ISSN:
1434-1948
Keywords:
Ab initio calculations
;
Mass spectrometry
;
Gas-phase chemistry
;
Ammonia oxide
;
Hydroxylamine
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Mass-spectrometric experiments were combined with ab initio calculations to explore the cationic and neutral [H3,N,O]⋆+/0 potential energy surfaces and relevant anionic species. The calculations predict the existence of three stable cationic and neutral [H3,N,O]⋆+/0 isomers, i.e. ammonia oxide H3NO⋆+/0 (1⋆+/0), hydroxylamine H2NOH⋆+/0 (2⋆+/0) and the imine-water complex HNOH2⋆+/0 (3⋆+/0). Hydroxylamine 2 represents the most stable isomer on the neutral surface (Erel = 0), and the metastable isomers 1 (Erel = 24.8 kcal mol-1) and 3 (Erel = 61.4 kcal mol-1) are separated by barriers of 49.5 kcal mol-1 and 64.2 kcal mol-1, respectively. Adiabatic ionization of 2 (IEa = 9.15 eV) yields 2⋆+, which is 21.4 kcal mol-1 more stable than 1⋆+ and 36.4 kcal mol-1 more stable than 3⋆+. The barriers associated with the isomerizations of the cations are 58.6 kcal mol-1 for 2⋆+ → 1⋆+ and 71.4 kcal mol-1 for 2⋆+ → 3⋆+. Collisional activation (CA) and unimolecular decomposition (MI) experiments allow for a clear distinction of 1⋆+ from 2⋆+. Besides, neutralization/reionization (NR) experiments strongly support the gas-phase existence of the long-sought neutral ammonia oxide.
Type of Medium:
Electronic Resource
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