Reversible Circularly Polarized Luminescence Inversion and Emission Color Switching in Photo-Modulated Supramolecular Polymer for Multi-Modal Information Encryption.

Abstract

Constructing circularly polarized luminescence (CPL) materials that exhibit dynamic handedness inversion and emissive color modulation for multimodal information encryption presents both a significant challenge and a compelling opportunity. Here, we have developed a pyridinethiazole acrylonitrile-cholesterol derivative (Z-PTC) that exhibits wavelength-dependent photoisomerization and photocyclization, enabling dynamic handedness inversion and emissive color modulation in supramolecular assemblies with decent CPL activity. Coordination with Ag⁺ ions form the Z-PTC Ag supramolecular polymer (SP₁), which assembles into nanotubes displaying enhanced positive yellow-green CPL. Irradiation at 454 nm transforms SP₁ into nanospheres of a mixture supramolecular polymer (SP₂) of Z/E-PTC Ag, displaying inverted supramolecular chirality and emitting negative orange-yellow CPL. Reheating SP₂ to 343 K restores the original nanotube structure via excellent reversible photoisomerization. Exposure to 365 nm light also induces CPL inversion from positive to negative and triggers morphological changes from SP₁ to SP₂. Prolonged irradiation causes further transformation into irregular supramolecular aggregate, shifting the emission color to blue and eliminating CPL. These dynamic properties of the multicolor CPL system, including reversible handedness inversion, can also be realized in the semisolid state, exhibiting promising potential for multimodal information encryption applications with enhanced security and complexity.