First-principles Study on the Electronic Structure and Stability of Mo2-xCrxC

This paper deals with the electronic structure and stability of a series of carbides Mo2-xCrxC based on the pseudopotential plane-waves approach of density functional theory and using the generalized gradient approximation(GGA) for the exchange and correlation potential.The calculation results of formation energies demonstrate that the structure Mo2-xCrxC in range of 0≤x≤1.75 is stable under ambient conditions.The formation energies/stabilities of the structures Mo2-xCrxC increase /reduce with enhancing the content of Cr in the structure.Calculated density of state(DOS) show that an increase in the content of Cr dissolving in Mo2-xCrxC crystal cell can lead to the crystal cell volume slightly to shrinkage,TDOS to be elevated at the Fermi level and the peak value of DOS to decrease at the lower energy region from-13.78 to-10.16 eV.Mulliken population analysis explains that the Mo2-xCrxC phase possess the metallic,covalent and ionic bonds.     

Synthesis and Structural Characterization of [Co（Q）2（H2O）2]（Q=8-Hydroxyquinoline Ion）

8-Hydroxyquinoline(HQ) and its derivatives areof the most intensivelyinvestigatedligands in the co-ordination chemistry[1 -3]. They have been used inmetallic ion detection,chromatography and especiallyin organic light-emitting diodes (OLEDS)[4]. Poly-oxometalates compounds have received muchattentionbecause of their potential applications in catalysis ,sorption, magnetism,photochemistry[5 ,6]. We origi-nally intended to gain the organic-inorganic hybridcomplex of HQ and polyoxometalates . …     

Synthesis,Characterization and Formation Mechanism of Friedel’s Salt（FS:3CaO·A12O3·CaCl2·10H2O） by the Reaction of Calcium Chloride with Sodium Aluminate

The synthesis of Friedel’s salt(FS: 3Ca O·A12O3·Ca Cl2·10H2O) by the reaction of calcium chloride with sodium aluminate was investigated. Factors affecting the preparation of Friedel’s salt, such as reaction temperature, initial concentration, titration speed, aging time and molar Ca/Al ratio were studied in detail. XRD, SEM images and particle size distribution show that the reaction temperature, aging time and molar Ca/Al ratio have significant effect on the composition, crystal morphology, and average particle size of the obtained samples. In addition, the initial Ca Cl2 concentration and Na Al O2 titration speed do not significantly influence the morphology and particle size distribution of Friedel’s salt. With the optimization of the operating conditions, the crystals can grow up to a average size of about 28 um, showing flat hexagonal(or pseudohexagonal) crystal morphology. Moreover, two potential mechanisms of Friedel’s salt formation including adsorption mechanism and anion-exchange mechanism were discussed. In the adsorption mechanism, Friedel’s salt forms due to the adsorption of the bulk Cl- ions present in the solution into the interlayers of the principal layers, [Ca2Al(OH-)6·2H2O]+, in order to balance the charge. In the anion-exchange mechanism, the free-chloride ions bind with the AFm(a family of hydrated compounds found in cement) hydrates to form Friedel’s salt by anion-exchange with the ions present in the interlayers of the principal layer, [Ca2Al(OH-)6· 2H2O]+-OH-.     

Diversity of supramolecular architecture of H2 salpn coordination compounds based on its flexibility

Two complexes,[Cu（salpn） ]·NH（ CH₃）₂（ 1） and [Ni（ salpn）·H₂O]（ 2）（ H₂salpn= N,N-bis（ salicylidene）-propane-1,3-diamine） were characterized by IR,element analysis and single crystal X-ray diffraction analysis. Crystal data for complex 1 : monoclinic,P2₁/ C,a = 1.0974 × 10^-7cm,b = 1.4806 × 10^-7cm,c = 1.0315 × 10^-7cm,β = 94.43（ 3） °. The Cu（ II）ion in complex 1 is four coordinated with distorted square planar coordination geometry. The crystal structure of complex 1 consists of [Cu（ salpn） ] coordination complex and a guest molecule NH（ CH₃）₂that can act as both H-bonding donor and acceptor and plays an important role in constructing supramolecular architecture. Crystal structure data for complex 2 : orthorhombic,Pnma,a = 8.6763× 10^-8cm,b = 2.4145 × 10^-7cm,c = 7.5388 × 10^-8cm. The Ni（ II） ion in complex 2 is fivecoordinated with a butterfly coordination geometry. The coordinated water molecule plays a key role in hydrogen-bonded networks.     

一种新型苝衍生物的凝胶行为

采用离子自组装方法,以苝酐的羧酸盐及阳离子表面活性剂二甲基二十八烷基溴化铵（DOAB）为原料,室温下合成一种新型苝衍生物.借用核磁共振仪（NMR）和傅里叶变换红外光谱仪（FTIR）确定目标产物的化学组成和结构.利用透射电镜（TEM）、X射线衍射仪（XRD）、小角X射线散射仪（SAXS）等表征衍生物的凝胶聚集体形貌及排列结构.结果表明：这种苝衍生物能够在芳香环间的π–π相互作用下,通过自组装过程形成有序排列的聚集体,其在甲苯中的凝胶呈现典型的层状结构,苝环之间的π–π相互作用是其形成凝胶的主要驱动力,相互缠结的烷基链与溶剂之间范德华力促使凝胶结构更加稳定.     

二苄化二硫[PhCH2SSCH2Ph]的合成及晶体结构和热性能分析

通过X-射线单晶衍射,确定了化合物[PhCH2SSCH2Ph]的晶体结构。化合物晶体属于单斜晶系,空间群为C2/c,晶胞参数a=1.351 0(3)nm,b=0.825 94(17)nm,c=1.140 8(2)nm,β=99.35(3)°,z=4。通过S S键桥联2个苄基,2个苄基不在同一个平面上,以S S键为中心扭曲几乎90°。热重分析表明该化合物在260℃完全分解。     

晶体结构中罕见的O-H…π堆积作用

Hinokiol是一种在植物中含量较少的二萜类化合物，对一些细菌有非常好的杀灭作用。Hinokiol从糙苏（Phlomis umbrosa Turcz）中首次分离出来，利用红外图谱和核磁图谱确定了其结构，并利用单晶X-衍射技术对其晶体结构和构象进行了分析，发现Hinokiol晶体结构中除存在氢键外还存在一种罕见的O-H…π堆积作用，这里对O-H…π堆积作用的特征进行了简单地描述。     

1-甲基-4,5-二硝基咪唑的晶体结构与热分解特性

以1-甲基咪唑为原料,通过硝化合成了1-甲基-4,5-二硝基咪唑.以乙腈为溶剂培养得到了1-甲基-4,5-二硝基咪唑单晶,用X射线单晶衍射仪测定了晶体结构.结果表明:晶体属斜方晶系,空间群为P na21.晶体学参数为:a=0.841 2(2)nm,b=1.264 6(3)nm,c=0.656 3(1)nm,V=0.698 2(3)nm3,Z=4,Dc=1.637 g.cm-3,μ=0.147mm-1,F(000)=352.用DSC研究了热分解过程,结果表明:1-甲基-4,5-二硝基咪唑的分解由一个吸热和一个放热过程组成,吸热峰由晶体熔融转变引起,放热峰由热分解所致;较高的分解温度表明1-甲基-4,5-二硝基咪唑有较好的热稳定性.     

二叠氮二邻菲咯啉锰(II)配合物[Mn(N3)2(Phen)2]的合成、晶体结构及热性能分析

合成了配合物[Mn(N3)2(Phen)2],并通过X-射线单晶衍射确定了其晶体结构。晶体结构属于三斜晶系,空间群为P1,晶胞参数为:a=0.963 06(19)nm,b=1.342 5(3)nm,c=1.692 9(3)nm;α=87.00(3)°,β=89.00(3)°,γ=86.00(3)°,Z=1。配合物[Mn(N3)2(Phen)2]的每个分子中,锰(II)离子采取六配位的变形八面体几何构型,每个锰原子分别与2个邻菲咯啉的氮原子及2个叠氮基团的氮原子形成配位键。热重分析显示标题化合物有较高的热稳定性。     

真空和大气退火对ITO膜特性的影响

ＩＴＯ膜主要受溅射过程中溅射参数的影响．本文分析和验证真空和大气退火也改善和提高ＩＴＯ的特性，根据我们的实验条件，本文主要研究退火工艺对ＩＴＯ膜的面电阻、可见光透过率、热稳定性及晶向结构等特性的影响．     

叠氮桥联的三苯基膦二铜(I)配合物[Cu_2(N_3)_2(PPh_3)_4]的晶体结构及热性能分析

通过X 射线单晶衍射,确定了[Cu2 (N3 )2 (PPh3 )4 ]的晶体结构。晶体结构属于单斜晶系,空间群为P21 /c, 晶胞参数为:a=2. 348 8(5)nm, b=1 .373 8(3)nm, c=2 0099(4)nm; β=106 42(3)°, Z=4。配合物 [Cu2 (N3 )2 (PPh3 )4 ]的每个分子是由 2个叠氮基团桥联的双核铜分子,铜(I)离子采取四配位的变形四面体几何构型,每个铜原子分别与 2个三苯基膦的磷原子及 2个叠氮基团的氮原子形成配位键。热重分析显示标题化合物有较高的热稳定性。     

层状磷酸铝的合成、表征以及有机胺模板能力计算

以三乙烯四胺为模板剂,在溶剂热条件下合成一种新型层状磷酸铝化合物([C6N4H21][Al3P4O16]).通过单晶结构解析证实:晶体属于单斜晶系,空间群P21/c(No.14)。晶胞参数a=15.839(2),b=18.868(3),c=16.396(4),V=4350.1(14)3,Z=4。AlO4四面体与PO3(O)四面体通过共顶点氧严格交替排列,形成4×6元环网状结构。无机层以AAAA形式堆积,三质子化的有机胺模板剂位于无机层间与无机层上的P O基团形成H键。进一步通过粉末X-射线衍射I、CP、CHN和差热-热重分析该化合物。通过计算主客体(无机层与有机胺模板剂)之间非键相互作用能量,确定有机胺对无机层结构的模板能力。     

驱动蛋白与微管间阳离子-π和π-π的定量分析

驱动蛋白是一种ATP酶,属于一种在真核细胞中发现的马达蛋白类.驱动蛋白通过ATP的水解供能,能够沿着微管正向运动.驱动蛋白与微管之间存在着阳离子-π和π-π弱相互作用.用Gaussian软件对驱动蛋白与微管之间的阳离子-π和π-π的能量进行量子化学定量计算.根据计算的数据结果,对阳离子-π和π-π分别做了在ATP强结合态和ADP弱结合态两种态下的统计分析,并得到强结合态和弱结合态在总体上能量相差8.32kJ/mol,表明驱动蛋白处于ATP结合态时与微管的相互作用确实强于ADP结合态,这个结果与有关的实验事实定性地吻合.