D. Papousek et al., High-resolution infrared spectra and simultaneous rovibrational analysis of the nu(2), nu(3), nu(5), and nu(6) bands of H3SiF, J MOL SPECT, 195(2), 1999, pp. 263-280
A high-resolution FT infrared spectrum of H3SiF (resolution 0.0024 cm(-1))
in the region 620-1130 cm(-1) was measured and used to analyze the fundamen
tal bands nu(2) (A(1)), 990.851 cm(-1); nu(3) (A(1)), 875.011 cm(-1); nu(5)
(E), 962.213 cm(-1) and nu(6) (E), 729.528 cm(-1) A total number of 7241 t
ransition wavenumbers (including 53 perturbation-allowed transitions) with
J' less than or equal to 49 have been fitted by taking into account various
Coriolis interactions, alpha-resonance terms, and e-type interactions betw
een and within the vibrational levels nu(2) = 1, nu(3) = 1, nu(5) = 1, and
nu(6) = 1. The strongest interaction in this system of levels is the x-y Co
riolis coupling between the nu(2) = 1 and nu(5) = 1 vibrational states. How
ever, it turns out that the x-y and z-type Coriolis interactions also have
to be introduced explicitly between the nu(5) = 1 and nu(6) = 1 states as w
ell as the x-y Coriolis interactions between nu(3) = 1 and nu(5) = 1, and n
u(3) = 1 and nu(6) = 1 states, in order to fit the data quantitatively. The
standard deviation of the fit was sigma = 8.6 x 10(-5) cm(-1) for 7241 tra
nsition wavenumbers and 68 fitted parameters. The sign relations between th
e fitted parameters and the possibility of fitting the parameters in differ
ent schemes are discussed. The results have been used to find close coincid
ences between the frequencies of the CO2 laser lines and the transition wav
enumbers of the nu(2) and nu(5) bands of H3SiF for the main natural isotopo
mer. We report integrated absorption band strengths which are important for
infrared laser chemistry. (C) 1999 academic Press.