INOR 347 |
| Mixed valence Mn/O dinuclear and polynuclear molecular compounds containing MnIII are almost without exception valence-localized (Class II). Large differences between the strengths of the exchange interactions within MnIIMnIII, MnIIIMnIII and MnIIIMnIV pairs lead to situations where MnIIIMnIV interactions, the strongest of the three mentioned and antiferromagnetic in nature, dominate the intramolecular spin alignments in trinuclear and higher nuclearity complexes and often result in molecules that have large, and sometimes abnormally large values of molecular spin (S). When coupled to a large molecular magnetoanisotropy of the easy-axis type (negative zero-field splitting parameter D), also primarily resulting from individual Jahn-Teller distorted MnIII centers, these molecules will function as single-molecule magnets (molecular nanomagnets). Such situations will be analyzed in detail in this talk by discussion of the structures and exchange interactions within a variety of mixed valence Mnx cluster molecules with various metal nuclearities, providing a rationalization of the experimentally observed magnetic properties. |
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Mixed Valency in Chemistry
8:30 AM-11:20 AM, Monday, August 20, 2007 BCEC -- 205B, Oral
Division of Inorganic Chemistry |