Vibrational spectra and force constants of symmetric tops: High resolution spectra of monoisotopic H _{3}SiCl in the 2200cm ^{1} region and rovibrational analysis of the ν_{1} and ν_{4} fundamentals
Abstract
The gas phase infrared spectra of monoisotopic H _{3}Si ^{35}Cl and H _{3}Si ^{37}Cl have been studied in the {ν _{1}}/{ν _{4}} region near 2200 cm ^{1} with a resolution of 0.012 and 0.04 cm ^{1}, respectively, and rotational fine structure for ∆ J = ±1 branches has been resolved. In addition, some information on ν_{3} + ν_{4} of H _{3}Si ^{35}Cl near 2750 cm ^{1} has been obtained. ν_{1} and ν_{4} are weakly coupled by Coriolis x, y resonance, B Ω_{14}ζ _{14} ∼ 2 × 10 ^{3}cm^{1}, only the upper states K' = 2, l = 0 and K' = 1, l = 1 being substantially affected. Local perturbation due to rotational l(±1, ±1)type resonance with ν_{3} + ν_{5}^{+1} + ν_{6}^{+1} and ν_{3} + ν_{5}^{+1} + ν_{6}^{1} is revealed in the ∆ K = +1 and 1 branches, respectively. From a fit of the experimental line positions, standard deviations of 1.4 and 3.8 × 10 ^{3} cm ^{1}, respectively, to a model with five interacting levels conventional excited state parameters and interaction constants have been obtained. In {H _{3}Si ^{35}Cl }/{H _{3}Si ^{37}Cl } the fundamentals are ν_{1}, {2201.94380(15)}/{2201.9345(7)} and ν_{4}, {2209.63862(8)}/{2209.6254(2) cm^{1}}, respectively. Q branches of the "hot" band ( ν_{3} + ν_{4})  ν_{3} and of ν_{4} of the ^{29}Si and ^{30}Si species have been detected.
 Publication:

Journal of Molecular Spectroscopy
 Pub Date:
 November 1983
 DOI:
 10.1016/00222852(83)902345
 Bibcode:
 1983JMoSp.102..160B