SPECTRES DE VIBRATION-ROTATION DE MOLECULES SIMPLES DIATOMIQUES OU POLYATOMIQUES AVEC LONG PARCOURS D'ABSORPTION: XII. LE SPECTRE DE C12O162 ENTRE 3500 ET 8000 CM−1 ET LES CONSTANTES MOLECULAIRES DE CETTE MOLECULE

Abstract

Numerous absorption bands of the molecule C12O162 have been obtained in the near infrared under high resolution with the help of a multiple path absorption cell. Of these bands, 27 have been analyzed, among them three Δ—Δ transitions.The usual formula for the vibrational levels has been extended to include cubic terms and the values of the vibrational constants are given. Similarly the rotational constants Bν have been expressed by a formula including quadratic terms and the constants in this formula are given. The values of B0 and Be obtained here are respectively 0.39021 ±.00004 and 0.39162 cm−1.The l-type doubling constant qν of the Π states (apart from effects of Fermi resonance) can be represented by[Formula: see text].The perturbation term of the Fermi resonance is given by the expression[Formula: see text],where the quantum number l does not enter the first factor. The introduction of this expression allows one to represent all the vibrational levels as well as the rotational constants of each level and the constant q of the Π states with excellent precision.The value of D0 is found to be 13.5 × 10−8 cm−1. The effect of the Fermi resonance and of the perturbation between levels (ν1, ν2, l, ν3) and (ν1, ν2, l ± 2, ν3) on the constants D is discussed. The experimental values for these constants agree in a very satisfactory way with those calculated by Amat, Goldsmith, and Nielsen as do the constants μ of l-type doubling of the Π states.Finally the effect of Coriolis perturbation between the levels 3200 and (0511)c is demonstrated.