Versatile chiroptics of peptide-induced assemblies of metalloporphyrins

Zinc porphyrin functionalized with double long-chain alkylated L-glutamide (GTPP-Zn) was synthesized for the first time, and its self-assembling behaviour was investigated in nonpolar organic solvents. The uniqueness of this functionalized porphyrin is characterized by its drastic colour change from dark green to purple via the formation of chirally stacked structures through selective axial coordination on zinc with pyridine derivatives. In this paper, we report the versatility of the GTPP-Zn assembly process as a stimuli-responsive chiroptical switching system and describe the remarkable ligand-specific induction of secondary chirality accompanied by aggregation morphological change.