As a development of our recent works about the magnetic study for heterodinuclear clusters, a covalent effect has been introduced in the magnetic exchange interaction formula and a more general magnetic expression for heterodinuclear transition-metal ion pairs in covalent complexes has been derived. By means of this expression and our double-Slater function (DSF) calculation procedure, the relationship between the magnetic exchange coupling parameter J and the covalent factors N-A and NB for a heterodinuclear system A-B has been studied. For the heterodinuclear Fe-III(a(3))-Cu-II(B) pair in beef heart cytochrome c oxidase, it is demonstrated that the stronger the covalent effect the stronger the antiferromagnetic coupling. The theoretical curve of the magnetic exchange interaction J vs. the values of the Fe-III(a(3))-Cu-II(B) separation R and the covalent factors N-A (for Fe-III) and NB (for Cu-II) has been obtained. It is shown that the strong antiferromagnetic phenomenon for the heterodinuclear Fe-III(a(3))-Cu-II(B) pairs in cytochrome c oxidase can be attributed to the combined effect of the direct-exchange interaction, the kinetic exchange interaction and the covalent effect. It is also shown that in order to reproduce the very strong antiferromagnetic exchange interaction J (-J greater than or equal to 200 cm(-1)) in cytochrome c oxidase the theoretical range of the Fe-III(a(3))-Cu-II(B) separation R should be smaller than 4.0 A. This result is obviously smaller than the value R-expt = 4.5 A reported by Tsukihara et al. and Iwata et al., but it is in good agreement with the value R-expt less than or equal to 4 A obtained by Scott et al. and Powers et al. from their EXAFS experiments. (C) 2002 Elsevier Science B.V. All rights reserved.
部门归属
sichuan univ, dept phys, chengdu 610064, peoples r china. sichuan univ, inst atom & mol phys, chengdu 610065, peoples r china. acad sinica, int ctr mat phys, shenyang 110015, peoples r china. ccast, world lab, beijing 100080, peoples r china.;zhou, kw (reprint author), sichuan univ, dept phys, chengdu 610064, peoples r china
X. Y. Kuang,K. W. Zhou. Theory of magnetic exchange interaction for heterodinuclear Fe-III(a(3))-Cu-II(B) in cytochrome c oxidase[J]. Physics Letters A,2002,299(4):407-412.
APA
X. Y. Kuang,&K. W. Zhou.(2002).Theory of magnetic exchange interaction for heterodinuclear Fe-III(a(3))-Cu-II(B) in cytochrome c oxidase.Physics Letters A,299(4),407-412.
MLA
X. Y. Kuang,et al."Theory of magnetic exchange interaction for heterodinuclear Fe-III(a(3))-Cu-II(B) in cytochrome c oxidase".Physics Letters A 299.4(2002):407-412.
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