Aldehyde-Substituted Donor–Acceptor-Type Dithienylethenes as Novel Building Blocks for Photochromic Materials

Two novel donor-pi-acceptor-type dithienylethene derivatives, in which the triphenylamine group acts as electron donor and the formyl group functions as electron acceptor, have been developed. Their structures were confirmed by H-1 NMR, C-13 NMR and HRMS (ESI). Investigation of their photochromic properties indicated that they had good photochromic behaviour and excellent fatigue resistance on irradiation with UV or visible light. DFT calculations further validated these experimental results for photochromic behaviour. Moreover, these compounds can be utilised as versatile building blocks to construct novel near-infrared photochromic materials.