Extending Primary Ammonium Dicarboxylate (PAD) to Diprimary Ammonium Dicarboxylate (DPAD) Synthon and Its Implication in Supramolecular Gelation

A series of organic salts derived
from various dicarboxylic acids
and two α,ω-diamines, namely, 1,3-diaminopropane and 1,4-diaminobutane,
were prepared and characterized by various physicochemical techniques,
including single-crystal X-ray diffraction, with the aim of extending
the well-studied 2D primary ammonium dicarboxylate (PAD) supramolecular
synthon in the context of supramolecular gelation. Single crystal
structures of 9 out of 14 diprimary ammonium dicarboxylate (DPAD) salts were determined. The results showed that none
of the salts displayed the expected 2D DPAD synthon;
instead, all of them self-assembled into a 3D hydrogen-bonded network.
Consequently, only two salts, namely, B3FA and B4SA, appeared to show gelation behavior producing weak
gelsa finding that corroborated well with the current understanding
of gelation.