Aerobic oxidation of methyl p-tolyl sulfide catalyzed by a remarkably labile heteroscorpionate RuII-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) A and a large angle O(40)-Ru(1)-N(51) of 96.95(14) degrees . The remarkably short distance between O(40) of H2O and H(45a) of dpp confirms the heteroscorpionate ligand effect of dpp on H2O. [2B]2+ aerobically catalyzes methyl p-tolyl sulfide to methyl p-tolyl sulfoxide in 1,2-dichlorobenzene at 25.0 +/- 0.1 degrees C under 11.4 psi of O2. Experimental facts in support of this aerobic sulfide oxidation are the absence of H2O2 and the oxidative reactivity of the putative Ru(IV)-oxo intermediate toward methyl p-tolyl sulfide, 2-propanol, and allyl alcohol. This study provides the first documented example of aerobic-sulfide oxidation catalyzed by the remarkably labile heteroscorpionate Ru(II)-aqua complex without the formation of a highly reactive peroxide as an intermediate.
Huynh
My Hang V
MH
Department of Chemistry, State University of New York at Buffalo, 14260, USA. huynh@lanl.gov
Witham
Laura M
LM
Lasker
Joanne M
JM
Wetzler
Modi
M
Mort
Brendan
B
Jameson
Donald L
DL
White
Peter S
PS
Takeuchi
Kenneth J
KJ
D002384:Catalysis; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D016877:Oxidants / Q000737:chemistry; D010084:Oxidation-Reduction; D012428:Ruthenium / Q000737:chemistry*; D013440:Sulfides / Q000737:chemistry*
D009942:Organometallic Compounds; D016877:Oxidants; D013440:Sulfides; C472023:aqua(tris(pyrid-2-yl)methoxymethane)(di(pyrazol-1-yl)propane)ruthenium(II); D012428:Ruthenium