Molecular dynamics simulation of the solvated environment of 18-crown-6 ether in methanol-acetonitrile mixed solvents

In this study, the structure of the molecular system 18-crown-6 ether - methanol-acetonitrile has been investigated by using molecular dynamics modeling. The results reveal that for all compositions of the mixed solvents, the macrocycle molecule is involved in the formation of five, six hydrogen bonds with methanol. The solvation of 18C6 by molecules of AN occurs due to electron donor-acceptor (EDA) interactions: one of the molecular complexes (1:1) is formed in the AN concentration range from 0.4 to 0.8 mole fractions; in pure AN is possible the formation of the 1:2 complex in which both molecules of AN are EDA-bonded to the oxygen atoms of 18C6. This study shows that EDA interactions are possible between methanol and acetonitrile molecules. (C) 2020 Elsevier B.V. All rights reserved.