Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1405749 | Journal of Molecular Structure | 2012 | 5 Pages |
Abstract
The molecular structure of the axial and equatorial conformers of 1-iodo-1-silacyclohexane, CH2(CH2CH2)2SiH-I, as well as thermodynamic equilibrium between these species were investigated by means of gas-phase electron diffraction (GED) and quantum chemical calculations up to MP2(full)/SDB-AUG-CC-pVTZ level of theory (MP2). According to electron diffraction data, the vapor of this compound comprises a mixture of conformers with chair conformation and Cs symmetry differing in the axial and equatorial position of the Si-I bond (axial = 73(7) mol%/equatorial = 27(7) mol%) at T = 352 K. This corresponds to a free energy difference of A = â0.59(22) kcal molâ1. The observed gas-phase electron diffraction parameters are in good agreement with those obtained from theory. NBO analysis revealed that axial conformer of 1-iodo-1-silacyclohexane is an example for electrostatic stabilization of a conformer which is unfavorable in terms of steric and conjugation interaction.
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Physical Sciences and Engineering
Chemistry
Organic Chemistry
Authors
A.V. Belyakov, A.A. Baskakov, R.J.F. Berger, N.W. Mitzel, H. Oberhammer, I. Arnason, S.Ã. Wallevik,