Eleven supramolecular adducts of 5,7-dimethyl-1,8-naphthyridine-2-amine and organic acids assembled by classical hydrogen bonds and other noncovalent intermolecular interactions

Supramolecular networks and Hirshfeld surfaces of oxydiacetic acid and iminodiacetic acid salts

Oxydiacetic acid (Oda) and iminodiacetic acid (Ida) have been combined with two diamines, namely ethylenediamine (en) and o-phenylenediamine (o-phen), to give three molecular crystals of compositions [(Oda^2-)(en²⁺)]·H₂O (Odaen), [(Ida^-)(0.5en⁺)] (Idaen) and [(Oda^-)(o-phen⁺)] (Odaophen). Single crystal X-ray structure determination of the three molecular salts revealed that the hydrogen bonding interactions form distinct supramolecular chains. In Odaen, water molecules and Oda^2- anions generate one-dimensional supramolecular chains where two chains overlap each other in zigzag form. In Odaophen, Oda^- anions generate a one-dimensional linear supramolecular chain. In Idaen, both intermolecular and intramolecular proton transfer occurs. Ida^- anions generate a one-dimensional zigzag chain. These one-dimensional supramolecular chains extend to form different two-dimensional supramolecular chains by the interaction of diaminium and monoaminium cations. Intermolecular close contacts are also examined using Hirshfeld analysis to reveal similarities and differences in the crystal structures.