Infrared and Millimeter-Wave Study of the Four Lowest Torsional States of CH3CF3

Vibration–Torsion–Rotation Study of the ν5 State of CH3CF3

“…The theoretical framework for the current paper lies in three earlier works on internal rotation in symmetric rotors (2,4,8). Ozier et al (8) (4,8) to treat the matrix elements off-diagonal in k. In so far as possible, the notation will follow that of Ref.…”

“…High sensitivity Fourier transform infrared spectroscopy has been used to measure the perturbation-allowed torsional overtone (v 6 = 2 ← 0) (4). In addition, two extensive studies of the pure rotational spectrum in the gs have been reported recently (4,9); these provide valuable information on the J -dependence of the torsion-rotation energies. The previously available data on the gs of CH 3 CF 3 have been analyzed by Wang et al (4) by treating the gs as being isolated from the excited vibrational states; the molecular parameters obtained in this One Band Model are given in Table 5 of Ref.…”

“…Ozier et al (8) (4,8) to treat the matrix elements off-diagonal in k. In so far as possible, the notation will follow that of Ref. (2).…”

“…The previously available 1494 frequencies for the gs of CH 3 CF 3 are summarized in Table 1 of Ref. (4). In contrast to the case of the asymmetric rotor, the torsional part of the Hamiltonian presents particular difficulty because it does not affect the allowed pure rotational spectrum for a symmetric top in lowest order.…”

“…The previously available data on the gs of CH 3 CF 3 have been analyzed by Wang et al (4) by treating the gs as being isolated from the excited vibrational states; the molecular parameters obtained in this One Band Model are given in Table 5 of Ref. (4).…”