Absolute intensities in the nu(1), 2 nu(2), 2 nu(3)+nu(4) band system of carbonyl fluoride

The IR spectrum of carbonyl fluoride, COF2, has been measured in the region 1880-1980 cm(-1) using a Bomem Fourier transform spectrometer under 0.005 cm(-1) resolution at a gas pressure of 3.2 Torr, 10 cm pathlength and at room-and stratospheric (ca. 200 K) temperatures. In this region the v(1) band at 1945 cm(-1) dominates the spectrum and is in Fermi resonance with the weaker 2v(2) band at 1914 cm(-1), and in B-type Coriolis resonance with the 2v(3) + v(4) band at 1936 cm(-1). The absorption coefficients of this band system have been determined from the experimental spectra and the integrated intensity in this region is found to be 3.07 x 10(-17) cm molecule(-1) at room temperature and 3.26 x 10(-17) cm molecule(-1) at ca. 200 K. Using calculated spectra the integrated intensities were predicted to be 2.90 x 10(-17) cm molecule(-1) and 3.01 x 10(-17) cm molecule(-1), respectively using transition dipole moments of 0.1592 D for v(1) and 0.1097 D for 2v(2).dagger The small discrepancy in integrated intensity can be accounted for from thermally populated states, whose contribution was not calculated.