Photocontrol of ionic conduction by photochromic crown ethers

Crown ether derivatives carrying a photochromic moiety, photochromic crown ethers, are attractive key materials for photochemical control of ionic conduction in the solid or quasi-solid state. The photochromic crown ethers can modify ionic conduction in two modes. A mode for photocontrol of ionic conduction is based on molecular control in complexation of cations that are ion-conducting carriers by crown ethers incorporating a photochromic moiety such as spirobenzopyran, spironaphthoxazine, and Malachite Green dye. Another mode is based on photoinduced changes in the phase and molecular orientation of the crown moieties that are ion-hopping sites by using crowed azobenzene derivatives capable of forming highly-ordered liquid crystal phases such as smectic and cholesteric phases.