The v4 = 1 and v4 = 2 rovibrational levels of PF3 revisited: New solutions for old topics

0453600 - ÚFCH JH 2016 RIV US eng J - Článek v odborném periodiku
Ceausu-Velcescu, A. - Pracna, Petr - Breidung, J. - Thiel, W. - Badaoui, M.
The v4 = 1 and v4 = 2 rovibrational levels of PF3 revisited: New solutions for old topics.
Journal of Molecular Spectroscopy. Roč. 316, OCT 2015 (2015), s. 11-21. ISSN 0022-2852. E-ISSN 1096-083X
Institucionální podpora: RVO:61388955
Klíčová slova: Phosphorus trifluoride * High-resolution IR spectroscopy * Hot bands
Kód oboru RIV: CF - Fyzikální chemie a teoretická chemie
Impakt faktor: 1.593, rok: 2015

The high-resolution infrared spectra of trifluorophosphine (PF3) were reinvestigated in the ν4 fundamental region near 350 cm−1, and around 690 cm−1, with the aim to provide a necessary reassignment of the 2±2 sublevel of the v4 = 2 overtone level. The present paper reports on the first complete study of both sublevels of v4 = 2 (of A1 and E symmetry, corresponding to l4 = 0 and ±2, respectively), through the high-resolution analysis of the overtone View the MathML source2ν40 band and the View the MathML source2ν4±2-ν4±1 hot band. The assignments of the latter were corrected and extended, spanning the rotational states J <= 82 and −80 <= K´´ · ΔK <= 48. These new infrared assignments in the v4 = 2 state were combined with accurate infrared, radiofrequency, centimeter-, millimeter- and submillimeter-wave data of the v4 = 1 level (Thiessen et al., 2000), together with rotational data in the ground vibrational state (Cotti et al., 1995), in a simultaneous fit. The existence of resonance crossings due to a Δk = ±1, Δl = ±2 l-type resonance in the v4 = 1 state, which generated perturbation-allowed transitions, provided independent values of the C4 and Cζ4 constants. Combining these rotational transitions with the wavenumbers of the ν4 fundamental band enabled us to determine accurately the C0 axial ground state constant. Moreover, the assignment of a few, very weak rRK transitions in the View the MathML source2ν4-2 overtone band and their inclusion in the global least-squares fit allowed also the first accurate experimental determination of View the MathML sourceDK0. The obtained results are (in cm−1): C0 = 0.159970241(29) and View the MathML sourceDK0=1.80457(49) × 10−7.



Trvalý link: http://hdl.handle.net/11104/0254369