ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Electronic quenching of IF B 3Π(0+) was studied in a time resolved laser fluorescence experiment. IF (B) deactivation rate constants were determined as a function of vibrational quantum number for the following collision partners: He, Ne, Ar, Kr, Xe, N2, F2, I2, O2, and H2O. Quenching by the noble gases and N2 was extremely slow with all rate constants less than 1×10−14 cm3 molecule−1 s−1 for 3≤v'≤8. The quenching rate constants for F2 showed a weak dependence on vibrational quantum number, ranging from (3.4±0.5)×10−12 to (5.2±0.4)×10−12 cm3 molecule−1 s−1 for v'=3 and v'=7, respectively. Double exponential IF (B) fluorescence decays were observed with both O2 and H2O indicating two depletion processes occurring over the lifetime of IF (B). The quenching rate constants, extracted from the decays at long times, were (1.4±0.2)×10−12 cm3 molecule−1 s−1 for O2 and (7.6±1.6)×10−12 cm3 molecule−1 s−1 for H2O. At early times, the respective deactivation rate constants for O2 and H2O were (8.3±1.4)×10−12 and (2.4±0.7)×10−10 cm3 molecule−1 s−1. A possible quenching mechanism by O2 is discussed. The most efficient quencher was I2 with an estimated rate constant of 3.9×10−10 cm3 molecule−1 s−1.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.449743
