β＝76.683(10)°, γ＝77.036(12)°, V＝1.3713(15) nm3, Dc＝1.588 g•cm－3, m＝1.134 mm－1, F(000)＝658, Z＝2, R1＝0.0993, wR2＝0.2459.     

双组分有机低分子凝胶的研究进展

双组分有机低分子凝胶的研究已成为纳米化学新兴研究领域的热点之一, 形成双组分有机低分子凝胶的有机分子具有多种结构, 例如: 巴比妥酸衍生物、氨基酸衍生物、糖类衍生物、金属有机化合物、胆固醇类衍生物和树枝状分子等. 较系统地综述了目前已知的双组分凝胶及其所涉及的有机低分子凝胶因子的主要结构类型, 并展望了双组分有机低分子凝胶的应用前景.     

新型卟啉衍生物的合成、结构表征和电化学性质的研究

以合成的[5-(4-溴苯基)-10,15,20-三苯基卟啉]锌为底物,通Stille偶联的方法合成5-(4’-氨基-4-联苯基)-10,15,20-三苯基卟啉,[5-(4’-氨基-4-联苯基)-10,15,20-三苯基卟啉]锌配合物以及[5- (4’-甲硫基-4-联苯基)-10,15,20-三苯基卟啉]锌配合物。并用Uv,‘H NMR, IR, Ms, Fs等表征确证了该系列配合物的结构,并用循环伏安法对以上部分产物进行了电化学性质的研究.     

Synthesis and Crystal Structure of cis - 1,2- Dicy ano- 1,2- b is（ 2- me thyl- 4-bromo-3-thienyl）ethane

The title compound cis-1,2-dicyano-1,2-bis（2-methyl-4-bromo-3-thienyl）ethane has been synthesized and structurally characterized by X-ray single-crystal diffraction method. Crystal data： triclinic, space group P1^1, Z = 2, C14H8Br2N2S2, Mr = 428.16, a = 6.9410（5）, b = 11.0150（9）, c = 11.1760（8） A, α = 70.3390（10）,β = 76.1860（10）, γ = 79.5490（10）°, V= 776.59（10） A^3, Dc = 1.831 g/cm^3, μ（MoKα） = 5.478 mm^-1, F（000） = 416, R = 0.0487 and wR = 0.1453 for 2456 observed reflections with I 〉 2σ（/）. X-ray analysis reveals that the two thiophene rings are significantly twisted with an average dihedral angle of 57.45°. The molecule adopts a photo-active antiparaUel conformation and the distance between the two reactive C atoms of thiophene rings is 3.465（8）A. These structural elements which exhibit a suitable geometry are extensively explored for photochromic behavior in the crystalline state.     

A Tetranuclear Complex Assembled from N,N＇-Bis（4-（3＇-formyl-5＇-methylsalicyclidene）-iminoethyl）-4-methyl-2,6-bimethyliminophenol

The reaction of 2,6-diformyl-4-methylphenol, ethylenediamine and Cu（Ⅱ） in the proportion of 3：2：2 yields a new tetranuclear copper（Ⅱ） complex, [Cu2L]2（ClO4）2.2H2O（H3L= N,N＇-bis（4-（3＇-formyl-5＇-methylsalicyclidene）iminoethyl）-4-methyl-2,6-bimethyliminophenol）. The complex has been characterized by ES-MS, IR and X-ray diffraction analysis, and its crystal crystallizes in the triclinic system, space group P1 with a = 10.8673（11）, b = 12.0829（12）, c = 14.4834（15） А, α= 111.946（2）, β= 105.828（2）, γ = 99.583（2）°,V= 1618.5（3） А^3, Dc = 1.605 g/cm^3, Z = 2, Mr = 1564.26, F（000） = 800.0,μ（MoKa） = 1.460/mm, S = 1.063, R = 0.0612 and wR = 0.1163 for 6245 observed reflections （I 〉 2σ（I））. The complex is a dimer of dinuclear copper（Ⅱ） acylic enantiomorph subunit [Cu2L]ClO4.H_2O, held together by π…π weak coordination and hydrogen bonding interactions. In addition, the π…π interactions related to phenyl moieties as well as CH=N…π interactions were also found to stabilize the supramolecular architectures in the solid state.     

Synthesis and Structure of a Cerium Coordination Polymer Templated by Double-Keggin-anion

A porous coordination polymer, {[Ce（dpdo）4（H2O）3]（PMo_12O_40）（dpdo）0.5（H2O）4}n 1 （dpdo = 4,4＇-bipyridine-N,N＇-dioxide）, templated by double-Keggin-type polyanions was synthesized and structurally characterized. The crystal structure was determined by single-crystal X- ray diffraction. The crystal is of triclinic, space group P1 with a = 13.368（4）, b = 16.503（4）, c = 18.506（5）А, α = 88.831（5）, β= 82.095（5）, γ = 83.578（5）°,V= 4018.6（18）А^3, Z=2, C45H50N9O56CeMo12P, Mr = 2935.31, Dc = 2.426 g/m^3, μ= 2.491 mm^-1, F（000） = 2816, the final R=0.0603 and wR = 0.1611 for 11977 observed reflections with I 〉 2σ（I）. Compound 1 exhibits a 3D non-interwoven framework with large cavities housing centrosymmetrically related shoulder-by-shoulder double-Keggin anions as guests.     

Structural Characterization of Volatile Components of Rosa Banksiae Ait for Estimation and Prediction of Their Linear Retention Indices and Retention Times

The molecular electronegativity-distance vector （MEDV） was used to describe the molecular structure of volatile components of Rosa banksiae Ait, and QSRR model was built up by use of multiple linear regression （MLR）. Furthermore, in virtue of variable screening by the stepwise multiple regression technique, the QSRR models of 10 and 6 variables and linear retention index （LRI） 10, 7 and 6 varieables were built up by combinating MEDV with the Ultra2 column GC retention time （tR） of 53 volatile components of Rosa Banksiae Air. The multiple correlation coefficients （R） of modeling calculation values of QSRR model were 0.906, 0.906, 0.949, 0.943 and 0.949, respectively. The cross-verification multiple correlation coefficients （RCV） were 0.903, 0.904, 0.867, 0.901 and 0.904, respectively. The results show that the models constructed could provide estimation stability and favorable predictive ability.     

Theoretical Study on the Structural and Electronic Properties of Thiocarbamide Hydrochloride

In the present paper, the electronic band structure, density of states （DOS）, and projected density of states （PDOS） analysis of thiocarbamide hydrochloride are reported. Calculations of the electronic properties have been carried out on the basis of fully self-consistent pseudopotential method using DFT. The results show that near the Fermi level, more prominent densities of states are seen between -8 eV and -6 eV in the valence band mainly due to the Cl-3p, N-2p and S-3p orbitals.     

Hydrothermal Synthesis and Crystal Structure of a New Manganese（Ⅱ） Complex with 2,4-Pyridine-dicarboxylic Acid and 2,2′-Bipyridine Ligands

A new metal-organic complex [Mn2（PDC）2（bipy）2（H2O）2] （H2PDC = 2,4-pyridine-dicarboxylic acid, bipy = 2,2′-bipyridine） 1 has been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectrum, TG and single-crystal X-ray diffraction. The compound crystallizes in triclinic, space group P ^-1 with a = 7.376（3）, b = 9.990（4）, c = 11.950（5） A^°, α= 75.217（5）, β = 78.052（5）, γ = 70.655（5）°, V = 796.0（5）A^°3, C34HE6Mn2N6O10, Mr = 788.49, De = 1.645 g/cm^3,μ（MoKa） = 0.866 mm^-1, F（000） = 235, Z = 1, the final R = 0.0425 and wR = 0.0700 for 1971 observed reflections （I 〉 2σ（I））. In the crystal structure, the manganese atom is six-coordinated by two carboxylate oxygen atoms from two different PDC ligands, one aqua ligand, and three nitrogen atoms from 2,2′-bipy and PDC ligands, giving a distorted octahedral geometry. It exhibits a three-dimensional supramolecular network defined by O-H…O hydrogen-bonding interactions.