Effect of proton donors on the intramolecular coordination C=O→Si-F in (acyloxymethyl)trifluorosilanes. Ab initio, DFT and FTIR study, QTAIM analysis

• Published in: Journal of physical organic chemistry 2014-11, Vol.27 (11), p.892-901
• Main Authors: Chipanina, Nina N., Lazareva, Nataliya F., Aksamentova, Tamara N., Doronina, Evgeniya P., Shainyan, Bagrat A.
• Format: Article
• Language: English
• Subjects: (Acyloxymethyl)trifluorosilanes; DFT and MP2 calculations; Fourier transforms; FTIR; Hydrogen bonding; Hydrogen bonds; Pentacoordinated silicon compounds; QTAIM analysis
• ISSN: 0894-3230; 1099-1395
• DOI: 10.1002/poc.3352

The intramolecular С=O→Si coordination in H‐complexes of (acetoxymethyl)trifluorosilane and (benzoyloxymethyl)trifluorosilane with proton donors HCl, PhOH, MeOH, and CHCl3 was investigated by density functional theory and second‐order Møller‐Plesset perturbation theory (MP2) methods. Interrelation and mutual influence of the intramolecular coordination bond С=O→Si and intermolecular hydrogen bonds C=O···H and Si–F···H in H‐complexes was established using the AIM and NBO analyses. The С=O→Si coordination is weakened by the C=O···H hydrogen bonding but enhanced by the Si–Fax···H hydrogen bonding. The structure of H‐complexes of (acetoxymethyl)trifluorosilane with proton donors in solution was determined by comparing the ν(C=O) and ν(Si–F) frequencies calculated using the conductor‐like polarizable continuum model and their experimental Fourier transform infrared values. Copyright © 2014 John Wiley & Sons, Ltd. The intramolecular O→Si coordination in the molecules of (acetoxymethyl)trifluorosilane and (benzoyloxymehyl)trifluorosilane and formation of their complexes with H‐donors was investigated by the methods of quantum chemistry and FTIR spectroscopy. The interplay between the intramolecular O→Si coordination bond and the intermolecular O···H and F···H h‐bonds was analyzed. The structure of H‐complexes of (acetoxymethyl)trifluorosilane with H‐donors in solution was determined by comparing the experimental FTIR frequencies with those calculated using C‐PCM model.