Absolute rate data for the collisional removal of Ge(4 3P 1) by olefins by time-resolved atomic resonance absorption spectroscopy

Abstract

We present a kinetic study of the collisional removal of atomic germanium, Ge(4 3P 1), with a range of olefins. This atomic state was generated by the repetitive pulsed irradiation of Ge(CH 3) 4 in the presence of excess helium buffer gas in a slow flow system, kinetically equivalent to a static system, and monitored in the time-resolved mode, on time scales by which Boltzmann equilibration within GE(4 3P J ) had taken place, at λ = 259.3 nm (Ge(5s( 3P 1)) ← Ge(4p 2( 3P 1)). A new body of absolute second-order rate constants, k R, for collisional removal by the olefins, R, are reported ( T = 300 K, errors = 2 σ): R k R (×10 −10 cm 3 molecule −1 s −1) Ethylene 1.2 ± 0.2 Propylene 1.8 ± 0.2 cis-Butene 1.0 ± 0.4 1-Pentene 1.5 ± 0.6 1-Hexene 1.3 ± 0.6 Cyclohexene 2.5 ± 0.4 Cycloheptene 2.5 ± 0.4 1,5-Cyclo-octadiene 3.6 ± 0.2 These data, representing collisional removal of atomic germanium with efficiencies of those of the order of the collision numbers, are compared with analogous absolute data for Si(3 3P j ).