Synthesis of η-arene rhenium compounds using rhenium atoms. Crystal structures of [Re2(η-C6H6)(η-C6H8)2(µ-H)2] and [Re(η-C6H6)(η-C6H8)H]
The new compounds [Re2(η-C6H6)(η-C6H8)2(µ-H)2], [Re(η-C6H6)(η-C6H8)H], [Re(η-C6H6)(η5-C7H7)], [Re(η-C6H6)(η5-C7H9)], and [Re(η5-C9H7)(η6-C9H8)] are described, including the determination of the crystal structures of the first two compounds. The new compounds have been made by co-condensation of rhenium atoms with benzene–cyclohexene, benzene–cyclohexa-1,3-diene (or cyclohexene), benzene–cycloheptatriene, benzene–cycloheptatriene, and pure indene, respectively. Co-condensation of rhenium atoms with benzene–cyclopentadiene yields a mixture of [Re(η-C6H6)(η-C5H5)] and [Re(η-C5H5)2H]. Characterisation of the η-cycloheptatriene and η-indene derivatives required two-dimensional (1H–1H) COSY and (13C–1H) correlation n.m.r. spectroscopy. Co-condensation of rhenium atoms with cyclohexane–trimethylphosphine gives [Re(η-C6H6)(PMe3)2H] where the η-benzene ligand derives from the cyclohexane.