THE NU(1) BAND OF KETENE

Infrared and Raman spectra of the upsilon(1) band of ketene, H2CCO, ha ve been recorded at Doppler resolution. The infrared spectrum has been obtained with a difference frequency infrared spectrometer, and the R aman spectrum of the e branches of this band has been recorded using a stimulated Raman spectrometer. The vib-rotational analysis of the dat a is very complicated because of many crossings with other vibrational states, which can interact with upsilon(1)=1 through Fermi or Corioli s mechanisms. We present a discussion on global and local resonances, and we are able to extract information on the perturbing levels and on the perturbation parameters, even though the perturbing bands are not always detected in the spectrum.