Silica covering driven intensity enhancement and handedness inversion of the CPL signals of the supramolecular assemblies

Abstract

A pair of Phe–Phe dipeptides with a tolane group were synthesized by introducing tolane with high emission efficiency to phenylalanine dipeptide. The sodium salts of the dipeptides were able to self-assemble into straight belts in a mixture of methanol and water. The supramolecular assemblies exhibited circularly polarized luminescence (CPL) properties. They can be used as templates to prepare dipeptide-based hybrid silicas through a supramolecular templating approach. The hybrid materials formed coiled nanoribbons, which showed a distinct and different morphology compared to supramolecular assemblies. Moreover, since silica covering can affect the packing structures of the tolane groups, the intensity of the CPL was enhanced and its handedness was inversed.