Triruthenium clusters containing bridging dppm and capping sulfido and selenido ligands: X-ray structures of [Ru 3(CO) 5(μ 3-CO)(μ 3-Se)(μ-dppm) 2], [Ru 3(CO) 6(μ 3-CO)(μ 3-Se)(μ-dppm)(η 1-Ph 2PCH 2P( [dbnd]O)Ph 2)] and [Ru 2(CO) 4(μ-SePh) 2(μ-dppm)

Abstract

The reaction of [Ru 3(CO) 10(μ-dppm)] ( 1) with dppmSe at 66 °C affords [Ru 3(CO) 8(μ-dppm) 2] ( 2), [Ru 3(CO) 7(μ 3-CO)(μ 3-Se)(μ-dppm)] ( 3), [Ru 3(CO) 5(μ 3-CO)(μ 3-Se)(μ-dppm) 2] ( 4) and [Ru 3(CO) 6(μ 3-CO)(μ 3-Se)(μ-dppm)(η 1-Ph 2PCH 2P( O)Ph 2)] ( 5) in 7%, 5%, 9% and 33% yields, respectively. A similar reaction between 1 with dppmS gives [Ru 3(CO) 7(μ 3-S) 2(μ-dppm)] ( 6), [Ru 3(CO) 7(μ 3-CO)(μ 3-S)(μ-dppm)] ( 7) [Ru 3(CO) 5(μ 3-CO)(μ 3-S)(μ-dppm) 2] ( 8) and [Ru 3(CO) 6(μ 3-CO)(μ 3-S)(μ-dppm)(η 1-Ph 2PCH 2P( O)Ph 2)] ( 9) in 8%, 7%, 14% and 35% yields, respectively. Treatment of 1 with PhSeSePh at 66 °C affords the dinuclear compound [Ru 2(CO) 4(μ-SePh) 2(μ-dppm)] ( 10) in 14% yield. Thermolysis of 5 and 9in refluxing toluene at 110 °C gives 4 and 8, respectively. The molecular structures of 4, 9 and 10 have been determined by single-crystal X-ray diffraction studies. The cores of the new clusters 4, 5, 8 and 9 consist of metal triangles capped by μ 3-sulfur or selenium atoms with the bidentate ligand bridging in equatorial positions. In compounds 4 and 8, two bidentate dppm ligands bridge the Ru 3 triangle in such a way that each ligand bridges two ruthenium atoms and one Ru–Ru edge remains unbridged. Compounds 5 and 9 contain one bridging dppm ligand and one dangling dppm mono-oxide ligand Ph 2PCH 2P( O)Ph 2 coordinated to the rear metal atom at an equatorial position. The molecular structure of 10 shows classical “sawhorse” structure with two bridging SePh ligands as well as the dppm ligand.