15min:

A. PERRIN, M. CARVAJAL-ZAERA, Z. DUTKIEWICZ, Laboratoire de Photophysique Moléculaire, CNRS, Université Paris Sud, Campus d'Orsay, Bat 350, 91405 Orsay Cedex, France; J.-M. FLAUD, Laboratoire Interuniversitaire des Systemes Atmosphériques (LISA), CNRS, Université Paris 12, Bat. P1 61, avenue du Général de Gaulle 94010 Créteil Cedex, France; H. BÜRGER, D. COLLET, Anorganische Chemie, FB 9, Universität-Gesamthochschule, D-42097 Wuppertal, Germany; J. DEMAISON, F. WILLAERT, Laboratoire PhLAM, CNRS, Université de Lille I, Bat. P5, 59655 Villeneuve d'Ascq Cedex, France; H. MÄDER, Institut für Physikalische Chemie, Olshausenstrasse 40, D-24098 Kiel, Germany; N. W. LARSEN, Chemical Laboratory 5, H.C. Oersted Institute, 2100 Copenhagen, Denmark.

High resolution ( 2-3 x 10^-3 cm^-1) Fourier transform infrared spectra of gas phase ¹⁰B and ¹¹B enriched isotopic and natural samples of BF₂OH (difluoroboric acid) were recorded in the 400- 4000 cm^-1 spectral range. Starting from the results of a previous study which involved the ₈ (BF₂ out-of-plane bending) and ₉ (OH torsion) bands of ¹¹BF₂OH, it has been possible to perform the first rovibrational analysis of the ₅ (BF₂ bending), ₈, ₉ and ₈+ ₉ bands of ¹⁰BF₂OH, and of the ₅, ₇ (F₂BO in-plane bending) and ₈+ ₉ bands of ¹¹BF₂OH up to very high rotational quantum numbers. In addition microwave transitions within the 5¹, 6¹, 7¹, 8¹ and 9¹ vibrational states of ¹¹BF₂OH were measured using predictions performed from ab initio calculations. For the ₅ and ₇ bands of ¹¹BF₂OH, C-type Coriolis resonances coupling the 5¹ and 7¹ energy levels with those of the 7² and 6¹ dark states respectively were accounted for in the calculations. The other bands appeared to be unperturbed,