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

Abstract

In a study concerning the reactivity of the [M₃(CO)₁₂] (M = Ru or Os) clusters towards the [2.2]parabenzoindenophane (L¹) and anti-[2.2]indenophane (L²) ligands, the molecular structures of three new compounds [Ru₄H(CO)₉(L¹ – H)] 1, [Os₄H(CO)₉(L¹ – H)] 2 and [Ru₄H(CO)₉(L² – H)] 3 were established by single crystal X-ray diffraction analyses. In all cases it was observed that the ligand had undergone C–H bond activation with the resultant indenyl and hydride fragments retained upon the metal cluster in the facial µ₃-η⁵∶η²∶η² and edge-bridging µ modes, respectively. Surprisingly, despite possessing two indene faces for cluster association, L² also appears only to be able to utilise one of them.