Water vapor enhancement of the HNO3 yield in the HO2 + NO reaction and its impact on the atmospheric composition

International audienceWater vapor enhancement of the HNO3 yield in the HO2 + NO reaction and its impact on the atmospheric compositio

Water vapor enhancement of the HNO3 yield in the HO2 + NO reaction and its impact on the atmospheric composition

International audienceWater vapor enhancement of the HNO3 yield in the HO2 + NO reaction and its impact on the atmospheric compositio

Water vapor enhancement of the HNO3 yield in the HO2 + NO reaction and its impact on the atmospheric composition

International audienceWater vapor enhancement of the HNO3 yield in the HO2 + NO reaction and its impact on the atmospheric compositio

Rate Constant and Mechanism of the Reaction of OH Radicals with Acetic Acid in the Temperature Range of 229−300 K

International audienc

Water vapor enhancement of the HNO3 yield in the HO2 + NO reaction and its impact on the atmospheric composition

International audienceWater vapor enhancement of the HNO3 yield in the HO2 + NO reaction and its impact on the atmospheric compositio

Formation of Nitric Acid in the Gas-Phase HO2 + NO Reaction: Effects of Temperature and Water Vapor

International audienc

Infrared Chemiluminescence Study of the Reaction of Hydroxyl Radical with Formamide and the Secondary Unimolecular Reaction of Chemically Activated Carbamic Acid

Reactions of OH and OD radicals with NH₂CHO and ND₂CHO were studied by Fourier transform infrared emission spectroscopy of the product molecules from a fast-flow reactor at 298 K. Vibrational distributions of the HOD and H₂O molecules from the primary reactions with the C–H bond were obtained by computer simulation of the emission spectra. The vibrational distributions resemble those for other direct H atom abstraction reactions, such as with acetaldehyde. The highest observed level gives an estimate of the C–H bond dissociation energy in formamide of 90.5 ± 1.3 kcal mol^–1. Observation of CO₂, ammonia, and secondary water chemiluminescence gave evidence that recombination of OH and NH₂CO forms carbamic acid (NH₂COOH) with excitation energy of 103 kcal mol^–1, which decomposes through two pathways forming either NH₃ + CO₂ or H₂O + HNCO. The branching fraction for ammonia formation was estimated to be 2–3 times larger than formation of water. This observation was confirmed by RRKM calculation of the decomposition rate constants. A new simulation method was developed to analyze infrared emission from NH₃, NH₂D, ND₂H, and ND₃. Dynamical aspects of the primary and secondary reactions are discussed based on the vibrational distributions of CO₂ and those of H/D isotopes of water and ammonia