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
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- 作者：Joachim Bebendorf ; Hans-Beat Bü ; rgi ; Eduard Gamp ; Michael A. Hitchman ; Angela Murphy ; Dirk Reinen ; Mark J. Riley ; and Horst Stratemeier
- 刊名：Inorganic Chemistry
- 出版年：1996
- 出版时间：December 4, 1996
- 年：1996
- 卷：35
- 期：25
- 页码：7419 - 7429
- 全文大小：272K
- 年卷期：v.35,no.25(December 4, 1996)
- ISSN：1520-510X
文摘
The crystal structure ofbis(1,3,5-trihydroxycyclohexane)copper(II) tosylate isreported at temperatures of 293,233, 188, 163, and 93 K, as are the structures of the Zn(II) andNi(II) analogues at room temperature for comparison.The isomorphous compounds are triclinic, space groupP
, with one formula unit in the unit cell. Theunit cellparameters of the Cu compound at 293 K are a =6.456(5) Å, b = 9.505(3) Å, c =12.544(3) Å, 
= 76.57(2)
,
= 87.48(4), 
= 76.65(4). Thecentrosymmetric ZnO6 and NiO6 octahedra aretetragonally compressed witha slight orthorhombic distortion. The Cu2+ polyhedraexhibit similar geometries, but with considerably largerdeviations from a regular octahedron. Two of the three independentCu-O bond lengths and two of the g-valueschange significantly as a function of temperature. A model ofdynamic vibronic coupling is presented whichexplains both the EPR and structural data. Vibronic wave functionsassociated with a Jahn-Teller potentialenergy surface modified by an orthorhombic lattice "strain" aregiven. The temperature dependence of the structuresis calculated from the nuclear parts and that of theg-values from the electronic parts of the wave functions.Thetemperature dependence of the structures and g-values isalso interpreted using a simpler model involving anequilibrium between two forms of the complex which differ solely intheir orientation in the crystal lattice, andthe results of the two approaches are compared.
, with one formula unit in the unit cell. Theunit cellparameters of the Cu compound at 293 K are a =6.456(5) Å, b = 9.505(3) Å, c =12.544(3) Å, = 76.57(2), = 87.48(4), = 76.65(4). Thecentrosymmetric ZnO6 and NiO6 octahedra aretetragonally compressed witha slight orthorhombic distortion. The Cu2+ polyhedraexhibit similar geometries, but with considerably largerdeviations from a regular octahedron. Two of the three independentCu-O bond lengths and two of the g-valueschange significantly as a function of temperature. A model ofdynamic vibronic coupling is presented whichexplains both the EPR and structural data. Vibronic wave functionsassociated with a Jahn-Teller potentialenergy surface modified by an orthorhombic lattice "strain" aregiven. The temperature dependence of the structuresis calculated from the nuclear parts and that of theg-values from the electronic parts of the wave functions.Thetemperature dependence of the structures and g-values isalso interpreted using a simpler model involving anequilibrium between two forms of the complex which differ solely intheir orientation in the crystal lattice, andthe results of the two approaches are compared.