CHEMILUMINESCENT PATHWAYS IN REACTIONS OF PHOSPHORUS, ANTIMONY, AND BISMUTH WITH OZONE TO FORM DIOXIDES AND MONOXIDES

Chemiluminescent (CL) reactions have been observed using molecular bea ms of phosphorus, antimony, and bismuth colliding with ozone as a scat tering gas. The fluorescence spectra indicate the formation of electro nically excited PO2, SbO2, and BiO2, and probably SbO and BiO, as well . None of the emitting states of the dioxides seem to correspond to pr eviously characterized states. Since the beam source could generate va riable ratios of atoms, dimers, and tetramers, the CL reactions can be attributed to P, Sb, Sb-2, and Pi. The assignments of reactant specie s were aided by measurements of the total CL dependence on the beam ti me dependence. The time-dependent experiments also revealed CL reactio ns of antimony and bismuth, which are second order in ozone. Fits to t he time-dependent spectra show that whereas the first-order CL reactio n of P proceeds without a potential barrier, for Sb-n and Pi, only the second-order CL reactions can occur without very high barriers. (C) 1 998 American Institute of Physics.