The Infrared Spectroscopy and Photochemistry of NO3 Trapped in Solid Neon
Marilyn E. Jacox, Warren E. Thompson
NO3 can be stabilized in solid neon either by codeposition at 4.3 K of a Ne:O2 mixture with a Ne:NO mixture that had been passed through a microwave discharge or, in higher yield, by codeposition of a Ne:NO mixture with a Ne:O2 mixture, followed by annealing of the deposit at ca. 7 K and exposure of the solid to near ultraviolet radiation. All of the previously reported bands of NO3 between 700 cm-1 and 3000 cm-1 were observed, most with neon-matrix shifts of less than 2.5 cm-1. The infrared spectra of seven isotopic species of NO3 were obtained. The observed isotopic shifts demonstrate the occurrence of extensive mixing of ground-state levels of e' symmetry and their strong vibronic interaction with the B 2E' state, supporting a recently proposed reassignment of the v3 (e') fundamental of ground-state NO3. Photodissociation of NO3 by irradiation of the deposit at wavelengths longer than 520 nm leads to new absorptions near the fundamentals or NO and O2 and other new absorptions at relatively low frequencies. These absorptions were depleted and NO3 regenerated by subsequent near ultraviolet irradiation of the deposit, suggesting the stabilization of a weakly bound NO(O2) complex in solid neon.