Synthesis of π-Conjugated 2,2:6′,2″-Terpyridine-Substituted Oligomers Based on 3,4-Ethylenedioxythiophene

Abstract

Dissymmetric π-conjugated monomers and oligomers incorporating 3,4-ethylenedioxythiophene (EDOT) units and bearing terpyridine end groups were synthesized in good yields through Vilsmeyer-Haak formylation followed by a reaction with 2-acetylpyridine in basic media or, for the longest oligomers, direct C-H bond arylation. They have a low HOMO-LUMO gap and are easily oxidized at low potentials. Upon complexation with cobalt(II) and iron(II) they yield new hybrid materials that can be used in various applications ranging from photovoltaics to spintronics.