Temperature Dependence of the Crystal Structure and EPR Spectrum of Bis(1,3,5-Trihydroxycyclohexane)copper(II) Tosylate. A Unified Interpretation Using a Model of Dynamic Vibronic Coupling.
Temperature Dependence of the Crystal Structure and EPR Spectrum of Bis(1,3,5-Trihydroxycyclohexane)copper(II) Tosylate. A Unified Interpretation Using a Model of Dynamic Vibronic Coupling.
复制标题
双(1,3,5-三羟基环己烷)甲苯磺酸铜(II)的晶体结构和 EPR 谱的温度依赖性。
DOI：
10.1021/ic960343r
复制
发表时间：
1996
影响因子：
4.6
通讯作者：
H. Stratemeier
中科院分区：
文献类型：
--
作者：
J. Bebendorf;H. Bürgi;E. Gamp;M. A. Hitchman;A. Murphy;D. Reinen;M. Riley;H. Stratemeier
在293、233、188、163和93 K的温度下报道了双（1，3，5-三羟基环己烷）甲苯磺酸铜（II）的晶体结构，作为比较，在室温下Zn（II）和Ni（II）类似物的结构也是如此。同晶化合物是三斜晶系，空间群P，在晶胞中有一个分子式单元。在293 K时，Cu化合物的晶胞参数为a = 6.456（5）°，B = 9.505（3）°，c = 12.544（3）°，α = 76.57（2）°，β = 87.48（4）°，γ = 76.65（4）°。中心对称的ZnO（6）和NiO（6）八面体被四方压缩，并伴有轻微的正交畸变。Cu（2+）多面体表现出类似的几何形状，但与正八面体有相当大的偏差。三个独立的Cu-O键长和两个g值的变化显着作为温度的函数。提出了一个动态振动耦合模型，它解释了EPR和结构数据。本文给出了用斜方晶格“应变”修正的Jahn-Teller势能面的振动波函数。的结构的温度依赖性计算从核部分和g值的电子部分的波函数。的结构和g值的温度依赖性也解释使用一个更简单的模型，涉及两种形式的复杂的不同的只是在他们的取向在晶格之间的平衡，和两种方法的结果进行了比较。
The crystal structure of bis(1,3,5-trihydroxycyclohexane)copper(II) tosylate is reported at temperatures of 293, 233, 188, 163, and 93 K, as are the structures of the Zn(II) and Ni(II) analogues at room temperature for comparison. The isomorphous compounds are triclinic, space group P&onemacr;, with one formula unit in the unit cell. The unit cell parameters of the Cu compound at 293 K are a = 6.456(5) Å, b = 9.505(3) Å, c = 12.544(3) Å, alpha = 76.57(2) degrees, beta = 87.48(4) degrees, gamma = 76.65(4) degrees. The centrosymmetric ZnO(6) and NiO(6) octahedra are tetragonally compressed with a slight orthorhombic distortion. The Cu(2+) polyhedra exhibit similar geometries, but with considerably larger deviations from a regular octahedron. Two of the three independent Cu-O bond lengths and two of the g-values change significantly as a function of temperature. A model of dynamic vibronic coupling is presented which explains both the EPR and structural data. Vibronic wave functions associated with a Jahn-Teller potential energy surface modified by an orthorhombic lattice "strain" are given. The temperature dependence of the structures is calculated from the nuclear parts and that of the g-values from the electronic parts of the wave functions. The temperature dependence of the structures and g-values is also interpreted using a simpler model involving an equilibrium between two forms of the complex which differ solely in their orientation in the crystal lattice, and the results of the two approaches are compared.