Stepwise Photochromism of Bis(Imidazole Dimer) Bridged by a Sulfur Atom

We report the development of the stepwise photochromic imidazole dimer bridged by a sulfur atom. The one-photon absorption leads to the generation of the colored biradical species, which rapidly recombines to the initial imidazole dimer following first-order reaction kinetics. The further photochemical reaction of the biradical species produces the long-lived colored species, which shows intermolecular dimerization.

Automated summary

We have developed a stepwise photochromic imidazole dimer bridged by a sulfur atom. One-photon absorption leads to the formation of a colored biradical species, which quickly recombines to the original imidazole dimer following first-order reaction kinetics. The biradical species undergoes further photochemical reactions to produce a long-lived colored species, which displays intermolecular dimerization.