TRANSIENT EMITTING SPECIES IN PHOSPHORUS CHEMILUMINESCENCE

Abstract

Recently the emitting species in phosphorus chemiluminescence under ambient conditions have been identified as HPO, P0 $\gamma$-system and (PO)$_{2}^{*}$ $excimer.^{1}$ We have verified that the major visible emitting species is (PO)$_{2}^{*}$ excimer by observing the thermal dissociation of the excimer and the consequent appearance of the (0,0) transition of the PO $\beta$-system in the spectra. Further confirmation was given by diluting the system with a buffer gas affecting the equilibrium $(P0)_{2}^{*} \leftrightarrow PO(^{4}\Pi) + PO(X^{2}\Pi) \leftrightarrow PO(X^{2}\Pi) + PO(B^{2}\Sigma^{+}$) to enhance the PO $\beta$-system emission. Drying the reactants beforehand decreases the HPO emission without a major effect on the continuum emission, which eliminates the possibility that the continuum could arise from a species containing hydrogen.