Modeling Spin Interactions in a Cyclic Trimer and a Cuboidal Co<sub>4</sub>O<sub>4</sub> Core with Co(II) in Tetrahedral and Octahedral Environments
作者:John F. Berry、F. Albert Cotton、Chun Y. Liu、Tongbu Lu、Carlos A. Murillo、Boris S. Tsukerblat、Dino Villagrán、Xiaoping Wang
DOI:10.1021/ja044185b
日期:2005.4.1
The X-ray crystallographic structures, the magnetic susceptibilities from 2 to 300 K, and a theoretical analysis of the magnetism for a triangular and a tetranuclear molecule consisting of linked high-spin cobalt(II) centers are described. The interpretation of the magnetic data for the triangular compound [Co(depa)Cl](3) (depa is the anion of 2,2'-(bis-4-ethylpyridyl)amine), which has tetrahedrally coordinated Co2+ ions, entails isotropic antiferromagnetic exchange interaction and antisymmetric exchange acting within the two low-lying spin doublets. Two strong isotropic ferromagnetic interactions have been modeled in the cuboidal compound Co-4(DPM)(4)(CH3O)(4)(CH3OH)(4) (DPM represents the anion of dipivaloylmethane), which has octahedral coordination, and the system can be approximately considered as two weakly coupled S = 3 species.