神舟七号飞船小卫星伴飞原理分析

神舟七号伴飞小卫星和神舟七号飞船由于两个轨道的近地点和远地点不重合,导致它们在共同绕地球公转的同时,伴飞小卫星也在绕神舟七号飞船做周期性椭圆运动.伴飞周期等于飞船绕地球公转的周期,飞船位于椭圆轨道的几何中心.     

Synthesis,Structure, and Properties of {[Mn(ADA)(Phen)]·(H_2O)_2}_n Constructed from Azobenzene-4,4?-dicarboxylic Acid and 1,10-Phenanthroline

One coordination polymer(CP) {[Mn(ADA)(Phen)](H_2O)_2}_n(1, H_2ADA = azobenzene-4,4?-dicarboxylic acid, Phen = 1,10-phenanthroline), has been synthesized via hydrothermal reactions. CP 1 was characterized by elemental analyses, IR spectra, thermal behaviors, and X-ray single-crystal diffraction. In CP 1, each ADA~(2-) ligand bridges two Mn~(2+) to give one-dimensional zigzag chains with the Mn···Mn separations of 17.6911 and 16.3976 ?, which generates a three-dimensional supramolecular structure by means of strong π···π interaction and hydrogen bonding. It crystallizes in triclinic, space group P1, with a = 7.6200(13), b = 9.1530(15), c = 18.262(2) ?, α = 88.467(3)o, β = 84.145(2)o, γ = 77.542(2)o, V = 1237.2(3) ?~3, Z = 2, C_(26)H_(20)MnN_4O_6, Mr = 539.40, Dc = 1.448 g/cm~3, F(000) = 554, S = 1.018, R = 0.0531 and w R = 0.1094. In addition, natural bond orbital analysis was performed by the B3 LYP/LANL2 DZ method of Gaussian 09 Program. The fluorescence, magnetic, and electrochemical properties of 1 have been investigated.     

Boron Group Ions Direct Conversion of Carbon and Methane into Ethylene in DFT Study

In this study, density functional theory calculations reveal how boron group ions M^+(M = B, Al, Ga, In, and Tl) directly convert carbon and methane into ethylene at room temperature. M^+ reacts with the carbon atom to form the cation MC^+. Then, the reaction of MC^+ with methane leads to the cleavage of metal-carbon bond and the formation of CH2CH2 through C-C coupling, with the ion M^+ serving as a leaving group. The cycle then begins again. The mechanism of C/CH4 system catalyzed by five ion types is investigated herein, and the reasons for the different reactivity of five ion types are determined. The moderate strength of the Al^+-C bond results in Al^+ being the only appropriate catalyst of M^+(M?=?B, Al, Ga, In, and Tl) that can catalyze methane and carbon into ethylene.     

单环共轭多烯的结构与芳香性研究

基于先进的量化计算软件Gaussian和波函数分析软件Multiwfn,研究结构化学课程中七种单环共轭多烯和环碳18的结构,形成“有图有真相”的立体直观的分子空间结构,形象化展示了各个分子的几何结构、分子尺寸、静电势、芳香性等。将课本知识与先进的量化软件结合起来,在量子化学层次上拓展有关芳香性的认识,引导学生加深对课本知识的理解,同时开拓学生的视野和知识层次。     

基于三羧酸异构体的二维锌配位聚合物对硝基苯的荧光传感

在水热条件下,以2个异构体5-((3-羧基苯氧基)亚甲基)间苯二甲酸(3-H₃CIA)、5-((4-羧基苯氧基)亚甲基)间苯二甲酸(4-H₃CIA)和3-双(咪唑-1-甲基)苯(3-bibz)为原料,合成了2种二维锌(Ⅱ)配位聚合物(CPs)：[Zn₄(3-CIA)₂(OH)₂(3-bibz)₂](1)和[Zn₂(4-CIA)(OH)(3-bibz)]·H₂O (2),采用单晶X射线衍射、红外光谱、热重、粉末X射线衍射技术进行了表征。结构分析表明,由于2个异构体的配位方式不同,CP 1为基于四核单元的二维网结构,而2则为基于三核单元的二维网络结构。CP 1和2对有机溶剂的荧光传感测试表明,其荧光对水中的硝基苯都表现为完全猝灭现象,检出限分别为0.248和0.309 μmol·L^-1。理论计算表明,1和2对硝基苯传感机理主要可归因于光诱导电子转移(PET)效应。