Structure of a Liquid Monoethanolamine–Water System: Describing Networks of Mixed Hydrogen Bonds

Mixed networks of hydrogen bonds in a water–monoethanolamine (MEA) liquid system formed from solvents with a spatial network of hydrogen bonds are described topologically. This allows the comparison of networks of different systems and selection of the best one (particularly for cryobiological problems). The coordinates of atoms in the Н2О–MEA system are obtained via molecular dynamics (MD). The mixed network is described by means of graph theory and Delaunay simplices at 300 K throughout the range of concentration of monoethanolamine in water, based on MD results. Earlier works and published data on structure and interaction in the system are used to explain the observations. The amine group of a MEA molecule plays a key role in the formation of the MEA⋅H2O stable complex in the mixed network of H-bonds of the system in the entire concentration range. The graph theory results are compared to ones obtained with Delaunay simplices. The results are compared to similar studies of the mixed network of a H2O–EG system.