Synthesis and characterisation of hexa- and hepta-ruthenium carbido carbonyl clusters containing arenes derived from 1,1-diphenylethene

The three ruthenium arene clusters [Ru6C(CO)14(η6-PhCHMePh)] 1, [Ru6C(CO)14(η6-PhCCH2Ph)] 2 and [Ru7C(CO)14(µ3-κ∶η6∶η6-C6H4CH2C6H4)] 3 have been synthesized by reaction of 1,1-diphenylethene with triruthenium dodecacarbonyl in octane under reflux. Compound 1 is a 1,1-diphenylethene hexaruthenium carbido cluster (Ru6C) derivative wherein the organo-group, hydrogenated at the olefinic centre, is bound to the cluster by a single phenyl ring in an η6 manner. Compound 2 is a similar Ru6C derivative wherein the 1,1-diphenylethene ligand remains unsaturated, whilst the third, and minor, product is the first example of a metal carbonyl cluster chelated by a diphenyl ligand and is one of the few examples of an Ru7C ‘spiked’ octahedron. The subtle electronic effects of the Ru6C co-ordination in 2 have been probed by 1H NMR spectroscopy. The solid-state structures of both the hydrogenated derivative 1 and the Ru7C ‘spiked’ octahedral cluster 3 have been determined by single-crystal X-ray analysis. The supramolecular architecture of 3 has been examined in depth.