HIGH-RESOLUTION INFRARED-SPECTRA OF FORMYL FLUORIDE, HFCO

Five fundamental infrared bands of HFCO have been studied at high resolution for the first time: nu5 (approximately 663 cm-1), nu6 (approximately 1011 cm-1), nu4 (approximately 1065 cm-1), nu3 (approximately 1342 cm-1), and nu1 (approximately 2981 cm-1). A Bomem Fourier transform spectrometer and an adjustable long-path cell were used. The effects of the strong a- and b-type Coriolis interactions between nu6 and nu4 were analyzed in detail, as was a weaker but still significant interaction between nu3 and nu5. On the other hand, perturbations noted in the nu1 band were not analyzed in detail because of the large number of possible interacting vibrational states in the 3000-cm-1 region. Thirteen of the 14 known far-infrared laser transitions of HFCO, resulting from optical pumping of nu4 and nu6 by CO2 lasers, were assigned in detail on the basis of the present analysis. (C) 1994 Academic Press, Inc.