Electrochemical Ring-Opening and -Closing of a Spiropyran

The bistability of molecular switches is an essential characteristic in their use as functional components molecular-based devices and machines. For photoswitches, light-driven switching between two stable states proceeds via short-lived changes the bond order electronically excited states. Here, bistable a ditertbutyl-substituted spiropyran photoswitch instead demonstrated by oxidation subsequent reduction overall four-state cycle. structure chosen has reduced sensitivity to effect secondary electrochemical processes such H+ production provides transient access decreased thermal Z–E isomerization barrier one electron oxidized state, akin that achieved corresponding photochemical path. Thus, we show energy needed for spiropyrans merocyanine form on demand, typically delivered photon, can be provided electrochemically. This opens up further opportunities utilization electrically controlled applications devices.