Electronic and optical properties of dibenzothiophen-S,S-dioxide and EDOT based conducting polymers

Among various techniques, utilization of donor–acceptor–donor (DAD) approach is known to be powerful in tuning the color of the conducting polymers. For this purpose, a new DAD type monomer 3,7-di(2,3-dihydrothieno[3,4-b][1,4]dioxin-7-yl) dibenzothiophen-S,S-dioxide (EDOTSO2) was developed through Stille cross coupling between tributyl(2,3-dihydrothieno[3,4-b][1,4]dioxin-7-yl)tin and 3,7-dibromodibenzothiophen-S,S-dioxide. EDOTSO2 was polymerized electrochemically and the resultant polymer displayed color alternation from yellow to purple upon oxidation. Furthermore, EDOTSO2 was subjected to electrochemical copolymerization in the presence of 3,4-ethylenedioxythiophene (EDOT) under both potentiodynamic and potentiostatic techniques. Spectroelectrochemical analysis demonstrated that the neutral copolymers possess reveal a shift in their dominant wavelength of absorbance upon increasing applied potential. Both homopolymer and the copolymers were characterized by means of cyclic voltammetry, FTIR, spectroelectrochemistry, kinetic properties and electrochromic device performance of EDOTSO2 based systems were highlighted.