The chemistry of [M3(CO)10(μ-dppm)](M = Ru, Os): Activating and maintaining the trinuclear core

Ruthenium and osmium dodecacarbonyls, M3(CO)12 (M = Ru, Os), find extensive use as precursors towards a range of low-valent ruthenium and osmium compounds, being especially widely utilized in the area of cluster chemistry. However, especially in the case of Ru3(CO)12, the generally desired carbonyl loss competes with metal–metal bond cleavage such that a range of products of varying nuclearities result. In contrast, related complexes [M3(CO)10(μ-dppm)] in which two equatorial carbonyls are replaced by the small bite-angle diphosphine, bis(diphenylphosphino)methane (dppm), are both relatively activated with respect to further carbonyl loss while also serving to maintain the integrity of the trinuclear core. This makes them attractive starting materials for a range of trinuclear cluster chemistry which is the subject of this review.