FT-IR studies of molecular interactions in formamide–methanol mixtures

FT-IR spectra of formamide (FA)–methanol (MeOH) mixtures have been measured by ATR technique. Factor analysis applied to the spectra has shown two kinds of intermolecular complexes differing in a manner of polarization of component molecules. The composition of the complexes changes monotonically with the composition of the mixtures. The spectra in the CO stretching region have been analyzed separately using both: the factor analysis and the difference spectra method. Four different environments of carbonyl group of formamide has been revealed over the whole range of the mixture composition. The mean number of formamide molecules disturbed by one methanol molecule via carbonyl group in the formamide-rich region has been found as equal to 1.5. Presumable structures for the molecular complexes have been proposed to explain the results of the analyses.