Study of H+NO2 in an Argon Matrix between 4 and 14°K; The Infrared Spectra of Matrix-Isolated cis- and trans-HONO

Abstract

The matrix‐isolated infrared spectra of cis‐ and trans‐nitrous acid molecules have been obtained in argon at low temperatures by the reaction of H atoms with NO₂. The spectra, which include ¹⁵N‐ and ¹⁸O‐substituted molecules, are not complicated by the stabilization of the acid in the presence of large concentrations of NO, NO₂, and H₂O. All six fundamentals of the cis and three of the trans isomers have been identified, and found generally to confirm the assignments of a previous study where some uncertainty did exist. The normal coordinate calculation performed for the cis molecule predicted the average frequencies of the four ¹⁵N‐ and ¹⁸O‐substituted species with an error of 0.60 cm⁻¹ or 0.068%.