Kinetic and thermodynamic studies of reversible adduct formation between Ru5C(CO)15 and acetonitrile

Stopped-flow kinetic measurements have been made on the reversible addition of NCMe to Ru5C(CO)15 in 1,2-dichloroethane to form the adduct in which a RuRu bond in the cluster has been broken and replaced by a RuNCMe bond. The measurements lead to the kinetic parameters kf (25°C)=24.3±1.4 M−1 s−1, ΔHf≠=31.7±3.5 kJ mol−1 and ΔSf≠=−91±12 J K−1 mol−1; kr (25°C)=296±18 s−1, ΔHr≠=51.0±1.3 kJ mol−1 and ΔSr≠=−47±4 J K−1 mol−1. Addition of NCMe …