Microwave spectrum, structure, low frequency vibrations, dipole moment and quadrupole coupling constants of dinitrogen trioxide

Abstract

The structure of N₂O₃ has been determined from the microwave spectrum of seven isotopic species. The detailed structure associated with the following planar configuration is: [graphic omitted] d(N₂N₃)= 1.864 Å; d(N₂O₁)= 1.142 Å; d(N₃O₄)= 1.202 Å; d(N₃O₅)= 1.217 Å; ∠O₁N₂N₃= 105.1°∠O₄N₃N₂= 112.7°∠O₅N₃N₂= 117.5°. The torsional vibrational frequency has been measured as 124 ± 25 cm^–1. The quadrupole coupling constants for the nitrosyl nitrogen are χ_aa=–2.34 MHz, χ_bb= 1.12 MHz, and χ_cc= 1.22 MHz. The dipole moment has been determined as |µ_a|= 2.05 D; |µ_b|= 0.54 D; and |µ_t|= 2.12 D inclined at an angle of 9.1° to the N—N bond. On the basis of these data, the bonding is discussed.