Crystal Engineering Approach toward Selective Formation of an Asymmetric Supramolecular Synthon in Primary Ammonium Monocarboxylate (PAM) Salts and Their Gelation Studies

A crystal engineering approach assisted by Cambridge Structural Database (CSD) analyses was adopted in synthesizing a new series of primary ammonium monocarboxylate (PAM) salts derived from variously substituted phenylacetic acid (PA) and chiral amines (R)- and (S)-1-phenylethyl amines (PEA) with the aim of ascertaining an asymmetric one-dimensional (1D) PAM synthon (designated as synthon W) over the other symmetric possibility (synthon X). Characterization of 32 such PAM salts by single crystal X-ray diffraction (SXRD) revealed the exclusive formation of synthon W. The results suggested that the chiral ammonium components must have played a crucial role in generating exclusive formation of synthon W. Interestingly, about 28% of the PAM salts thus synthesized herein displayed gelation ability thereby emphasizing the role of 1D PAM synthon W in gelation.