Analysis of spectral data by complementary methods: Inspection of the molecular complex in N,N-dimethylformamide–methanol mixtures

FT-IR spectra of N,N-dimethylformamide (DMF)–methanol (MeOH) mixtures have been measured in the range of 4000–950 cm−1. The data have been analyzed using the difference spectra method and factor analysis. The usefulness of the methods for recognizing the hydrogen bonds in the mixtures has been critically examined. It has been shown that 1:1 intermolecular complex existing in the whole range of the mixture composition is modified by interactions with environment. The structure of different forms of the complex depending on the solvent composition has been shown. Weak CH⋯OCH⋯O hydrogen bonds have been postulated for explanation of the spectra.