Answers are grounded in this paper and cite their sources.
Investigates photodissociation dynamics in atmospheric conditions, suggesting strong reaction pathways.
High Resolution Image Download MS PowerPoint Slide The photodissociation dynamics of peroxynitric acid (HO 2 NO 2 ) in the atmospherically relevant ultraviolet region are investigated using the complete active space SCF electronic structure calculations combined with nonadiabatic molecular dynamics based on the fewest-switches surface hopping method. Minimum-energy crossing points between the lowest two singlets and between the lowest two triplet states are characterized and classified according to their local topological features in the branching plane. The S 0 /S 1 crossing is identified as a sloped single-path intersection, whereas the T 1 /T 2 crossing exhibits a peaked bifurcating topology. Nonadiabatic dynamics simulations for the photodissociation of HO 2 NO 2 reveal ultrafast S 1 → S 0 relaxation mediated by the sloped intersection and a dominant NO 2 + HO 2 dissociation channel, with limited triplet involvement due to weak spin–orbit coupling. The predicted strong preference for the NO 2 + HO 2 pathway is consistent with updated experimental photolysis measurements in the actinic UV region, and the calculated rotational constants of HO 2 NO 2 show very good agreement with available spectroscopic data. These results elucidate how changes in excited-state molecular geometry govern the photodissociation behavior of HO 2 NO 2, highlighting the structural origin of its dominant reaction pathway.
No takes yet. Share an insight, caveat, or question.
Peng et al. (2026) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: