Mechanism of an Oxygen Atom Transfer Reaction Involving an Oxo-bridged Mo(V) Complex
Inorganica Chimica Acta
Kinetics and mechanism, Oxygen atom transfer, Molybdenum complexes, Oxo-bridged complexes
The kinetics of the oxygen atom transfer reaction Mo2O3I2(dtc)2 (THF)2 (1) + pyridine-N-oxide= 2MoO2I(dtc) + pyridine was investigated in methylene chloride solution using a variety of substituted pyridine-N-oxides. This is the first kinetics study of the reaction of an oxobridged Mo(V) complex participating in an oxo-transfer reaction. Reactions were studied using pseudo-first-order conditions of excess N-oxide. These reactions were characterized by saturation kinetics in which 1 reversibly forms a Mo2O34+-N-oxide precursor complex that generates products via irreversible breaking of an MoOb bond to give two equivalents of MoO22+ complex and the appropriate pyridine derivative. A considerable group effect was observed (two orders of magnitude) when substituents on the pyridine-N-oxides were varied, with electron releasing substituents slowing the rate of reaction. This observation is used to support a proposed mechanism by which the rate of MoOb bond breaking in the precursor complex is determined by the NO bond strength of the substrate N-oxide.
Baird, Donald M.; Aburri, C.; Barron, L. S.; and Rodriguez, S. A., "Mechanism of an Oxygen Atom Transfer Reaction Involving an Oxo-bridged Mo(V) Complex" (1995). Chemistry and Physics Faculty Articles. 9.