Molecular and electronic structure of the dithiooxalato radical ligand stabilised by rare earth coordination

Heterometallic rare earth transition metal compounds of dithioxalate (dto)(2-), [Ni-II{(dto)Ln(III)Tp(2)}(2)] (Ln = Y (1), Gd (2); Tp = hydrotris(pyrazol-1-yl)borate) were synthesised. The Lewis acidic rare earth ions are bound to the dioxolene and chemical reduction of 1 and 2 with cobaltocene yielded [CoCp2](+)[Ni-II{(dto)Ln(III)Tp(2)}(2)](center dot-) Ln = Y (3), Gd (4). The reduction is ligand-based and 3 and 4 are the first examples of both molecular and electronic structural characterisation of the dithiooxalato radical (dto)(3 center dot-).