High-resolution infrared and microwave study of 10BF2 OH and 11BF2OH: the 5, 6l, 71, 8l, 91 and 81 91 vibrationally excited states

• Published in: Molecular physics Vol. 102; no. 14-15; pp. 1641 - 1652
• Main Authors: Perrin, A., Carvajal-Zaera, M., Dutkiewicz, Z., Flaud, J.-M., Collet, D., Burger, H., Demaison, J., Willaert, F., Mäder, H., Larsen, N. W.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01-08-2004
• ISSN: 0026-8976; 1362-3028
• DOI: 10.1080/00268970410001725756

High-resolution (≤2.4×10
−3
cm
−1
) Fourier transform infrared spectra of gas-phase
10
B-enriched isotopic and natural samples of BF
2
OH (difluoroboric acid) were recorded in the 400-4000 cm
−1
spectral range. Starting from the results of a previous study [Collet, D., Perrin, A., Burger, H., and Flaud, J.-M., 2002, J. Molec. Spectrosc. 212, 118], which involved the v
8
10
BF
2
out-of-plane bending) and v
9
(OH torsion) bands of
11
BF
2
OH, it has been possible to perform the first rovibrational analysis of the v
5
10
BF
2
bending), v
8
, v
9
and v
8
+v
9
bands of'
11
BF
2
OH, and of the v
7
(F
2
BO in-plane bending), v
5
, and v
8
+v
9
bands of
11
BF
2
OH up to very high rotational quantum numbers. In addition, microwave transitions within the 5
1
, 6
1
, 7
1
and 8
1
vibrational states of
11
BF
2
OH were measured using predictions from ab initio calculations [Breidung, J., Demaison, J., D'Eu, J.-F., Margules, L., Collet, D., Mkadmi, E. B., Perrtn, A., And Thiel, W., 2004, J. Mol. S ectrosc. (in press)]. The v
5
, v
8
, v
9
and v
8
+v
9
bands of' bands of
10
BF
2
OH and the v
8
+v
9
band of'BF
2
OH are not significantly affected by ptrturbations, and the experimental 5
1
, 8
1
and 9
1
of
10
BF
2
OH and the 8
1
9
1
energy levels of BF20H and
10
BF
2
OH could be reproduced using a simple Watson-type Hamiltonian. For the v
5
and v
7
bands of
11
BF
2
OH, C-type Coriolis interactions coupling the 5
1
and 7
1
energy levels with those of the 7
2
and 6
1
dark states, respectively, were accounted for in the calculation. In addition, an updated set of rotational parameters was provided for the unperturbed 8
1
and 9
1
vibrational states of
11
BF
2
OH using the data from our previous analysis. In all these cases, the upper state parameters derived in this work enabled the reproduction of both the infrared and microwave data to within experimental uncertainties.