Design, Synthesis, and Electrochromic Behaviors of Donor‐Acceptor‐Donor type Triphenylamine‐iso‐Naphthalenediimide Derivatives

Abstract To investigate the influence of number of electropolymerizable group of the donor side on electrochromic behaviors, three donor‐acceptor‐donor type monomers containing isonaphthalene diimide as acceptor core and electro‐polymerizable triphenyl amine (TPA) as the donor moiety have been designed and successfully synthesized via imidization of isonaphthalene anhydride with corresponding TPA derivatives. DFT calculations have predicted that electron density of HOMO is centralized on peripheral TPA unit and the same of LUMO is localized on central moiety. Polymer films from three monomers are electrodeposited on ITO/glass electrodes and have been characterized by cyclic voltammetry. Three polymers show multi electrochromic properties in a reversible manner with the color change from colorless to brown to blue at low working potential. Spectro‐electrochemistry studies of these films have revealed the high optical contrast (51.4 %, 69.8 %, 84.5 % respectively) of these polymers with the very fast bleaching (less than 1 s) and coloration (less than 2 s) time with very high coloration efficiencies. The electro switching stability has been performed up to 500 cycles and activity loses only 10 % after 3000 s. To demonstrate the potentials of these derivatives, solid‐state devices having these derivatives provide electrochromism in a very nice way without taking any protective precaution from air/moisture and its spectro‐electrochemistry behaviors have been also explored.