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

Abstract

The intramolecular С=OSi 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 Moller-Plesset perturbation theory (MP2) methods. Interrelation and mutual influence of the intramolecular coordination bond С=OSi and intermolecular hydrogen bonds C=O···H and Si–F···H in H-complexes was established using the AIM and NBO analyses. The С=OSi 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.