Diarylethenes with a Narrow Singlet–Triplet Energy Gap Sensitizer: a Simple Strategy for Efficient Visible-Light Photochromism

摘要

All-organic visible-light photochromism is reported here via a novel strategyrnwith narrow singlet–triplet energy gap (ΔEST) materials as a sensitizer. Takingrnadvantage of the narrow ΔEST feature and the triplet–triplet energy transferrnprocess, highly efficient photochromism of diarylethenes (DAEs) with bothrnring-open and ring-closure excitations shifted to visible light region is successfullyrnachieved. Moreover, the wavelength of the visible excitation lightrncan be easily modulated (e.g., from 405 to 470 nm) by elaborate selectionrnof matched sensitized molecules. The “write-and-erase” application of thisrnphotochromic system in polymer films is further demonstrated. This strategyrnprovides a simple and versatile selection of well-matched DAE/sensitizer couplesrnfor visible-light photochromism without complicated molecular design.