Collisional quenching of electronically excited germanium atoms, Ge(4p 2( 1D 2)), by unsaturated ring compounds determined by time-resolved atomic resonance absorption spectroscopy in the ultra-violet

Abstract

The collisional quenching of the optically metastable, electronically excited germanium atom, Ge(4p 2( 1D 2)) (0.883 eV), by unsaturated ring compounds has been investigated by time-resolved atomic resonance absorption spectroscopy in the ultra-violet at λ = 241.737 nm Ge(4d( 1D 2°)) ← (4p 2( 1D 2))) following the pulsed irradiation (λ > ca. 160 nm) of Ge(CH 3) 4 in the presence of excess helium gas and the added reactant gases. The 1D 2 atom was generated in a slow flow system, kinetically equivalent to a static system and monitored photoelectrically using direct computer interfacing for data capture and analysis as described hitherto. Collisional quenching proceeds rapidly in all cases and the resulting new body of rate data are compared in general terms with absolute second-order rate constants for the removal of Ge(4 1D 2) by simple molecules and unsaturated hydrocarbons investigated hitherto and, where available, with data for the removal of the ground state Ge(4 3P j) and Si(3 3P j) atoms with similar species.