A dinuclear cation with both four- and five-coordinate cobalt(II)

The reaction of cobalt dichloride with the lithium salt of 2,6-diphenylimin opiperidine, Li(DPhIP), leads to the Co-2(DPhIP)(3)(+) cation. The DPhIP li gands in this cation each coordinate in such a way that two adjacent nitrog en atoms are chelated to one cobalt atom while the remaining one is bonded to the other cobalt atom. This leads to a structure in which one Con ion is four-coordinate while the other is five-coordinate. The Co-Co distance of ca. 3.1 Angstrom implies that:there is no direct metal to metal bonding.