Infrared Chemiluminescence Study of the Reaction of Hydroxyl Radical with Formamide and the Secondary Unimolecular Reaction of Chemically Activated Carbamic Acid
| Autor: | Donald W. Setser, N. I. Butkovskaya |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Formamide
010304 chemical physics Radical 010402 general chemistry Photochemistry 01 natural sciences Bond-dissociation energy 0104 chemical sciences law.invention chemistry.chemical_compound Ammonia Carbamic acid chemistry law 0103 physical sciences Molecule Hydroxyl radical Physical and Theoretical Chemistry Chemiluminescence |
| Zdroj: | The Journal of Physical Chemistry A. 122:3735-3746 |
| ISSN: | 1520-5215 1089-5639 |
| DOI: | 10.1021/acs.jpca.8b01512 |
| Popis: | 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 decompos... |
| Databáze: | OpenAIRE |
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