Synthesis of 1,1,4,4-Tetra-aryl-1,3-butadienes Possessing Sulfur Substituents at 2,3-Positions via Dithiol Intermediate and Their Characteristic Electrochromic Behaviors

Abstract Synthesis and reactions of 2,3-dimercapto-1,1,4,4-tetra-aryl-1,3-butadienes as versatile intermediates for sulfur-containing 1,1,4,4-tetra-aryl-1,3-butadiene derivatives are described. The dithiols were prepared from cyclic polysulfides and their structure was characterized by the single-crystal X-ray diffraction analyses. Both cyclic dithioacetals and acyclic S, S’-dimethyl derivatives were prepared by facile reactions of the corresponding dithiols. The acyclic sulfur-substituted dienes exhibited electrochromic behavior in which the solution turned from colorless to dark purple under the external electric field over potentials of 0.3 V vs Fc/Fc + .