The three square planar complexes [N(n-Bu)(4)](2)[(CrL2)-L-II]center dot 4CH(3)CN (S=2; 1), [N(n-Bu)(4)][(CoL2)-L-III] (S=1; 3), and [N(n-Bu)(4)](2)[(RhL2)-L-II]center dot 4CH(3)CN (S=1/2; 4) have been prepared and structurally characterized by X-ray crystallography (L2-represents the 3,6-bis(trimethylsilyl)benzene-1,2-dithiolate(2-)). Aerial oxidation of CH2Cl2 solutions of 1 produced purple crystals of [N(n-Bu)(4)][(CrOL2)-O-V]center dot 2CH(2)Cl(2) (S=1/2; 2), the structure of which has also been determined by X-ray crystallography. The electro- and magnetochemistry of all species has been studied. Their electronic structures have been experimentally investigated by recording their electronic and EPR spectra; solid-state temperature-dependent magnetic susceptibility measurements have been performed. Density functional theoretical calculations at the ZORA-B3LYP level have been carded out for all four species in order to obtain a better understanding of the electronic structure of the square planar complexes and the one-electron reduced [(RhL2)-L-I](3-) species. The reactivity of the latter with CH(3)l has been studied, and two products have been identified: cis-[Rh(III)l(2-) (L '')(L')] and cis-[Rh-III(CH3)(l)(L '')(L')]where (L')(-) represents the S-methylated monoanion of L2- and (L '')(0) is the neutral, twice-S-methylated form of (L)(2-).