Synthesis and properties of fully-conjugated indacenedithiophenes

Abstract

The synthesis and characterization of four fully-conjugated indacenedithiophenes (IDTs) are disclosed. In contrast to anthradithiophenes, regioselective synthesis of both <i>syn</i> and <i>anti</i> isomers is readily achieved. Thiophene fusion imparts increased paratropic character on the central indacene core as predicted by DFT calculations and confirmed by ¹H NMR spectroscopy. IDTs exhibit red-shifted absorbance maxima with respect to their all-carbon analogues and undergo two-electron reduction and one-electron oxidation.