Synthesis and characterization of triosmium and triruthenium pyrene clusters

The reaction between 1-pyrenecarboxaldehyde (C16H9CHO) and the labile triosmium cluster [Os3(CO)10(CH3CN)2] gives rise to the formation of two new compounds by competitive oxidative addition between the aldehydic group and an arene C–H bond, to afford the acyl complex [Os3(CO)10(μ-H)(μ-COC16H9)] (1) and the compound [Os3(CO)10(μ-H) (C16H8CHO)] (2), respectively. Thermolysis of [Os3(CO)10(μ-H)(μ-C16H9CO)] (1) in n-octane affords two new complexes in good yields, [Os3(CO)9(μ-H)2(μ-COC16H8)] (3) and the pyryne complex [Os3(CO)9(μ-H)2(μ3-η1:η1:η2-C16H8)] (4). In contrast, when 1-pyrenecarboxaldehyde reacts with [Ru3(CO)12] only one product is obtained, [Ru3(CO)9(μ-H)2(μ3-η1:η1:η2-C16H8)] (5), a nonacarbonyl cluster bearing a pyrene ligand. All compounds were characterized by analytical and spectroscopic data, and crystal structures for 1, 2, 4 and 5 were obtained.