Laser magnetic resonance spectroscopy of ClO and kinetic studies of the reactions of ClO with NO and NO₂

Abstract

Abstract Far‐infrared rotational transitions in ClO(X 2 ∏ 3/2 , υ = 0) have been observed using laser magnetic resonance (LMR) with an optically pumped spectrometer. Five observed transitions at wavelengths between 444 and 713 µm have been compared with values predicted with spectroscopic constants from the literature. LMR detection of ClO has been used to study its reactions with NO and NO 2 in a discharge flow system under pseudo‐first‐order conditions for ClO. The measured rate constants are k (ClO + NO) = (7.1 ± 1.4) × 10 −12 exp[(270 ± 50)/ T ] cm 3 /molec·s for the temperature range of 202 < T < 393 K; k (ClO + NO 2 + M) = (2.8 ± 0.6) × 10 −33 exp[(1090 ± 80)/ T ] cm 6 /molec 2 ·s (M = He, 250 < T < 387 K), (3.5 ± 0.6) × 10 −33 exp[(1180 ± 80)/ T ] (M = O 2 , 250 < T < 416 K), and (2.09 ± 0.3) × 10 −31 (M = N 2 , T = 297 K). All measurements were made at low pressures, between 0.6 and 6.6 torr. These results are compared with those from other studies.