Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5415902 | Journal of Molecular Spectroscopy | 2007 | 8 Pages |
Abstract
High level ab initio and DFT calculations have been carried out for silacyclopent-2-ene and its 1,1-d2, 1,1-difluoro, and 1,1-dichloro derivatives. The previously published far-infrared spectra of the ring-puckering vibration, which had been interpreted to be characteristic of a rigid planar molecule, have been reanalyzed for the hydride and 1,1-d2 derivative. Both the spectra and the theoretical calculations show the molecule to have a small barrier to planarity. The experimental data analyzed with a Gaussian barrier produce a barrier of 49 cmâ1 as compared to a value of 47 cmâ1 computed using the CCSD/6-311++G(d,p) basis set. The experimental value for the deuteride was determined to be 41 cmâ1 from the one-dimensional approximation. All MP2 and DFT computations for the 1,1-difluoro derivative predict a planar structure whereas the MP2 computation when used with triple-ζ basis set predicts a barrier of 13 cmâ1 for the chloride. Vibrational frequencies were also computed for these molecules and compared to experimental results for the characteristic frequencies for these types of molecules.
Related Topics
Physical Sciences and Engineering
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Physical and Theoretical Chemistry
Authors
Abdulaziz A. Al-Saadi, Niklas Meinander, Jaan Laane,