Substituted metal carbonyls. Part 9. Solution and solid-state decompositions of diphosphine-monobridged molybdenum carbonyl dimers

Abstract

Thermal decomposition of the singly-bridged complexes Mo2(CO)10[μ-Ph2P(CH2)nPPh2] (n=4, 5, 6) has been studied as hexane, benzene and toluene solutions by infrared monitoring and in the solid state by thermogravimetry and differential scanning calorimetry. The thermal profiles of the three complexes reveal a similar degradation pattern which involves an initial loss of CO followed by phosphine cleavage via a multi-step mechanism. The dimers are stable in boiling hexane but decarbonylate upon prolonged heating in toluene resulting in the cis- complexes Mo(CO)4(PP) which are 7-, 8- and 9-membered chelate rings. © 1989.