Overtone Transitions of 12CO2 beyond the Venus Bands

Combination overtone transitions of 12CO2 much weaker than the Venus bands in the near infrared (11 700-14 200 cm-1) have been observed for the first time by using photoacoustic spectroscopy. A total of six bands from two Fermi polyad groups were recorded and both the band origins and relative intensities have been determined and compared with the calculated values. Through a comparison of the relative absorption cross sections within the same type of polyads, intensity shifts have been observed and will be discussed. Copyright 1999 Academic Press.