Electrochromic materials using mechanically interlocked molecules.

Recent investigations on the design and synthesis of electrochromic materials based on switchable three-station [2]catenanes are summarized. The reasoning and preliminary experiments behind the design of electrochemically controllable red-green-blue (RGB), donor-acceptor [2]catenanes are presented. A basis for color generation is discussed in which the tetracationic cyclophane, cyclobis(paraquat--phenylene), serves as the π-electron deficient ring which circumrotates between three π-electron rich recognition sites within a macrocyclic polyether, generating the three different colors (RGB) based on the different charge transfer interactions between the tetracationic cyclophane and recognition sites based on 1,5-dioxynaphthalene (R), tetrathiafulvalene (G) and benzidine (B).