Molecular Dynamics Simulation of the Solvated Environment of 18-Crown-6 Ether in Mixed Ethanol–Dimethylsulfoxide

The number of ethanol molecules (EtOH) in the solvate environment of 18-crown-6 (18C6) ether is determined by molecular dynamics, depending on the concentration of dimethylsulfoxide (DMSO) in the EtOH–DMSO binary mixture (χ_DMSO = 0.0–0.8 mole fraction). The probabilities of the formation of hydrogen bonds between molecules of 18C6–EtOH, DMSO–EtOH, and EtOH–EtOH are calculated along with their average numbers and lifetimes. It is assumed that macrocycle re-solvation is virtually complete at χ_DMSO ~ 0.6 mole fraction. It is established that the ability of EtOH molecules to form hydrogen bonds with 18C6, DMSO, and with each other declines as the concentration of DMSO in the binary mixture rises. It is shown that the lifetimes of the EtOH–DMSO hydrogen bonds are longer than those for 18C6–EtOH and EtOH–EtOH.