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

摘要

The intramolecular С=O→Si coordination in H-complexes of (acetoxymethyl)trifluorosilane and (benzoyloxymethyl)trifluorosilane with proton donors HCl, PhOH, MeOH, and CHCl_3 was investigated by density functional theory and second-order M?ller-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-F_(ax)···H hydrogen bonding. The structure of Hcomplexes 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.