C3O - ABINITIO CALCULATIONS AND MATRIX IR-SPECTRA

The equilibrium geometry of linear C3O has been calculated with high precision (almost-equal-to 0.0005 angstrom accuracy) by combining experimental ground-state rotational constants and theoretical vibration-rotation coupling constants. The results are R1e (C1-C2) = 1.2717 angstrom, R2e (C2-C3) = 1.2965 angstrom and R3e (C3-O) = 1.1473 angstrom. New matrix IR spectra show a larger number of peaks not observed before which are assigned to overtones and combination tones. In addition, the very weak v3 fundamental was found at 939.1 cm-1. Its intensity is much smaller than that of the corresponding first overtone as theoretically predicted earlier by one of us.