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

fac-[Ru^II(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-[Ru^II(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.