Pentasulfide S₅^2- as the First Tridentate Chelating Ligand in Ru(P(OE)₃)₃S₅(E = Me and Et)

Abstract

Room temperature stirring of H2Ru(P(OE)3)4 (E = Me and Et) and elemental sulfur in benzene afforded the optically active compounds Ru(P(OMe)3)3S5 (1) and Ru(P(OEt)3)3S5 (2). Compounds 1 and 2 are crystallized in the trigonal space group P31 with a = 14.231(10) A, c = 10.24(1) A, V = 1794(2) A3, and Z = 3, and orthorhombic space group P212121 with a = 15.393(5) A, b = 18.126(6) A, c = 12.421(4) A, V = 3465(1) A3, and Z = 4, respectively. Solutions of 1 and 2 did not show any optical activity since the bulk materials are racemic mixtures. The X-ray analyses also reveal that in both compounds polysulfide S5(2-) ion acts as a novel tridentate ligand, resulting in an asymmetric bicyclic RuS5 unit having three- and five-membered rings around the ruthenium atom. Fragmentation of the S5(2-) ring to S2- ion was observed in the presence of sulfur-abstracting reagents such as PR3 (R = Ph, OMe, and OEt) and also to S2(2-) ion when the compounds were reacted with RuCl2(P(OE)3)4 (E = Me and Et).

Syntheses of a Cp‘ReS Derivative and More Complex Products

“…Many examples of metal complexes with di- or polysulfide ligands are known, , and their reactions with nucleophiles, such as phosphines, often provide a route to new metal sulfido derivatives through the elimination of one or more equivalents of phosphine sulfide. ,− The formation of complexes with terminal sulfido ligands is of particular interest because of the potential for comparisons in reactivity and electronic structures with a range of multiply bonded terminal ligands from groups 14 through 16. , We have recently reported the synthesis of a mononuclear trisulfide complex of Re(V), Cp‘Re(η 2 -S 3 )Cl 2 , 1 , and have studied its reaction with hydrogen which proceeds to remove one sulfur atom from the trisulfide ligand, as well as the chloride ligands, as shown in eq 1 …”