The synthesis and characterisation of some indenylophane clusters [M4H(CO)(9)(L-H)] (M = Ru or Os)

In a study concerning the reactivity of the [M-3(CO)(12)] (M=Ru or Os) clus ters towards the [2.2]parabenzoindenophane (L-1) and anti-[2.2]indenophane (L-2) ligands, the molecular structures of three new compounds [Ru4H(CO)(9) (L-1-H)] 1, [Os4H(CO)(9)(L-1-H)] 2 and [Ru4H(CO)(9)(L-2-H)] 3 were establis hed by single crystal X-ray diffraction analyses. In all cases it was obser ved that the ligand had undergone C-H bond activation with the resultant in denyl and hydride fragments retained upon the metal cluster in the facial m u(3)-eta(5):eta(2):eta(2) and edge-bridging mu modes, respectively. Surpris ingly, despite possessing two indene faces for cluster association, L-2 als o appears only to be able to utilise one of them.