Conformational Analysis of (1,1′-Phenyl-1,1′-silacyclohex-1-yl)disiloxane. DFT and Low-Temperature 13C NMR Spectroscopy Study
- Authors: Shainyan B.A.1, Kleinpeter E.2, Suslova E.N.1
-
Affiliations:
- I.A. Favorskii Institute of Chemistry
- Institute of Chemistry
- Issue: Vol 89, No 4 (2019)
- Pages: 713-716
- Section: Article
- URL: https://journals.rcsi.science/1070-3632/article/view/222855
- DOI: https://doi.org/10.1134/S1070363219040121
- ID: 222855
Cite item
Abstract
The DFT and MP2 theoretical conformational analysis of the recently synthesized (1,1′-phenyl-1,1′-silacyclohex-1-yl)disiloxane has revealed the energetic preference of the Phax,Phax conformer. The Phax,Phax: Phax,Pheq: Pheq,Pheq conformers ratio has been estimated as of 46.6: 33.1: 20.3 from the M062X/6-311G(d,p) free energy simulation, suggesting the possibility of detecting individual conformers experimentally, e.g., by low-temperature 1H and 13C NMR spectroscopy. However, only the presence of several conformers has been detected by means of 1H NMR spectroscopy at 113 K; determination of the Δν (Hz) and ΔG# (kcal/mol) parameters for the 6-membered ring interconversion has been impossible due to the signals broadening at low temperature, signal temperature shifts, and extremely low barrier of ring inversion at Tc < 113 K.
About the authors
B. A. Shainyan
I.A. Favorskii Institute of Chemistry
Author for correspondence.
Email: bagrat@irioch.irk.ru
Russian Federation, ul. Favorskogo 1, Irkutsk, 664033
E. Kleinpeter
Institute of Chemistry
Email: bagrat@irioch.irk.ru
Germany, Potsdam
E. N. Suslova
I.A. Favorskii Institute of Chemistry
Email: bagrat@irioch.irk.ru
Russian Federation, ul. Favorskogo 1, Irkutsk, 664033