Knowledge Bank

Oxygen 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 $P4O$ exhibited a strong terminal $P=0$ stretching mode at $1241cm-1$, a $P-P=O$ deformation mode at $243cm-1$, and four P-P stretching modes near P4 values, all of which characterize a $C3v$ species. Two new molecular species probably arise from energized P40 before relaxation by the matrix: the first absorbed at $1197cm-1$, photolysed with red light, and is probably $P2O$; the second absorbed at 856 and $553cm-1$, increased with short wavelength radiation, and is most likely due to the $C2v$ bridge-bonded $P4O$ structural isomer. Higher discharge power gave 0 atoms and vacuum ultraviolet radiation; these conditions favored the bridge-bonded $P40$ species and the simple oxides PO and $PO2$, which were observed at 1218 and $1319cm-1$, respectively. The matrix efficiently quenched the large exothermicity $(130\pm 10kcal/mole)$ for the $P4+0$ reaction and allowed the lowest oxide of phosphorus $P40$ to be trapped for the first time as a molecular species.