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

Abstract

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 [(Oda2-)(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 Oda2- 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.