Vibrational study of acrylonitrile dimer and acrylonitrile-water hydrogen-bonded complexes in solid neon supported by ab initio calculations

Abstract

For the first time the experimental study of the complexation of acrylonitrile molecule (CH2=CHCN, noted AN) with water has been undertaken from a vibrational point of view as well as the homodimer (AN)2 in solid neon from 80 to 6000 cm−1 using Fourier transform infrared spectroscopy. From concentration effects and with the help of theoretical results we have identified several vibrational transitions for AN homodimer, AN-H2O, AN-(H2O)2, and (AN)2-H2O complexes. For the AN-H2O complex, in which the two submolecules interacting through hydrogen bonding, the infrared spectral changes (frequencies as well as intensities) indicate that the water plays the role of the proton donor. We highlight the presence of three and two isomers for the AN-H2O and AN-(H2O)2 complexes, respectively. Theoretical calculations at the second-order Møller-Plesset level have been performed to obtain their equilibrium geometries and vibrational spectra at the harmonic level and comparison with experimental data allows us to give structures of AN-H2O and AN-(H2O)2, complexes.