Aerobic oxidation of methyl p-tolyl sulfide catalyzed by a remarkably labile heteroscorpionate Ru(II)-aqua complex, fac-[RuII(H2O)(dpp)(tppm)]2+

fac-[RuII(Cl)(dpp)(L3)]+ (L3 = tris(pyrid-2-yl)methoxymethane (tpmm) = [1A]+ and tris(pyrid-2-yl)pentoxymethane (tppm) = [1B]+ and dpp = di(pyrazol-1-yl)propane) rapidly undergo ligand substitution with water to form fac-[RuII(H2O)(dpp)(L3)]2+ (L3 = tpmm = [2A]2+ and tppm = [2B]2+). In the structure of [2A]2+, the distorted octahedral arrangement of ligands around Ru is evident by a long Ru(1)-O(40) of 2.172(3) Å and a large (40)-Ru (1)-N(51) of 96.95(14)° The remarkably short distance between O (40) of H 2O and H (45a) of dpp confirms the heteroscorpionate ligand effect fo dpp H 2O [2B] 2+ aerobically catalyzes methl p-toyl sulfide to methyl p-toyl sulfoxide in 1,2 dichlorobenzene at 25.0 ± 0.1 ° C under 11.4 psi of O2.Experimental facts in support of this aerobic sulfide oxidation are the absence of H 2O2 and the oxidative readctive of the putative Ru(IV)-oxo intermediate toward methl p-tolyl Sulfide, 2- propanol, and allyl alcohal This study provides the first documented example of aerobic-sulfide oxidation catalyzed by the remarkably labile heteroscorpionate Ru (III)- aqua complex without the formation of a highly reactive peroxide as an intemediate. Copyright © 2003 American Chemical Society.