The photochromic switchable imidazoles: Their genesis, development, synthesis, and characterization

Switchable photochromic dyes have benefited greatly from the use of heterocyclic chemicals. The imidazole group is particularly essential because it can be transformed into dimers, which can then be radicalized in the presence of light photons. Imidazole dimers have been optimized throughout thirty years of research, allowing derivatives with diverse colors, quick reversibility, and sensitivity to different wavelengths from UV to near IR ranges. These imidazole dimers are interesting to be used in the matrices of polymers, hydrogels, glasses, solar cells, and even pharmaceuticals. The goal of this review is to look at the history, development, and future of imidazole dimers. We will also cover some heterocyclic structures derived from these compounds.