Tripodal N-Functionalized Arylazo-3,5-dimethylpyrazole Derivatives of Trimesic Acid: Photochromic Materials for Rewritable Imaging Applications

The development of solid-state photochromic materials is both challenging and important considering their potential applications. Herein, we report the development of tripodal N-functionalized arylazo-3,5-dimethylpyrazole derivatives of trimesic acid as a new class of photochromic materials for rewritable imaging applications. The highlights of this class of compounds are a high percentage ZZZ-photoisomerization, a long half-life for the ZZZ-isomer and good solubility, facilitating solution processing. Furthermore, all derivatives exhibit photochromism in the solid state. Remarkably, most of the synthesized compounds also show contrasting colour changes rendering them useful in rewritable imaging applications.