Spectroscopic and kinetic studies of the reaction of [CuI(6-PhTPA)]+ with O2.
Oxygenation of [Cu(I)(6-PhTPA)](SbF(6)) in acetone at -90 degrees C produces a short-lived Cu(III)(2)(mu-O)(2) intermediate that exhibits an oxygen-isotope-sensitive nu(Cu-O) mode at 599 cm(-1) and an overtone at 1192 cm(-1). The formation of this intermediate is very fast and is second-order in copper(I) complex, implying that two copper-containing species interact in the rate-limiting step or in pre-equilibrium steps prior to the rate determining step. The decay of this intermediate was facile even at -90 degrees C but did not afford any arene hydroxylation product. Interestingly, the effect of introducing a 6-phenyl substituent on the TPA ligand framework differs from that of a 6-methyl substituent, providing access to a bis(mu-oxo)dicopper(III) intermediate in the former and a (mu-1,2-peroxo)dicopper(II) species in the latter.
Jensen
Michael P
MP
Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455, USA.
Que
Emily L
EL
Shan
Xiaopeng
X
Rybak-Akimova
Elena
E
Que
Lawrence
L
D000096:Acetone / Q000737:chemistry; D003300:Copper / Q000737:chemistry; D018360:Crystallography, X-Ray; D006900:Hydroxylation; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D009942:Organometallic Compounds / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D013059:Spectrum Analysis, Raman
D009942:Organometallic Compounds; D000096:Acetone; D003300:Copper; D010100:Oxygen