Vibrational energy transfer in laser-excited carbonic difluoride. Infrared fluorescence from the intermediate mode .nu.4

Abstract

quasicontinuum") are less important at least up to n = 5 than direct twoor three-photon transitions. The evidence was as follows: (1) excitation by P10 or P16, where the first step has to be a two-photon transition, generates similar effects as observed at other wavelengths in flash spectroscopy; (2) the dissociation yield strongly depends at all investigated wavelengths on the laser intensity, indeed stronger than expected for an explanation invoking hole burning in the rotational contour; (3) the carbon isotope selectivity around P40 is determined by a bottleneck which apparently consists for 13CF3I in a direct two-photon transition in the first step and for 12CF3I in a (more difficult) direct three-photon transition in the third step. It would, however, be harder to understand why absorption to the background states (quasicontinuum) should be more difficult in the third step in 12CF3I than in the first step for 13CF3I.Thus, indirect evidence indicates the nature of the bottleneck transitions, up to the fifth photon. It is desirable, however, to observe these and higher states directly. This would be feasible with improved sensitivity of flash spectroscopy.Acknowledgment. I thank J. Hartmann for his expert assistance in setting up and performing the experiment, and K. L. Kompa for his support and discussions.

van der Waals Complexes between Carbonyl Fluoride and Boron Trifluoride Observed in Liquefied Argon, Krypton, and Nitrogen: A FTIR and ab Initio Study

“…Intermolecular interactions involving carbonyl fluoride are of interest since this compound is believed to be one of the intermediates in the photodecomposition of chlorofluorocarbons in the stratosphere. , Another motivation of the study is that COF 2 is often observed in matrix-isolation infrared experiments as a product of photolysis of various fluorine-containing compounds. − Since the formation of COF 2 is sometimes accompanied by its complexation, , knowledge of structures and energies of plausible complexes is important for interpreting the observed spectra. In addition, it may be noted that COF 2 is one of the simplest asymmetric top molecules which has been widely used for testing various theoretical models of vibrational spectroscopy. − It appears interesting to correlate the complexation effect on vibrational spectra with some of the theoretical predictions.…”

“…In addition, it may be noted that COF 2 is one of the simplest asymmetric top molecules which has been widely used for testing various theoretical models of vibrational spectroscopy. [24][25][26][27][28] It appears interesting to correlate the com- plexation effect on vibrational spectra with some of the theoretical predictions.…”