No abstract

The Edmiston-Ruedenberg (ER) and Boys localization methods are compared for a number of boron hydrides and carboranes. The Boys localization equations are solved explicitly for the two-orbital case and an iterative procedure for the multidimensional case is presented. The Boys analogs of Taylor's [J. Chem. Phys. 48, 2385 (1968)] ER equations are derived and the second-order term is converted into a symmetrized quadratic form which is analogous to the ER equations of Switkes et al. [J. Am. Chem. Soc. 92, 3847 (1970)]. A limited second-derivative test is employed in order to determine the nature of the convergence, and a transformation based on it is defined which successfully resolves structural ambiguities to which the standard two-orbital transformation procedure is subject. The Boys and ER localization methods are in at least qualitative agreement for all molecules except 1,2-C2B4H6, where the Boys localization yields a structure with fractional bonds and no open three-center B–C–B bonding. Previous ER localizations of 1,2-C2B4H6 resulted in two open B–C–B three-center bonds and no fractional bonding.

No abstract

No abstract

The oxidation of nitric oxide to N02 has been studied by trapping the products of the gas-phase reactions of nitric oxide with excess oxygen and ozone in argon matrices at 10 K. The subsequent transient species were identified and characterized by their infrared spectra. The primary products of the NO + 02 reactions were N02, N203(A), N203(B), N204, and peroxy nitrate (OONO). The primary products of the NO + 03 reactions were N02 and peroxy N03 with the higher nitric oxides (N203, N204,) formed in low concentrations relative to the NO + 02 reactions. Isotopic oxygen and ozone were employed to identify the infrared absorption frequency of peroxy nitrate. On the basis of our observations, reaction mechanisms are proposed for the oxidation of NO to N02.