Syntheses and Crystal Structures of Complexes [Cu(C14H8N3O4Br)](C4H9NO) and [Ni(C14H9N2O3Br)](C4H9NO)

The title compounds, Cu(L1)(C4H8NHO) and Ni(L2)(C4H8NHO) (H2L1 = 5-bro- mosalicylaldehyde-p-nitrobenzoylhydrazone, H2L2 = 5-bromosalicylaldehyde-p-hydroxybenzo- ylhydrazone), have been obtained and characterized by single-crystal X-ray diffraction. Complex 1 belongs to the triclinic system, space group P1 with a = 8.6960(2), b = 9.957(2), c = 11.878(2) , α = 73.36(3), β = 78.25(3), γ = 82.64(3)o, V = 962.1(3) 3, Mr = 512.81, Z = 2, F(000) = 514, Dc = 1.770 g/cm3, μ(MoKα) = 3.251, R = 0.0337 and wR = 0.0846. Complex 2 is of monoclinic, space group P21/c with a = 13.313(2), b = 8.2096(1), c = 21.890(3) , β = 125.737(3)o, V = 1941.9(4) 3, Mr = 478.97, Z = 4, F(000) = 968, Dc = 1.638 g/cm3, μ(MoKα) = 3.085, R = 0.0356 and wR = 0.0817. The ligands form a satisfactory N2O2 square plane around the metal centers in two compounds. Different patterns of hydrogen bonds are observed owing to the presence of different substituents on aromatic ring of the acylhydrazone Schiff bases. In complex 1, square-planar copper(II) complexes are linked by intermolecular hydrogen bonds leading to zigzag infinite chains. In complex 2, the metal complexes are linked via hydrogen bonds to form corrugated sheets in a staggered fashion; 3D channels along the b axis are constructed through other non-covalent interactions between the neighboring layers.     

配合物Cu(C14H9NO3)(C3H4N2)的合成、晶体结构及性质研究

合成了配合物Cu(C₁₄H₉NO₃)(C₃H₄N₂)[C₁₄H₉NO₃^2- 为N-(2-羧基苯基)-水杨醛亚胺,C₃H₄N₂为咪唑].晶体属正交晶系,空间群Pca2₁,晶胞参数a=0.94453(12)nm,b=1.12278(9)nm,c=2.9123(4)nm,V=3.0885(6)nm³,Mr=370.84,Z=8,最终的偏离因子R=0.036,wR=0.087,GOF=0.975.三齿Schiff碱配体中的二个氧原子、一个氮原子和咪唑的一个氮原子与铜原子配位,形成扭曲的平面正方形结构.通过元素分析,IR,UV,CV和TG表征了配合物的结构.     

Arrhenius parameters for the reactions CH3. + C4H10 → CH4 + C4H9. and C2H5. + C4H10 → C2H6 + C4H9.

Study of n-butane pyrolysis at high temperature in a flow system allows measurement of the sum of the rate constants of the initiation reactions and of the Arrhenius parameters of the reactions Established data for k₁/k₂ allow estimation of k₁ for 951°K and this, with recent thermochemical data, yields the result log k_?1 (l.mole s^?1) = 8.5, in remarkable agreement with a recent measurement [20] but over si×ty times smaller than conventional assumption. The product k₃k₄ (l.²mole^?2s^?2) is found to be associated with the Arrhenius parameters log (A₃A₄) = 21.90 ± 0.6 and (E₃ + E₄) = 38.3 ± 2.7 kcal/mole. These values are much higher than would be e×pected on the basis of low temperature estimates. Independent evaluation gives log A₄ = 10.5 ± 0.4 (l.mole^?1s^?1) and E₄ = 20.1 ± 1.7 kcal/mole, hence log A₃ = 11.4 ± 0.8 (l.mole^?1s^?1) and E₃ = 18.2 ± 3.2 kcal/mole. These values are shown to be entirely consistent with a wide range of results from pyrolytic studies, and it is argued that they further confirm the view that Arrhenius plots for alkyl radical–alkane metathetical reactions are strongly curved, in part due to tunneling and, appreciably, to other as yet unidentified effects. Since there is published evidence that metathetical reactions involving hydrogen atoms show even greater curvature, it is suggested that this may be a characteristic of many metathetical reactions.