Synthesis and characterization of Ru2(DMBA)4X2 (X = CN, N3, N(CN)2, I):: Controlling structural, redox, and magnetic properties with axial ligands

Metathesis reactions between Ru-2(DMBA)(4)Cl-2 (DMBA = N,N'-dimethylbenzamidinate) and MX (M = Na and K) yielded bis-adduct derivatives Ru-2(DMBA)(4)X-2 (X = CN (1), N-3 (2), N(CN)(2) (3)). Metathesis reactions between Ru-2(DMBA)(4)(NO3)(2) and KI resulted in RU2(DMBA)(4)\(2) (4). Compound 1 is diamagnetic, while compounds 2-4 are paramagnetic (S = 1). Both compounds 1 and 2 undergo two reversible one-electron processes, an oxidation and a reduction, while compound 3 features a quasireversible reduction. Single-crystal X-ray diffraction studies revealed that the Ru-Ru bond lengths are 2.4508(9), 2.3166(7), 2,304[1], and 2.328(1) Angstrom for compounds 1-4, respectively. Structural and electrochemical data clearly indicate that the axial ligands impart a significant influence on the electronic structures of diruthenium species.