Preparation and crystal structure ofexo-2,exo-6-dihydroxy-2,6-dimethyl-9-oxabicyclo[3.3.1]nonane

In a further exploration of the structural factors causing alicyclic diols such asexo-2,exo-6-dihydroxy-2,6-dimethylbicyclo[3.3.1]nonane (1) to adopt the helical tubuland inclusion host structure, the title compound (8) has been synthesized and its crystal structure determined. This 9-oxa analogue of (1) has a totally different structure [C₁₀H₁₈O₃; orthorhombic;P2₁2₁2;a 18.989(4),b 19.064(3),c 14.256(3) Å;Z 20; with finalR 0.065] due to involvement of the ether oxygen atom in the hydrogen bonding network. The structure of the diol (8) approximatesP¯42₁ c symmetry, and 16 of the 20 molecules per cell create a hostlike structure of this symmetry, which consists of tightly bound hydrogen bonded pillars parallel toc. The remaining guestlike molecules occupy inequivalent pseudo ¯4 sites separated byc/2 to form weakly bound columns parallel toc. Hydrogen bonds also occur between the pillars and columns. An ordered structure with sensible intermolecular contacts can be formed inP2₁2₁2₁ with thec axis doubled. A difference betweena andb axial lengths correlates with a difference in occupancies of pseudo-¯4-related sites for the guest-like component of the structure.     

Effect of the complex forming ion on the physicochemical characteristics of solvation of tetraphenylporphine complexes

The enthalpies of dissolution, transfer, and axial coordination for the Cd(II), Co(II), Mn(III), Fe(III), and Cr(III) complexes of tetraphenylporphine, H₂(TPP), in nonpolar (C₆H₆, CCl₄) and electron-donating solvents (DMF, DMSO, Py,c-C₅H₁₀NH) have been determined calorimetrically at 298.15 K. On the basis of thermogravimetrical data for the corresponding crystallosolvates the composition, thermal stability, and energy of intermolecular interaction of the metal-porphine complexes with pyridine have been calculated. Complexing in noncoordinating solvents brings about no radical change in the physicochemical characteristics of axial coordination which depend critically on the electron structure of the complex-forming metal.Translated fromfzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 846–850, May, 1993.     

Verfeinerung der Kristallstruktur von K2O2

Refinement of the Crystal Structure of K₂O₂ The crystal structure of K₂O₂ has been refined using 241 diffractometer data (Cmca; a = 6.733(1), b = 6.996(1), c = 6.474(1) Å; Z = 4; R_w = 0.050). The distance O? O (1.541(6) Å) is significantly larger than that one assumed for alkali metal peroxides, so far.     

交联聚异丁烯酸甲酯型负载树脂的孔结构与分离稀土性能的关系

本文报导异丁烯酸甲酯型负载树脂的交联度、致孔剂组成和含量对负载树脂孔结构的影响.结果指出,良溶剂和劣溶剂按一定比例混合作为致孔剂,可制备不同孔结构的树脂.致孔剂量增加,树脂表观比重减小,而比表面积、孔体积与平均孔径均增加.交联度从10％增加到35%,表观比重和比表面积增加,而孔体积与平均孔径减小.增加致孔剂所含良溶剂的比例,树脂的表观比重、比表面积增加,而孔体积与平均孔径减小.已制备一系列不同孔结构的2-乙己基膦酸单2-乙己基酯(P507)负载树脂,比较了它们分离La、Ce、Pr、Nd的性能.结果表明,适当孔结构的负载树脂用于萃取色层分离稀土元素具有优良的分离性能.     

Ni(II)-糖胺金属配合物的合成、晶体结构及催化PNPP水解的活性研究

根据文献方法合成了金属配合物[Ni(HL)]Cl₂•2H₂O (HL＝1-[(2-氨乙基)氨基]-2-氨基-1,2-二脱氧-D-葡萄糖), 并用重结晶方法得到了适于X射线衍射的Ni(II)配合物的单晶. 通过对其进行元素分析、红外、紫外光谱及X射线衍射分析, 表明其为畸变的八面体构型. 最后研究了配合物对对硝基苯吡啶甲酸酯(PNPP)催化水解活性.     

N-取代苯甲酰基-N'-取代芳基硫脲的合成、晶体结构及生物活性

为了寻找新的高活性农药, 利用工业易得的三氟羧草醚及其中间体为起始原料, 设计合成了9个未见报道的N-取代苯甲酰基-N'-取代芳基硫脲化合物, 结构经IR, ¹H NMR, 元素分析确认. X射线衍射测定了化合物4b的晶体结构, 结果表明: 其分子属于三斜晶系, 空间群P-1, a＝0.51588(19) nm, b＝1.0766(4) nm, c＝2.0596(8) nm, α＝81.113(6)°, β＝89.702(6)°, γ＝78.131(6)°, V＝1.1056(7) nm³, D_c＝1.445 Mg/m³, Z＝2, F(000)＝492, μ＝0.319 mm^－1. 初步生物活性测试结果表明, 部分化合物具有较好的除草活性.     

量化方法研究分子结BEMP和TEMP的电子输运特性

通过结合杂化密度泛函和前线轨道理论与弹性散射格林函数方法研究了BE- MP(benzene-1,4-di-ethynyl-4-mercaptophenyl)和TEMP(thiophene-2,5-di-ethynyl-4- mercaptophenyl)两分子结的输运性质。基于杂化密度泛函方法计算两扩展分子电子结构的基础上,计算了两分子的输运性质．计算结果显示:电流增加来源于电极和分子轨道的共振;电导曲线呈现出平台特征．在此基础上从扩展分子A(Au-BEMP-Au)中间的苯环的旋转而引起电流减小的角度解释了负微分电阻现象．     

Crystal structure of sodium potassium zinc diphosphate NaKZnP2O7

Single crystals of NaKZnP₂O₇ were grown, and their crystal structure was determined by X-ray diffraction (space group P2₁/n, a = 12.585(5) Å, b = 7.277(5) Å, c = 7.428(5) Å, β = 90.00(5)°, Z = 4, 1916 F(hkl), R ₁ = 0.0461). The structure contains a 3D tetrahedral zinc phosphate framework with a system of intersecting channels running along the b and c axes. The sodium and potassium atoms are coordinated to six and seven oxygen atoms, respectively, and reside inside these channels; the potassium cations, which are larger than the sodium cations, are located at channel intersections.     

苯并噻二嗪衍生物电子结构和非线性光学性质的研究

运用量子化学PM3方法，对苯并噻二嗪几种衍生物的几何构型、电子结构和前线分子轨道成分进行了分析，研究了电荷分布规律。同时，基于体系中电子转移的特点，利用有限场FF方法探讨了其非线性光学性质的变化。结果表明，苯并噻二嗪分子具有较好的二阶非线性光学性质，并可能成为一类良好的光学材料。     

Syntheses and Crystal Structures of 4,4‘—Diformyl—diphenoxyethane and 4,4’,4‘’—Triformyl—triphenoxytriethylamine

Two title compounds, 4,4'-diformyl-diphenoxyethane (compound 1, C16H14O4)and 4,4',4'-triformyl-triphenoxytriethylamine (compound 2, C27H27NO6), were synthesized by condensation of 4-hydroxybenzaldehyde with 1,2-dichloroethane and tris2-chloroethylamine, respectively in dimethyl formamide in the presence of anhydrous potassium carbonate. The crystal data are: monoclinic, P21/c, a = 7.571(2), b = 12.608(3), c = 7.357(2) ', = 105.823(6)o, V = 675.7(2)'3, Mr = 270.3, Z = 2, Dc = 1.328 g/cm3, F(000) = 284, (MoK = 0.096 mm-1, R = 0.0537 and wR = 0.2189 for compound 1; and monoclinic, P21/n, a = 11.7162(6), b = 9.0042(6), c = 22.908(2) ', = 99.505(1)°, V = 2383.5(3) '3, Mr = 461.50, Z = 4, Dc = 1.286 g/cm3, F(000)= 976, (MoK = 0.091 mm-1, R = 0.0464 and wR = 0.1462 for compound 2. The molecule of compound 1 dialdehyde is located at the crystallographic inversion center nearby the midpoint of C8-C8A single bond. The three chains in the molecule of compound 2 trialdehyde are of non-crystallographic pseudo-C3 symmetry, and each of them is quite planar.