夹心型杂多化合物Na_9[CeW_(10)O_(36)]·34H_2O的合成及晶体结构

在pH≈6.5及NaAsO_2和Co(NO_3)_3·6H_2O存在下,Na_2WO_4·2H_2O 与Ce (NO_3)_3·6H_2O反应,得到了Na_9[CeW_(10)-O_(36)]·34H_2单晶。用元素分析 及X射线单晶衍射法确定了其组成与结构,晶体学数据为：a = 1.3010(5) nm, b = 1.3072(5) nm, c = 1.9962(8) nm, α= 101.073(7) °, β = 104.411(5) ° γ = 90.473(4) °, V = 3.221(2) nm~3,空间群P1,V=3.211(2)nm~3, Z = 4, 最终R因子[1>2σ(I)]R_1=0.0424, wR_2 = 0.0549, R因子（全部数据）R_1=0. 1357, wR_2 = 0.0808.[CeW_(10)O(36)]~(9-)具有D_(4d)对称性。     

常温常压下五元杂环的催化加氢反应

 考察了常温常压下吡咯、呋喃和噻吩的催化加氢反应;用紫外吸收光谱、气相色谱和酸碱度测定分析了反应物质;用比表面积测定、X射线衍射、透射电镜及高分辨电镜表征了催化剂．结果表明,在纳米量级的镍基催化剂作用下,双键五元杂环的加氢反应过程是多反应同时进行：主要有环上双键先加氢生成四氢化物单键环,继而开环加氢生成若干小分子气体;也有直接开环反应．总体上是在还原条件下实现降解反应．超声波的介入有利于保持催化剂的活性．对反应机理进行了探讨．     

Non-covalent Interactions in the Crystal Lattices of Copper(II) Complexes with Macrocyclic Ligands Containing Aryl Substituents

It has been established that, depending on the structure of the substituents in the ligand, macrocyclic complexes of copper(II) show in the crystal lattice different types of non-covalent interactions (hydrophobic, CH- interactions, and -stacking) which lead to the formation of intermolecular aggregates (dimers) and the formation of layer structures with alternating hydrophobic and hydrophilic regions.     

The further crystallographic refinement of trichosanthin at 2.7A resolution and the comparison among the three molecular structures in two crystal forms

The three-dimensional structure of trichosanthin at 2.7A resolution has been improved further, by refitting one of the C-terminal tails, adjusting 16 residues in the molecular surface regions, discarding some water molecules with high B values, and adjusting weights during the further refinement. The R-factor has been reduced to 18.5% and the r.m.s deviations from ideal geometry are also improved. The structures of the two molecules in the monoclinic asymmetric unit and the only molecule in the orthorhombic asymmetric unit are compared with one another. The main-chain structures for most of the residues in the three molecules are substantially the same. However, the courses of the three C-terminal tails are completely different, and the intermolecular interactions resulting from the particular packing of the molecules in the crystals account for the differences. The strand Be-2 and the preceding B-turn in small domain show large r.m.s. deviations among the three molecules and they are also involved in i     

Representing the automorphism group of an almost crystallographic group

Let be an almost crystallographic (AC-) group, corresponding to the simply connected, connected, nilpotent Lie group and with holonomy group . If , there is a faithful representation . In case is crystallographic, this condition is known to be equivalent to or . We will show (Example 2.2) that, for AC-groups , this is no longer valid and should be adapted. A generalised equivalent algebraic (and easier to verify) condition is presented (Theorem 2.3). Corresponding to an AC-group and by factoring out subsequent centers we construct a series of AC-groups, which becomes constant after a finite number of terms. Under suitable conditions, this opens a way to represent faithfully in (Theorem 4.1). We show how this can be used to calculate . This is of importance, especially, when is almost Bieberbach and, hence, is known to have an interesting geometric meaning.

     

Synthesis, Characterization and Crystal Structure of an Inorganic-organic Composite Metatungstate: [Co(4,4''-bipy)2(H2O)4](4,4''-H2bipy)2[H2W12O40]·5.5H2O

A novel hybrid compound [Co(4,4'-bipy)2(H2O)4](4,4'- H2bipy)2[H2W12O40]·5.5H2Ohas been synthesized from an acidified aqueous solution and characterized by elemental and thermal analyses, IR and UV spectroscopy, and single-crystal X-ray structure determination. Structure analysis indicates that the title compound is of monoclinic, space group C2/c, with a = 21.315(9), b = 15.303 (7), c = 24.139(10) (A), β = 105.170(5)o, V = 7599(6) (A)3, Mr = 3706.99, Z = 4, F(000) = 6616, Dc = 3.231, μ = 18.395 mm-1, R = 0.0652 and wR = 0.1594. X-ray crystallographic study shows that the title compound consists of one [Co(4,4'-bipy)2(H2O)4]2 cation, two diprotonated 4,4'-bipyridine molecules, 5.5 water molecules of crystallization, and one metatungstate polyoxoanion [H2W12O40]6-, which approaches an effective Td point symmetry. TG-DTA analysis indicates that the framework of the metatungstate polyoxoanion is collapsed at 587.0 ℃.     

4,4-Dialkyl-substituted N-Methylmorpholinium 3,5-Dicyano-6-oxo-1,4,5,6-tetrahydropyridine-2-thiolates and Some of Their Properties

4,4-Dialkyl-substituted N-methylmorpholinium 3,5-dicyano-6-oxo-1,4,5,6-tetrahydropyridine-2-thiolates were synthesized by the condensation of 2-alkyl-2-cyanoethyl crotonates with cyanothioacetamide and N-methylmorpholine. They were used for the production of substituted 2-alkylthio-1,4,5,6-tetrahydropyridines, 2-acetylthio-1,4,5,6,-tetrahydropyridine, 6-hydrazino-1,4,5,6-tetrahydropyridine, and 2,3,4,5,6,7-hexahydrothiazolo[3,2-a]pyridine. The structure of 6-bromo-3-bromomethyl-6,8-dicyano-7,7-dimethyl-2,3,4,5,6,7-hexahydrothiazolo[3,2-a]pyridine was proved by X-ray crystallographic analysis.     

Synthesis and Crystal Structure of Spiro[1-bromo-4-l-menthyloxy-5-oxo-6-oxa-bicyclo[3.1.0]hexane-2,2'-3'-(16'-methoxyacetatyl-4'-l-menthyloxybutyrolactone)]

The title compound,spiro[1-bromo-4-l-menthyloxy-5-oxo-6-oxa-bicyclo[3.1.0]-hexane-2,2'-3'-(16'-methoxyacetatyl-4'-l-menthyloxybutyrolactone)] 1,was obtained via tandem asymmetric double Michael addition/internal nucleophilic substitution of the chiral synthon,5-l-menthyloxy-3-bromo-2-(5H)-furanone 2 with methoxy α-chloroacetate as a nucleophile under mild conditions,and structurally determined by single-crystal X-ray diffraction.Crystal data:C31H47BrO9,Mr = 643.60,orthorhombic,space group P212121,a = 9.6564(7),b = 14.8994(11),c =23.6771(17) (A),V= 3406.5(4) (A)3,Z= 4,Dc= 1.255 g/cm3,λ(MoKα) = 0.71073(A),μ= 1.254 mm-1and F(000) = 1360.The structure was refined to R =0.0324 and wR = 0.0737 for 5123 observed reflections (I ＞ 2σ(I)).The crystallographic results of molecule 1 show that the interesting reaction of 2 with methoxy α-chloroacetate,in the usual manner,gave the spiro-cyclopropane skeleton with O-linked derivative containing multiple stereogenic centers 1 rather than the expected C-linked derivative.     

Microstructure and magnetic properties of FeRh thin films with Pt doping

In this paper,the structure and magnetic properties of FeRh alloy thin films with a small amount of Pt doping fabricated onto a glass substrate by sputtering are investigated systematically.XRD results show that the diffraction pattern of as-deposited film exhibits only nonmagnetic γ phase.After annealing,the disordered γ phase transforms to an ordered α' phase.The temperature dependence of saturation magnetization of different annealing times and Pt contents are characterized.The phase transition temperatu...     

Out-of-plane deformation of the azulene ring in crystal structures of simply substituted azulene derivatives

The crystal structures of 1,3-bis(4-bromophenyl)- and 1,3-di(2-thienyl)azulenes (5 and 6) were elucidated by X-ray analysis. Two aryl groups connect to the azulenyl core with dihedral angles of 34.9-41.6° and the two aryl planes of the groups slant against the azulene ring toward different ways in their crystal structures. It was also found that the azulene rings of 5 and 6 showed a slight out-of-plane deformation in the way that the hydrogen atoms at the 4- and 8-positions are apart from the neighboring aryl ortho-hydrogen atoms to fill in the vacant space made by the slanting aryl planes.