Dppm-substituted ruthenium clusters with capping sulfido and selenido ligands derived from thiourea, tetramethylthiourea and elemental selenium

Treatment of [Ru3(CO)10(μ-dppm)] (4) [dppm = bis(diphenylphosphido)methane] with tetramethylthiourea at 66 °C gave the previously reported dihydrido triruthenium cluster [Ru3(μ-H)2(μ3-S)(CO)7(μ-dppm)] (5) and the new compounds [Ru3(μ3-S)2(CO)7(μ-dppm)] (6), [Ru3(μ3-S)(CO)7(μ3-CO)(μ-dppm)] (7) and [Ru3(μ3-S){η1-C(NMe2)2}(CO)6(μ3-CO)(μ-dppm)] (8) in 6%, 10%, 32% and 9% yields, respectively. Treatment of 4 with thiourea at the same temperature gave 5 and 7 in 30% and 10% yields, respectively. Compound 7 reacts further with tetramethylthiourea at 66 °C to yield 6 (30%) and a new compound [Ru3(μ3-S)2{η1-C(NMe2)2}(CO)6(μ-dppm)] (9) (8%). Thermolysis of 8 in refluxing THF yields 7 in 55% yield. The reaction of 4 with selenium at 66 °C yields the new compounds [Ru3(μ3-Se)(CO)7(μ3-CO)(μ-dppm)] (10) and [Ru3(μ3-Se)(μ3-η3-PhPCH2PPh(C6H4)}(CO)6(μ-CO)] (11) and the known compounds [Ru3(μ-H)2(μ3-Se)(CO)7(μ-dppm)] (12) and [Ru4(μ3-Se)4(CO)10(μ-dppm)] (13) in 29%, 5%, 2% and 5% yields, respectively. Treatment of 10 with tetramethylthiourea at 66 °C gives the mixed sulfur-selenium compounds [Ru3(μ3-S)(μ3-Se)(CO)7(μ-dppm)] (14) and [Ru3(μ3-S)(μ3-Se){η1-C(NMe2)2}(CO)6(μ-dppm)] (15) in 38% and 10% yields, respectively. The single-crystal XRD structures of 6, 7, 8, 10, 14 and 15 are reported.