Siberian Federal University

The paper presents the results of synthesis and investigation of binary and ternary systems of deep eutectic solvents based on pentaerythritol, urea and choline chloride. Investigations of the DES systems by IR spectroscopy allowed to assume the mechanism of donor-acceptor interaction of their components with the formation of a molecular complex. The presence of a large number of hydrogen bonds leads to a decrease in the melting/crystallisation temperature of eutectic DES compositions, which is explained by intermolecular forces and self-association at donor-acceptor interaction of components. This interaction leads to a decrease in the lattice energy between the DES molecules and the destruction of the solid crystal structures of the DES components. As a result, less energy is required to melt the molecules than to melt the individual components