ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
The microwave spectra in the region from 18.5 to 39.0 GHz have been measured and assigned for the following isotopic species of trifluoromethyl silane: CF328SiH3, CF329SiH3, CF330SiH3, CF328SiD3, CF329SiD3, CF330SiD3, CF328SiDH2, CF329SiDH2, CF328SiD2H, and CF329SiD2H. In addition to the vibrational ground state, two torsionally excited states were assigned for some of the asymmetrically substituted molecules whereas as many as thirteen states involving multiple excitation of the torsional and/or CF3 rocking modes were assigned for some of the symmetric rotor species. From a least squares adjustment to fit 18 rotational constants for the vibrational ground state, the following r0 structural parameters were obtained: r(C–F) =1.3600±0.0029 A(ring), r(C–Si)=1.8997±0.0071 A(ring), r(Si–H)=1.4600±0.0007 A(ring), r(Si–H) =1.4600±0.0007 A(ring), CSiH=107.15±0.03°, and FCSi=113.28±0.30°. The rs structural parameters were obtained for the SiH3 moiety and were found to be r(Si–H) =1.4598±0.0033 A(ring) and CSiH=107.17±0.09°. The dipole moment was obtained from the ground state Stark effect measurements on CF328SiDH2 and was found to be ||μa||=2.32±0.02 D. The barrier to internal rotation is estimated from relative intensity measurements to be 403±20 cm−1 (1.15±0.06 kcal/mol). These results are compared to the corresponding parameters of some similar molecules.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.454181
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