The 3,5-di-tert-butyl substituted N-(salicylidene)-o-mercaptoaniline (H2L) ligand reacted with equimolar amounts of FeBr2 and 2 equiv of triethylamine in air affords [Fe-III(L-L)Br](0) (1), where (L-L)(2-) is a pentacoordinate ligand formed from the oxidative dimerization of L2-Via disulfide bridge formation. Reaction of H2L with RuCl3 center dot H2O and NEt3 gives a dark green-brown dinuclear complex, [Ru-2(III)(L)(2)Cl-2(NCCH3)(2)](0) (2). Both complexes have been characterized by X-ray crystallography. A Ru-Ru single bond is evident in 2. Complex 1 has also been characterized by electron paramagnetic resonance and Mossbauer spectroscopies and magnetic susceptibility measurements that identify a high-spin Fe(III) (S = 5/2) center. Diamagnetic 2 is successively twice reversibly one-electron oxidized to produce [Ru-2(III)(L-center dot)(L)Cl-2(NCCH3)(2)](+), [2](+) (S = 1/2), and [Ru-2(III)(L-center dot)(2)Cl-2(NCCH3)(2)](2+), [2](2+) (S = 0). Spectroelectrochemical and electron paramagnetic resonance measurements identify these as ligand-based oxidations affording o-coordinated phenoxyl radicals. DFT calculations on the electron transfer series corroborate this result and that the Ru-Ru single bond is retained throughout this series,