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(mu(2)-SH)(2)RuClCp*] (1) reacted with an excess of triethylamine to give the cubane-type tetraruthenium sulfide cluster [(Cp*Ru)(4)-(mu(3)-S)(4)] (3) When the reaction was carried out in the presence of alkynes, the dithiolene-bridged diruthenium complexes [(Cp*Ru)(2)(mu(2)-eta(2):eta(4)-S2C2RR')] (4) were obtained. The dithiolene ring in 4 is almost planar. Treatment of 4 with CO afforded the carbonyl complexes [Cp*Ru(CO)(mu(2)-eta(2):eta(4)-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 sulfide cluster [(Cp*Ru)(2)(mu(3)-S)(2)(mu(2)-H)RuCl(PPh3)(2)] (6). Cluster 6 reacted with an excess of NaBH4 in ethanol to give the dihydrido cluster [(Cp*Ru)(2)(mu(3)-S)(2)(mu(2)-H)RuH(PPh3)(2)] (7), which was further converted to the dicarbonyl cluster [(Cp*Ru)(2)(mu(3)-S)(2)Ru(CO)(2)(PPh3)] (8) under CO. The detailed structures for [(Cp*RU)(2)(mu(2)-eta(2):eta(4)-S2C2HBut)] (4a), [Cp*Ru(CO)(mu(2)-eta(2):eta(4)-S2C2HBut)RuCp*] (5a), and 6-8 have been determined by X-ray crystallography.