A neutral paddlewheel-type diruthenium(III) complex with benzamidinato ligands: Synthesis, crystal structure, magnetism, and electrochemical and absorption properties

A new neutral diruthenium(III) complex coordinated with benzamidinato (bam) ligands, [Ru2(bam)4Cl2]·H2O (1), was synthesized and characterized, and its electronic structure was closely investigated via magnetic susceptibility, absorption spectrum, cyclic voltammetry, and density functional theory (DFT) calculations. Single crystal X-ray diffraction analysis revealed that complex 1 has a typical paddlewheel-type structure with a RuRu bond (bond length: 2.342(1) A), in which the diruthenium (Ru2) core is coordinated by four equatorially μ-bridging bam ligands and two axial Cl− ions. The magnetic study and DFT calculations proved that complex 1 has a triplet spin state (S = 1) and a unique electronic structure (π4δ2π*2σ2). Absorption spectral feature and electrochemical property of complex 1 were also carefully investigated both experimentally and theoretically in this study.