15min:

V. BOUDON, Institut Carnot de Bourgogne, UMR 5209 CNRS--Université de Bourgogne, 9 Av. A. Savary, BP 47870, F-21078 Dijon Cedex, France; A. DOMANSKAYA, Institute of Physics, St. Petersburg University, 198504 St. Petersburg, Russia; C. MAUL, Institut für Physikalische und Theoretische Chemie der Technischen Universität Braunschweig, D-38106 Braunschweig, Germany; R. GEORGES, Institut de Physique de Rennes, UMR 6251 CNRS--UniversitŽ de Rennes 1, 263 Av. Général Leclerc, F-35042 Rennes Cedex, France; J. MITCHELL, University of Arkansas, 226 Physics Building, Fayetteville AR 72701, USA.

CF₄ is a strong greenhouse gas of both anthropogenic and natural origin\footnoteD. R. Worton, W. T. Sturges, L. K. Gohar et al.\/ , Environ. Sci. Technol.\/ 41, 2184--2189 (2007).. However, high-resolution infrared spectroscopy of this molecule has received only a limited interest up to now. The public databases only contain cross-sections for this species, but no detailed line list. We reinvestigate here the strongly absorbing ₃ region around 7.3 µm. Two new Fourier transform infrared spectra at a 0.003 cm^-1 resolution have been recorded: i) a room-temperature spectrum in a static cell with a 5 mb pressure and ii) a supersonic expansion jet spectrum at a 15 K estimated temperature. Following the work of Gabard et al.\/ \footnoteT. Gabard, G. Pierre and M. Takami, Mol. Phys. 85, 735--744 (1995).\labelgab, we perform a simultaneous analysis of both the ₃ and 2 ₄ bands since a strong Coriolis interaction occurs between them, perturbing the ₃ R-branch rotational clusters around J=20. As in Ref. \refgab, we also include ₃- ₃ microwave data in the fit. The analysis is performed thanks to the XTDS and SPVIEW programs. Compared to Ref. \refgab, the present work extends the analysis up to higher J values (56 instead of 32). Absorption intensities are estimated thanks to the dipole moment derivative value of D.~Papousek et al.\/ \footnoteD. Papousek, Z. Papousková and D. P. Chong, J. Phys. Chem.\/ 99, 15387--15395 (1995). and compare well with the experiment. The rotational energy surfaces for the ₃/2 ₄ dyad are also examined in order to understand the distribution of rovibrational levels.