Mutual interdependence of spin crossover and metal-metal bond formation in M2Cl93- (M = Fe, Ru, Os)

被引:30
作者
Lovell, T
Stranger, R [1 ]
McGrady, JE
机构
[1] Australian Natl Univ, Dept Chem, Canberra, ACT 0200, Australia
[2] Univ York, Dept Chem, York YO10 5DD, N Yorkshire, England
关键词
D O I
10.1021/ic0004737
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
Broken-symmetry density functional theory is used to examine the coupling between metal ions in the face-shared bioctahedral complexes M2Cl93-, M = Fe, Ru, Os. In the ruthenium and osmium systems, the metal ions have low-spin configurations, and strong coupling results in the formation of a metal-metal sigma bond. In contrast, the iron system contains two weakly coupled high-spin Fe-III centers, the different behavior being due to the high spin-polarization energy in the smaller Fe atom. At Fe-Fe separations shorter than 2.4 Angstrom, however, an abrupt transition occurs and the ground state becomes very similar to that for the heavier congeners (i.e., strongly coupled low-spin Fe-III). The intrinsic link between high-spin/low-spin transitions on the individual metal centers and the onset of metal-metal bond formation is traced to the spin-polarization energy, which plays a central role in both processes.
引用
收藏
页码:39 / 43
页数:5
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