J. d'Incan

Spectre Électronique de la Molécule LuH

Six new electronic band systems, assigned to LuH, have been excited between 5000 and 8000 A in a Lu2Cb–Th–Cu hollow cathode filled with argon and traces of hydrogen. The molecular constants and the nature of the electronic states of this molecule are derived from their rotational analysis.

The KRb electronic state

Abstract High-resolution spectra of the (3) 1 Π →(2) 1 Π system of the KRb molecule, obtained after excitation with fixed Ar+ laser frequencies, were recorded on a Connes-type Fourier transform interferometer. Our spectral observations led to the reassignment by 6 quanta of the vibrational numbering for the (2) 1 Π state reported by Kasahara et al. [J. Chem. Phys. 111 (1999) 8857]. Molecular constants of the first 19 vibrational levels of the (2) 1 Π state are determined by mixing the present work results and those of Kasahara et al. The potential energy curve is derived. The main spectroscopic constants for this highly perturbed electronic state of the 39 K 85 Rb isotopic species are: Te=15 902.06 (0.18) cm−1; ωe=49.76 (0.17) cm−1; Be=0.02438 (5) cm−1; Re=5.088 A; De=1358.19 (0.80) cm−1.

Etude d'une nouvelle transition électronique attribuée à l'ion CO+

Abstract A new electronic band system assigned to a 2 Δ r → A 2 Π i transition of the CO + ion has been observed under the action of a pulsed microwave discharge on a low pressure CO-Ne mixture. The different constants of 2 Δ r state have been determined using rotational analysis. An excitation mechanism of 2 Δ r state is proposed.

High-resolution Fourier spectrometry of 14N2 infrared emission spectrum: Analysis of the w1Δu-a1Πg system

Abstract The study by high-resolution Fourier Spectrometry of the w 1 Δ u - a 1 Π g system of N 2 allowed us to measure the absolute wavenumbers of rotational lines in the 0-0, 1-0, 2-1, 3-2 bands with a precision of 3.10 −3 cm −1 . Rotational analysis gave us very precise rotational parameters.

Etude thermodynamique de la flamme oxyacétylénique á partir du spectre de vibration-rotation de OH

The temperature of an oxyacetylene flame burning in air or in nitrogen has been determined from the (1, 0) band of the rotation-vibration spectrum of OH. The lines from quantum numbers K = 16 through K = 21 (3. 5 μ < λ < 3. 9 μ) have been measured. The distribution of the populations of OH radical was then deduced in the outer cone of the flame surrounded with nitrogen. A theoretical study of this latter flame has been realized from recent thermodynamic data, and the comparison of results concerning OH with those given by spectroscopic measurements shows that the thermal equilibrium is approximately attained.

Etude de la répartition des radicaux OH dans la flamme oxyacétylénique, à partir des spectres infrarouge et ultraviolet

Abstract The distribution of populations of the OH radical produced in an oxyacetylene flame has been determined from either emission intensities of the (1–0) band of the rotation-vibration spectrum or emission and absorption intensities of the (0-0) band of the 2 Σ- 2 Π system. Flat and conical burners, surrounded with air, nitrogen or oxygen sheaths, were used. Anomalies in the distribution of OH populations and in the flame temperature have been observed with the flat burner. This fact is ascribed to chemiluminescence.