Rate constant for the reaction of PO radical with oxygen

Abstract

A CO2 TEA laser is used to generate PO radical by infrared multiphoton dissociation of dimethyl methylphosphonate in an excess of oxygen at total pressures up to 1.4 Torr. The pseudo-first-order reactive decay of PO (v″=0) is followed by laser-induced fluorescence utilizing its A 2Σ+–X 2Π transition. A bimolecular rate constant of 1.4 (±0.2)×10−11 cc/molecule/s is measured for the PO+O2 reaction. Earlier measurements of a much slower rate in flow discharge systems may be complicated by the establishment of equilibrium between the forward and reverse reactions PO+O2↔PO2+O.