Probing self‐associated structures of the solute molecule, acrylonitrile, the solvent molecule 2Cl‐phenol and their binary complexes via concentration‐dependent Raman study and DFT calculation

Abstract

AbstractRaman study of CN‐stretching mode of acrylonitrile and ring‐breathing mode of 2Cl‐phenol was made in the binary mixture of (acrylonitrile + 2Cl‐phenol) at different molar ratios of the two components. Raman spectra were recorded in the different spectral regions, 990–1070 cm−1 and 2170–2300 cm−1. Ring‐breathing mode of 2Cl‐phenol exhibited two components, which were attributed to the neat and self‐associated dimer of 2Cl‐phenol molecules. The self‐associated structure of the dimer was obtained by geometry optimization. Other structures, which were calculated, include self‐associated structure of acrylonitrile and the hydrogen‐bonded complex of (acrylonitrile + 2Cl‐phenol). All the geometry optimizations were made using density functional theory (DFT) and B3LYP functional employing the 6–31 + G(d,p) basis set. The variations of the linewidth and the peak position with concentration are explained on the basis of a model, which includes both the effect of concentration fluctuation in a microscopic volume and the influence of concentration‐dependent microviscosity based on a model proposed recently by our group. Copyright © 2006 John Wiley & Sons, Ltd.