Structural and Spectroscopic Characterization of a Metal−Metal Bonded Ruthenium Porphyrin Dimer Cation

The crystal structure, ESR, and solution magnetic susceptibility of a cationic porphyrin dimer, [Ru(TPP)]2PF6 (TPP = 5,10,15,20-tetraphenylporphyrinato dianion) are reported. The structure exhibits an Ru−Ru bond length of 2.293(2) Å, which is characteristic of Ru25+ centers. ESR (g⊥ = 1.993, g∥ = 1.953) and solution magnetic moment (μeff = 1.85 BM) measurements are consistent with a molecular orbital diagram, σ2π4δ2δ*2π*1, which differs from that observed for isoelectronic Ru25+ systems with bridging ligands.