Potential Visible Chemical Lasers via Interactions of Singlet Molecular Oxygen with Heavy Metal Atoms and Oxides.

The present research has been the first part of a continued effort to thoroughly study the kinetics and spectroscopy of the heavy-atoms/singlet oxygen mixtures. The measurements were conducted in a flowing afterflow reactor to which a metal evaporation furnace and a singlet oxygen generator are interfaced. The atoms studied so far were Pb and Bi. The results of the measurements show that significant electronic excitation of metal atoms, metal dimers and metal oxides can be obtained via multiple collisions with singlet molecular oxygen. Laser induced fluorescence measurements in Pb/O2 mixtures corroborate the mechanism for PbO formation previously suggested in this laboratory. Mechanisms for production of excited species in Bi/O2 are inferred from the dependence of the emission intensity from these species in Bi/02 are inferred from the dependence of the emission intensity from these species on (Bi) and (Bi2). In particular, it is suggested that the strong emission from Bi(2D3/2) must originate from energy transfer from O2(I sigma) which, in turn, is produced via multiple collisions of O2(I delta) with Bi2. The results of the present research are encouraging regarding the prospects of obtaining significant concentrations of atomic and molecular species via multiple collision with singlet molecular oxygen. (Author)