Abstract book - Prof. Per Jensen, Ph.D. - Bergische Universität ...

Poster session, H44 157A High Resolution FTIR Spectroscopic Study of Collisional - CooledCHF 3 : Re-Analysis of the Strongly Coupled States v 2 , v 5 , and v 3 +v 6A O. N. Ulenikov 1,2 , E. S. Bekhtereva 1,2 , I. B. Bolotova 1 , S. Albert 1 ,S. Bauerecker 1,3 , H. Hollenstein 1 , and M. Quack 11 Physical Chemistry Laboratory, ETH-Zürich, CH-8093, Zürich, Switzerland; 2 TomskState University, Physics Department, 634050, Tomsk, Russia; 3 Technische UniversitätBraunschweig, D - 38106, Braunschweig, GermanyUlenikov O.N.Bekhtereva E.S.Bolotova I.B.Albert S.Bauerecker S.Hollenstein H.Quack M.The infrared spectrum of CHF 3 is a prototypical spectrum of a classical symmetric topmolecule. Despite a long history 1-8 its rotationally resolved infrared spectrum is poorlyunderstood due to numerous strong interactions. For that reason we have started toreinvestigate the IR spectrum of CHF 3 . In this paper we present an analysis of the stronglycoupled triad of the states v 2 , v 5 , and v 3 +v 6 previously measured and analyzed using FTIRsupersonic jet spectroscopy. 5The high resolution FTIR spectrum of CHF 3 has been measured with the Bruker 125 HRspectrometer using a collisional cooling cell 9 in the regions 1000-3600 and 5800-6800 cm -1at two different temperatures, 120 and 295 K. As the result of analysis of the experimentaldata, transitions with maximum values of the quantum numbers J and K larger than 80 wereassigned to all the bands, v 2 , v 5 , and v 3 +v 6 , that is considerably more transitions than inprevious studies.In our present analysis we start by theoretical estimates of various parameters on the basis ofa known ab initio intramolecular potential function 6 . The equations, which connect the mostimportant interaction parameters with the parameters of the potential function, have beenderived on the basis of operator perturbation theory. This information was used in the fit ofexperimental upper energy levels obtained from the assignment of transitions in theexperimental spectrum. The fit results in a set of parameters which reproduce the initialexperimental data with an accuracy close to the experimental uncertainties.References[1] H. R. Dübal and M. Quack, Chem. Phys. Lett., 80, 439 - 444, 1981.[2] H. R. Dübal and M. Quack, J. Chem. Phys., 81, 3779 - 3791, 1984.[3] G. Graner, and G. Guelachvili, J. Mol. Spectrosc., 107, 215 - 228, 1984.[4] J. P. Champion, and G. Graner, Mol. Phys, 58, 475 - 484, 1986.[5] A. Amrein, M. Quack, and U. Schmitt, Mol. Phys., 60, 237 - 248, 1987.[6] J. Breidung, J. Cosleou, J. Demaison, K. Sarka, and W. Thiel, Mol. Phys., 102,1827 - 1841, 2004.[7] A. Amrein, M. Quack, and U. Schmitt, J. Phys. Chem., 92, 5455 - 5466, 1988.[8] S. Albert, K. Keppler Albert, H. Hollenstein, C. Manca Tanner, and M. Quack inHandbook of High Resolution Spectroscopy, Vol. 1,M. Quack and F. Merkt eds.,Wiley Chichester 2011.[9] S. Albert, S. Bauerecker, M. Quack, and A. Steinlin, Mol. Phys., 105, 541 - 558, 2007.