Benzene in a new face-capping bonding mode: molecular structures of [Ru ₆ C(CO) ₁₁ (µ ₃ -η ² : η ² :η ² -C ₆ H ₆ )(η ⁶ -C ₆ H ₆ )] and [Os ₃ (CO) ₉ (µ ₃ -η ² : η ² :η ² -C ₆ H ₆ )]

A new co-ordination mode for benzene ligands in cluster complexes, in which the ring is symmetrically placed above a metal triangle has been crystallographically established in the carbonyl complexes [Ru6C(CO)11(µ3-η2: η2:η2-C6H6)(η6-C6H6)] and [Os3(CO)9(µ3-η2: η2:η2-C6H6)].