The proton transfer and hydrogen bonding complexes of (2-hydroxyethyl)amines with acids: A theoretical study

► Triethanolamine affords with carboxylic acids hydrogen bonding and proton transfer complexes. ► Contrary to triethanolamine mono- and di-ethanolamines form only hydrogen bonding complexes. ► The main factor affecting the stability of triethanolamine complexes is bifurcated hydrogen bonding. ► Triethanolamine acts as a proton donor and as a proton acceptor in these complexes.