Intra- and intermolecular hydrogen bonds in ethylene glycol, monoethanolamine, and ethylenediamine

The structures of ethylene glycol, aminoethanol, ethylenediamine, and their dimers with the formation of hydrogen bonds of different types are optimized by density functional theory (DFT) using hybrid functional B3LYP in the basis of 6-31++G(d,p), 6-311++G(2d,2p) and aug-CC-pVTZ. Energies of interactions, hydrogen bond parameters, and oscillation frequency are calculated, and NBO analysis is performed. The types of hydrogen bonds formed in dimers of 1,2-disubstituted ethanes X-CH2-CH2-Y (X, Y = OH, NH2) are established.