ISSN:
1572-9001
Keywords:
Conformational stability
;
structural parameters
;
infrared and Raman intensities
;
allylsilane
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The Raman spectra (3500 to 30 cm−1) of allylsilane, CH2CHCH2SiH3, in the liquid with quantitative depolarization ratios and solid states and the infrared spectra (3500 to 30 cm−1) of the gas and solid have been recorded. Similar data have also been recorded for the Si-d3 isotopomer. Additionally, the mid-infrared spectra of the normal sample dissolved in liquified xenon as a function of temperature (−100 to −50°C) have been recorded. All these data indicate there is a single conformer, the gauche rotamer, in all three physical states. Utilizing the Si-H stretching frequencies from the infrared spectrum of the gaseous CH2CHCH2SiD2H isotopomer, the three Si-H bond distances (r 0) are calculated to be 1.484 Å for the gauche conformer. The other r 0 parameters are estimated from the previously reported rotational constants. The fundamental frequencies for the asymmetric (78 cm−1) and SiH3 (137 cm−1) torsions were obtained from sum and difference bands with the SiH3 stretches. From the SiH3 torsional frequency the barrier to internal rotation is calculated to have a value of 731 cm−1 (8.74 kJ/mol). The optimized geometries, conformational stabilities, harmonic force fields, infrared intensities, Raman activities, depolarization ratios, and vibrational frequencies have been obtained from RHF/6-31G* and/or MP2/6-31G* ab initio calculations. These quantities are compared to the corresponding experimental quantities when appropriate as well as with some corresponding results for some similar molecules.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1022478913441
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