Synthesis of Tetra(3-thienyl)biphenoquinone and its Charge Transfer Complex with Perylene

摘要

Tetra(thienyl)biphenoquinones were designed and synthesized. An oxidative coupling of 2,6-bis(3-thienyl)phenol with PbO2 in acetic acid afforded the corresponding biphenoquinone along with 2,6-bis(3-thienyl)-p-benzoquinone. This biphenoquinone showed properties characteristic of a -expanded quinone, that is, positively shifted reduction potential and light absorption in the visible region. In contrast to kinetically protected biphenoquinones with bulky substituents at the ortho-positions of carbonyls, the title compounds take a planar structure because of the small steric repulsion of the five-membered thiophene rings. Its charge transfer complex with perylene is characterized by a well-overlapped mixed stack.