HIGH RESOLUTION INFRARED SPECTROSCOPY OF THE PO$_2$ RADICAL

Abstract

The infrared absorption spectrum associated with the asymmetric stretching fundamental of PO$_2$ ($v_3$) has been measured using high resolution tunable diode laser spectroscopy. The free radical was formed in large concentrations in a fast-flow system by reacting white phosphorus vapour with atomic oxygen. More than 700 new lines have been assigned between 1290 and 1350 cm$^{-1}$. Data was combined with infrared and LMR lines, obtained from previous studies and simultaneously fitted using the CALPGM suite. The precise constants derived definitively exclude a series of unassigned transitions from belonging to the $v_3$ fundamental band and potential assignments for that series are discussed.