PREFERENTIAL SOLVATION OF AMIDES BY METHANOL – A COMPARISON OF MOLECULAR DYNAMICS CALCULATIONS WITH THE EXPERIMENTAL DATA

Abstract

Using the Kirkwood-Buff theory of solutions, the preferential solvation of the N-methylacetamide (NMA), N-methylformamide, (NMF), and N,N-dimethylformamide, (DMF), molecule has been investigated in the binary famide+methanolg mixtures at 313.15 K. Moreover, for the famide+methanolg mixtures, where amide = NMF, DMF, and NMA, the molecular dynamics calculations at x_amide = 0.518 were performed. From the obtained molecule-molecule radial distribution functions, (rdf), and atom-atom rdf, it was possible to estimate the local mole fractions around the amide molecule, the orientation effects of molecules within the solvation shell, and a possibility of the formation of complexes. The general picture obtained from analysis of the molecular dynamics results is consistent with the deductions derived from thermodynamic data.