No abstract

Matrix-isolated (NO)2 has been obtained by rapid deposition of NO–N2 mixtures on an optical window at 15°K, by limited diffusion of matrix-isolated NO at low temperatures, and by photochemical production of O atoms in an N2O environment. Controlled low-temperature studies allowing limited molecular diffusion indicate spectral growth patterns due to three different species. Experiments carried out with 15NO and N18O isotopic samples along with the photochemical production of (NO)2 suggests that cis and trans O=N=N=O and possibly another unstable cis form are produced.

The infrared spectra of four isotopic species of matrix−isolated nitric acid have been obtained. The vibrational assignments are in general agreement with previous gas and condensed phase observations with the exception of those assigned to the NO2 valence bend and NO′ single bond stretch. The results of diffusion experiments performed indicate that nitric acid may form cyclic dimers similar to the carboxylic acids.

The vacuum-ultraviolet photolysis of germane and the four deuterogermanes isolated in an argon matrix at temperatures between 4 and 25°K produces significant concentrations of several reactive species. Absorptions at 1839, 1813, 928, and 850 cm−1 have been assigned to a pyramidal GeH3 molecule and those at 1887, 1864, and 920 cm−1 have been assigned to a nonlinear GeH2 molecule. Digermane and the products of its photolysis are also produced and contribute considerably to the infrared spectra in the region below 1000 cm−1.

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%.