First observations and analyses of the fourth-positive (A1Π → X1Σ+) band system in 14C16O

Abstract

In the isotopic 14C16O molecule eight bands of the fourth-positive (A1Π→X1Σ+) system were investigated for the first time. Under high resolution, using conventional photographic emission spectroscopy technique, highly excited 7–19, 8–20, 9–21, 10–21, 11–22, 12–23, 12–24 and 13–24 bands were recorded and spectroscopically analyzed. First individual constants of the rovibronic structure: Bv′ and Dv′ of both A1Π and X1Σ+ states as well as the equilibrium constants: Be, αe, γe, ωe, ωexe, and ωeye of the upper A1Π state were obtained. First values of band origins for all studied bands were also computed. On the basis of these parameters and the ground X1Σ+ state constants recalculated isotopically from Le Floch [1] spectroscopic constants, the first experimental rovibronic term values of the A1Π state vA=7–13 levels were calculated. Numerous observed rotational perturbations of the A1Π state were identified and compared with the theoretically determined ones.