Group 9 half-sandwich complexes containing the unique P,P′-diphenyl-1,4-diphospha-cyclohexane ligand: Synthesis, X-ray structure analyses and spectroscopic studies

We wish to report the synthesis and characterization of Group 9 metal complexes with the novel P,P′-diphenyl-1,4-diphospha-cyclohexane (dpdpc) ligand. The complexes are readily prepared by direct ligand substitution reactions from the dichloro-bridged binuclear complexes, [{η5-Cp*M(Cl)2}2]. The complexes include: [η5-Cp*Rh(Cl)2]2(μ-dpdpc) (1), [η5-Cp*Ir(Cl)2]2(μ-dpdpc) (2), and [η5-Cp*Rh(Cl)(dpdpc)]PF6 (3). The structures for all three complexes are supported by 1H, 13C{1H}, and 31P{1H} NMR spectroscopy as well as elemental analysis. The molecular structures of 1 and 3 have also been established by single-crystal X-ray analysis.