A highly sensitive method for time-resolved detection of O(1D) applied to precise determination of absolute O(1D) reaction rate constants and O(3P) yields.
We demonstrate detection, in the gas-phase, of O(1D2) at concentrations down to 10(7) cm(-3) and develop this new method for time-resolved kinetic studies allowing both the total removal rate of O(1D2), of up to 1.5 x 10(6) s(-1), and the fraction quenched to O(3P(J)) by species X, k(q)/k(X), to be determined precisely from a single time profile: at 295 K we find, k(O(1D2) + N2O) = (1.43 +/- 0.08) x 10(-10) cm3 s(-1) with k(q)/k(N2O) = 0.056 +/- 0.009; k(O(1D2) + C2H2) = (3.1 +/- 0.2) x 10(-10) cm3 s(-1) with k(q)/k(C2H2) = 0.020 +/- 0.010; k(q)/k(H2O) < 0.003 for O(1D2) + H2O.
Carl
Shaun Avondale
SA
Department of Chemistry, University of Leuven, 200F Celestijnenlaan, 3001 Leuven, Belgium. shaun.carl@chem.kuleuven.be
D005030:Ethylenes / Q000737:chemistry; D008163:Luminescent Measurements / Q000379:methods; D009609:Nitrous Oxide / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry* / Q000528:radiation effects; D044367:Phase Transition; D010777:Photochemistry; D012680:Sensitivity and Specificity; D013816:Thermodynamics; D013997:Time Factors; D014466:Ultraviolet Rays; D014867:Water / Q000737:chemistry
D005030:Ethylenes; D014867:Water; C036216:ethylene; D009609:Nitrous Oxide; D010100:Oxygen