Structures, magnetic properties, and reactivity studies of salts containing the dinuclear anion (M(sub.2)Cl(sub.6))(super.2-) (M = Mn, Fe, Co)

Salts containing the dinuclear anion (M(sub.2)Cl(sub.6))(super.2-) (M = Mn, Fe, Co) are discussed relative to magnetic properties, structures and reactivities. The edge-sharing bitetrahedral anion was isolated with 5 different cations. The electronic ground state of the ion is orbitally degenerate and highly anisotropic, a conclusion confirmed with magnetic data. The bridging ligand mediates antiferromagnetic exchange. The D parameter is large and negative. High-spin polynuclear transition metal compounds are of interest for magnetic properties for biological use and for materials chemistry. Iron, or ferrous, compounds have not been studied well vs ferric systems.