An Electrochromic Tristable Molecular Switch

• DOI: 10.1021/jacs.5b09274
• Publication Date: 2015-10-06T14:09:12Z
• Authors: Junling Sun; Yilei Wu; Yuping Wang; Zhichang Liu; Chuyang Cheng; Karel J. Hartlieb; Michael R. Wasiel...; J. Fraser Stoddart
• Keywords: Molecular switch

A tristable [2]catenane, composed of a macrocyclic polyether incorporating 1,5-dioxynaphthalene (DNP) and tetrathiafulvalene (TTF) units along with 4,4'-bipyridinium (BIPY(•+)) radical cation as three very different potential recognition sites, interlocked mechanically the tetracationic cyclophane, cyclobis(paraquat-p-phenylene) (CBPQT(4+)), was synthesized by donor-acceptor templation, employing "threading-followed-by-cyclization" approach. In this catenane, movement CBPQT(4+) ring in its redox states among these corresponding color changes, is achieved tuning external potentials. starting state, where no applied, encircles TTF unit displays green color. Upon oxidation unit, moves to DNP producing red Finally, if all BIPY(2+) are reduced BIPY(•+) cations, resulting CBPQT(2(•+)) diradical dication will migrate purple These readily switchable electrochromic properties render [2]catenane attractive for use electro-optical devices.