Detection of the infrared laser spectrum of the PO2 radical in the gas phase

The infrared laser absorption spectrum of the PO2 free radical has been detected in the reaction of oxygen atoms with white phosphorus. Over 300 lines of the ν3 fundamental band of the 2A1 ground state have been measured and assigned between 1300 and 1345 cm−1. Rotational, centrifugal distortion and spin-rotation constants for the ν3 = 1 level have been obtained from fitting the lines to an asymmetric rotor Hamiltonian, with the ground state constants held at their microwave/laser magnetic resonance values. The band origin is 1327.53452(69) cm−1.