Methanol and acetonitrile associates in aqueous and chloroform solutions according to 1H NMR spectroscopic data

Association of methanol and acetonitrile in a nonpolar (CDCl3) and polar (H2O and D2O) solvents was studied by 1H NMR spectroscopy and quantum chemistry. The results were compared with the data obtained by decomposition of the spectral curves in the range 800–1100 nm by the independent component analysis (ICA) technique. The content of homoassociates consisting of four and two or three molecules in the case of methanol and acetonitrile, respectively, gradually increased with the amount of the organic solvent in solution. The aqueous solutions under study consisted of few associates of compositions 1: 1, 1: 2, and 1: 4.5 for acetonitrile and 1: 1 and 1: 3 for methanol (water: organic solvent). The quantum-chemical calculation of the NMR spectra of the particles existing in solution confirmed our conclusions about the structure of the solutions.