Complex formation in liquid diethyl ether-chloroform mixtures examined by 2D correlation MID-IR spectroscopy

•Complex formation in diethyl ether-chloroform was investigated by Mid-IR spectroscopy.•2D COS, 2D CDS and excess spectroscopy were used for the analysis of IR absorbance spectra.•The optimal geometry of complex and its spectrum were obtained by DFT B3LYP/cc-pVTz calculations.•Spectral and concentration profiles of mixture components were obtained by using of MCR decomposition.

Molecular complexes formation in diethyl ether-chloroform liquid solution is investigated by Mid-IR absorbance spectroscopy. The spectra were measured in spectral ranges of 1000–1550 cm−1 and 2650–3100 cm−1. 2D correlation analysis of spectral data indicates the presence of a third component in the solution. Excess spectroscopy shows that maximum of complex concentration is concentrated at around of 55% (vol.) of diethyl ether. 2D codistribution analysis supports such conclusion and provides the order of species distribution. Three-components MCR decomposition of spectral data was performed for the determination of concentration and spectral profiles of mixture components. Spectral transformations due to intermolecular interactions are in full agreement with those calculated according to density functional theory with B3LYP functional and cc-pVTz basis set for the case of equimolecular complex.