Synthesis of 1,1,4,4-tetra-aryl-1,3-butadienes possessing sulfur substituents at 2,3-positions via dithiol intermediates and their characteristic electrochromic behaviors

Abstract

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 structures were characterized by 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 an external electric field above a potential of 0.3 V vs Fc/Fc+.