Synthesis and structural characterization of a photoresponsive organodirhodium complex with active S–S bonds: [(CpPhRh)2(μ-CH2)2(μ-O2SSO2)] (CpPh = η5-C5Me4Ph)

A photoresponsive rhodium dinuclear complex having phenyltetramethylcyclopentadienyl (CpPh = η5-C5Me4Ph) and photosensitive dithionite (μ-O2SSO2) ligands, [(CpPhRh)2(μ-CH2)2(μ-O2SSO2)] (1), has been synthesized. The crystal of complex 1 (monoclinic, C2/m (No. 12), a = 24.805(2) Å, b = 29.111(2) Å, c = 10.8475(11) Å, β = 105.9830(7)°, V = 7530.0(12) Å3, Z = 8) consists of two independent molecules, 1-cis and 1-trans, with different arrangement of the CpPh ligands. The flexibility, volume, and shape of the reaction cavities around the dithionite unit of 1-cis and 1-trans in the crystal are discussed. The crystal structures of the precursors of 1, trans-[(CpPhRh)2(μ-Cl)2Cl2] and trans-[(CpPhRh)2(μ-CH2)2Me2], are also reported.