Structures and Reactivities of Diruthenium Dithiolene Complexes and Triruthenium Sulfido Clusters Derived from a Hydrosulfido-Bridged Diruthenium Complex

The hydrosulfido-bridged diruthenium complex [Cp*RuCl(μ₂-SH)₂RuClCp*] (1) reacted with an excess of triethylamine to give the cubane-type tetraruthenium sulfido cluster [(Cp*Ru)₄(μ₃-S)₄] (3). When the reaction was carried out in the presence of alkynes, the dithiolene-bridged diruthenium complexes [(Cp*Ru)₂(μ₂-η²:η⁴-S₂C₂RR‘)] (4) were obtained. The dithiolene ring in 4 is almost planar. Treatment of 4 with CO afforded the carbonyl complexes [Cp*Ru(CO)(μ₂-η²:η⁴-S₂C₂RR‘)RuCp*] (5) containing a bent dithiolene ring. On the other hand, the reaction of 1 with an equimolar amount of [RuH₂(PPh₃)₄] resulted in the formation of the triruthenium sulfido cluster [(Cp*Ru)₂(μ₃-S)₂(μ₂-H)RuCl(PPh₃)₂] (6). Cluster 6 reacted with an excess of NaBH₄ in ethanol to give the dihydrido cluster [(Cp*Ru)₂(μ₃-S)₂(μ₂-H)RuH(PPh₃)₂] (7), which was further converted to the dicarbonyl cluster [(Cp*Ru)₂(μ₃-S)₂Ru(CO)₂(PPh₃)] (8) under CO. The detailed structures for [(Cp*Ru)₂(μ₂-η²:η⁴-S₂C₂HBu^t)] (4a), [Cp*Ru(CO)(μ₂-η²:η⁴-S₂C₂HBu^t)RuCp*] (5a), and 6−8 have been determined by X-ray crystallography.