Synthesis, structure and optical limiting properties of organoruthenium–chalcogenide clusters

Treatment of Ru3(CO)12 with Ph3PS affords the compounds [Ru3(μ3-S)2(CO)9 − n(PPh3)n] (n = 1 (1a), 2 (2a)) and [Ru3(μ3-S)(μ3-CO)(CO)7(PPh3)2] (3a) as the major products. Single crystal X-ray diffraction studies of [Ru3(μ3-S)2(CO)8(PPh3)] and [Ru3(μ3-S)(μ3-CO)(CO)7(PPh3)2] show these two classes of compounds to contain square pyramidal Ru3S2 and trigonal pyramidal Ru3S metal cores, respectively, with the latter being isostructural to the analogous selenide cluster compound. The clusters [Ru3(μ3-E)2(CO)9 − n(PPh3)n] (E = S, n = 1; E = Se, n = 2) readily undergo ligand displacement reactions with PPh3 to afford the compounds [Ru3(μ3-E)2(CO)6(PPh3)3] (E = S, 5a; E = Se 5b). The mixed chalcogenide cluster, [Ru3(μ3-S)(μ3-Se)(CO)7(PPh3)2] (6), was prepared from the reaction of [Ru3(μ3-S)(μ3-CO)(CO)7(PPh3)2] and SePPh3. The optical limiting properties of the complexes 1a,b, 2a,b, 5a,b have been measured by the Z-scan technique employing 40 ns pulses at 523 nm; power limiting was observed for all clusters under our experimental conditions.