Ligand Effects on the Ferro- to Antiferromagnetic Exchange Ratio in Bis(o-Semiquinonato)copper(II)
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- 作者：Victor I. Ovcharenko ; Elena V. Gorelik ; Sergey V. Fokin ; Galina V. Romanenko ; Vladimir N. Ikorskii ; Anna V. Krashilina ; Vladimir K. Cherkasov ; Gleb A. Abakumov
- 刊名：Journal of the American Chemical Society
- 出版年：2007
- 出版时间：August 29, 2007
- 年：2007
- 卷：129
- 期：34
- 页码：10512 - 10521
- 全文大小：357K
- 年卷期：v.129,no.34(August 29, 2007)
- ISSN：1520-5126
文摘
Heterospin complexes [Cu(SQ)2Py]·C7H8, Cu(SQ)2DABCO, and [Cu(SQ)2NIT-mPy]·C6H6, whereCu(SQ)2 is bis(3,6-di-tert-butyl-o-benzosemiquinonato)copper(II), DABCO is 1,4-diazabicyclo(2,2,2)octane,and NIT-mPy is the nitronyl nitroxide 2-(pyridin-3-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl, have been synthesized. The molecules of these complexes have a specific combination of theintramolecular ferro- and antiferromagnetic exchange interactions between the odd electrons of Cu(II) andSQ ligands, characterized by large exchange coupling parameters 
J 
100-300 cm-1. X-ray andmagnetochemical studies of a series of mixed-ligand compounds revealed that an extra ligand (Py, NIT-mPy, or DABCO) coordinated to the metal atom produces a dramatic effect on the magnetic properties ofthe complex, changing the multiplicity of the ground state. Quantum chemical analysis of magnetostructuralcorrelations showed that the energy of the antiferromagnetic exchange interaction between the odd electronsof the SQ ligands in the Cu(SQ)2 bischelate is extremely sensitive to both the nature of the extra ligandand structural distortions of the coordination unit, arising from extra ligand coordination.
J 100-300 cm-1. X-ray andmagnetochemical studies of a series of mixed-ligand compounds revealed that an extra ligand (Py, NIT-mPy, or DABCO) coordinated to the metal atom produces a dramatic effect on the magnetic properties ofthe complex, changing the multiplicity of the ground state. Quantum chemical analysis of magnetostructuralcorrelations showed that the energy of the antiferromagnetic exchange interaction between the odd electronsof the SQ ligands in the Cu(SQ)2 bischelate is extremely sensitive to both the nature of the extra ligandand structural distortions of the coordination unit, arising from extra ligand coordination.