Fourier transform spectroscopy of 12C18O2 and 16O12C18O in the 3800-8500 cm−1 region and the global modeling of the absorption spectrum of 12C18O2

The absorption spectrum of the 18O enriched carbon dioxide has been recorded at Doppler limited resolution with a Fourier transform spectrometer in the spectral range 3800-8500 cm−1. Seventeen cold bands (14Σ-Σ and 3Σ-Π) and nine hot bands (9Π-Π) of 12C18O2, nineteen cold bands (18Σ-Σ and 1Σ-Π) and eighteen hot bands (6Σ-Σ, 9Π-Π and 3Δ-Δ) of 16O12C18O have been observed. Among them, 14 12C18O2 bands and 12 16O12C18O bands are observed for the first time. The spectroscopic parameters Gv, Bv, and centrifugal distortion constants, have been determined for all observed bands. Effective Hamiltonian parameters for the 12C18O2 isotopic species are retrieved from the global fitting of the observed line positions presented in this paper and collected from the literature. As the result, 65 obtained effective Hamiltonian parameters reproduce 5443 observed line positions of 73 12C18O2 bands with RMS = 0.00145 cm−1.