Vibrational band oscillator strengths and dipole transition moment of the A 1Π–X 1Σ+ system of CO

Rotationally integrated vibrational absorption cross sections of the A 1Π−X 1Σ+ (v′−0) bands of CO have been measured in the wavelength range 125–155 nm using monochromatized synchrotron radiation as background light source. Absorption cross sections for a few singlet-triplet transitions are also obtained. Vibrational band oscillator strengths are determined for 0≤v′≤12 and compared to other experimental and theoretical values. It is found that the new data are well reproduced by extrapolating to shorter internuclear distances the parabolic dipole transition moment function determined by De Leon [J. Chem. Phys. 89, 20 (1988); 91, 5859 (1989)]. Deperturbed lifetimes for levels 0≤v′≤13 are calculated from the parabolic dipole moment function and, except for v′=13, are found in good agreement with available experimental results.