ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Collisional removal rate constants for the OH(X 2Π, v=9) radical are measured for the colliders O2, CO2, and N2O and upper limits are established for He, H2, Ar, and N2. OH(v=6) molecules, generated in a microwave discharge flow cell by the reaction of hydrogen atoms with ozone, are excited to v=9 by the output of a pulsed infrared laser via direct vibrational overtone excitation. The temporal evolution of the v=9 population is probed as a function of the collider gas partial pressure by a time-delayed pulsed ultraviolet laser. The probe laser light is resonant with the B 2Σ+–X 2Π(0,9) transition and the resulting visible B 2Σ+–A 2Σ+ fluorescence is detected with a filtered photomultiplier tube. We measure rate constants for N2O: (6.4±1.0)×10−11; CO2: (5.7±0.6)×10−11; O2: (1.7±1.1)×10−11; H2: 〈3×10−12; He: 〈2×10−12; N2: 〈5×10−13; Ar: 〈2×10−13 (all in units of cm3 s−1). For O2 and CO2 these rate constants are significantly faster than those for low vibrational levels and comparable to those for v=12.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.465932
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