The emission spectrum of the CO2+ ion: rovibronic analysis of the band system

Abstract

The Renner–Teller structure of the [Formula: see text] and Ã2Πu states of the CO2+ ion has been studied thanks to the identification and rotational analysis of the vibronic bands of the [Formula: see text] and [Formula: see text] systems, associated with the first quantum of the bending vibration in the [Formula: see text], Ã, and [Formula: see text] states. The bending structure of the à state has been understood and the corresponding parameters ω2 and ε have been determined for the first time. The simultaneous analysis of the 12CO2+ and 13CO2+ appropriate bands has led us to revise our earlier value of the Renner parameter for the [Formula: see text] state, derived from the [Formula: see text] system. In addition, three bands of the main progression ν′00–000 (ν′ = 0, 1, and 2) have been reanalyzed in order to obtain a consistent set of molecular parameters. The main molecular constants (in cm−1; r0 in Å) are summarized below for 12CO2+:[Formula: see text]The accurate experimental data derived from the CO2+ spectrum are discussed in the framework of the most recent theoretical models of the rovibronic structure of linear triatomic molecules.