Effects of axial ligands on the oxidation state, structure, and electronic configuration of diruthenium complexes. Synthesis and characterization of Ru2(dpf)4Cl, Ru(dpf)4(C(triple bond)CC6H5), Ru2(dpf)4(C(triple bond)CC6H5)2, and Ru2(dpf)4(CN)2 (dpf = N,N'-diphenylformamidinate)

The oxidation states, magnetic properties, and electronic configuration of Ru2(dpf)4Cl (1), Ru2(dpf)4(C(triple bond)CC6H5) (2), Ru2(dpf)4(C(triple bond)CC6H5)2 (3), and Ru2(dpf)4(CN)2 (4) (dpf=N,N'-diphenylformamidinate) are analyzed by X-ray diffraction, 13C NMR, and VU-visible spectroscopy. Compounds 2, 3, and 4 are prepared from Ru2(dpf)4Cl and Li(C(triple bond)CC6H5). Compounds 3 and 4 are diamagnetic and become paramagnetic on heating at controlled-potential reduction. The bond distance of these Ru complexes are analyzed by electrochemistry. The synthesis of 1 is discussed.