Supramolecular Host-Guest Hydrogel Based on γ-Cyclodextrin and Carboxybenzyl Viologen Showing Reversible Photochromism and Photomodulable Fluorescence

Much effort has been devoted to the development of supramolecular hydrogels due to their broad applications and conveniently controllable properties. Here, we demonstrate a novel supramolecular host- guest hydrogel, which is constructed by the host gamma-CD complexed with the guest 1-(4-carboxybenzyl)-4,4 '-bipyridinium chloride (1+center dot Cl-) through the pi center dot center dot center dot pi interaction, hydrogen bonding, and host-guest interactions. The supramolecular hydrogel [1+@gamma-CD]n exhibits reversible electron transfer photochromic behavior and photomodulable fluorescence. The excellent photochromic and fluorescence properties support the practical utility of the supramolecular hydrogel as a visual display and anti-counterfeiting material.

Automated summary

We demonstrated a novel supramolecular host-guest hydrogel, which is constructed by the complexation of the host gamma-CD with the guest 1-(4-carboxybenzyl)-4,4'-bipyridinium chloride through multiple interactions. The supramolecular hydrogel exhibits reversible electron transfer photochromic behavior and photomodulable fluorescence, making it suitable for visual display and anti-counterfeiting applications.