MATRIX REACTIONS OF OXYGEN ATOMS WITH P4. INFRARED SPECTRA OF P4O, P2O, PO and PO2

Author Institution: Department of Chemistry, University of VirginiaOxygen atoms (160 and 180) were reacted with P4 molecules using ozone photolysis and discharge of oxygen as sources, and the products were trapped in solid argon at 12K. The major product $P_{4}O$ exhibited a strong terminal $P=0$ stretching mode at $1241 cm^{-1}$, a $P-P=O$ deformation mode at $243 cm^{-1}$, and four P-P stretching modes near P4 values, all of which characterize a $C_{3v}$ species. Two new molecular species probably arise from energized P40 before relaxation by the matrix: the first absorbed at $1197 cm^{-1}$, photolysed with red light, and is probably $P_{2}O$; the second absorbed at 856 and $553 cm^{-1}$, increased with short wavelength radiation, and is most likely due to the $C_{2v}$ bridge-bonded $P_{4}O$ structural isomer. Higher discharge power gave 0 atoms and vacuum ultraviolet radiation; these conditions favored the bridge-bonded $P_{4}0$ species and the simple oxides PO and $PO_{2}$, which were observed at 1218 and $1319 cm^{-1}$, respectively. The matrix efficiently quenched the large exothermicity $(130 \pm 10 kcal/mole)$ for the $P_{4} + 0$ reaction and allowed the lowest oxide of phosphorus $P_{4}0$ to be trapped for the first time as a molecular species