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

Treatment of [Ru-3(CO)(10)(mu-dppm)] (4) [dppm = bis(diphenylphosphido)methane] with tetramethylthiourea at 66 degrees C gave the previously reported dihydrido triruthenium cluster [Ru-3(mu-H)(2)(mu(3)-S)(CO)(7)(mu-dppm)] (5) and the new compounds [Ru-3(mu(3)-S)(2)(CO)(7)(mu-dppm)] (6), [Ru-3(mu(3)-S)(CO)(7)(mu(3)-CO)(mu-dppm)] (7) and [Ru-3(mu 3-S)eta(I)-C(NMe2)(2)}(CO)(6)(mu(3)-CO)(mu-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 degrees C to yield 6 (30%) and a new compound [Ru-3(mu(3)-S)(2){mu(3)-C(NMe2)(2)}(CO)(6)(mu-dppm)] (9) (8%). Thermolysis of 8 in refluxing THF yields 7 in 55% yield. The reaction of 4 with selenium at 66 degrees C yields the new compounds [Ru-3(mu(3)-Se)(CO)(7)(mu(3)-CO)(mu-dppm)] (12) and [Ru-4(mu(3)-Se)(mu(3)-eta(3)-PhPCH2PPh(C6H4)(CO)(6)(mu-CO)] (11) and the known compounds [Ru-3(mu-H)(2)(mu(3)-Se)(CO)(7)(mu-dppm)] (12) and [Ru-4(mu(3)-Se)(4)(CO)(6)(mu-dppm)] (13) in 29%, 5%, 2% and 5% yields, respectively. Treatment of 10 with tetramethylthiourea at 66 degrees C gives the mixed sulfur-selenium compounds [Ru-3(mu(3)-S)([mu(3)-Se)(CO)(7)(mu-dppm)] (14) and [Ru-3(mu(3)-S)(mu(3)-Se){eta(1)-C(NMe2)(2)}(CO)(6)(mu-dppm)] (15) in 38% and 10% yields, respectively. The single-crystal XRD structures of 6, 7, 8, 10, 14 and 15 are reported.