Conformational Heterogeneity, Self-Assembly, and Gas Adsorption Studies of Isomeric Hybrid Peptides

The folding and self-assembly propensities of three synthetic isomeric aliphatic–aromatic backbone hybrid peptides are illustrated. Single crystal X-ray diffraction studies of three isomeric hybrid dipeptides Boc-Phe-x-aminobenzoic acid (x = o/m/p) reveal that the peptides adopt unconventional conformations which self-assemble to form diverse supramolecular architectures using hydrogen bonding interactions and other noncovalent interactions in the solid state. The N₂ sorption propensities of the isomeric hybrid peptides in the solid state significantly vary with folding and self-assembly nature. The peptides 1 and 2 exhibit type-III N₂ sorption isotherm, though peptide 1 adsorbs 2-fold higher N₂ than does peptide 2.