Electrogenerated poly(thiophenes) derivatized by bipyridine ligands and metal complexes

Abstract

The synthesis of a series of bithiophenic precursors of electrogenerated conjugated polymers functionalized by bipyridine ligands is described. The precursor structure involves two polymerizable groups attached at both ends of a bipyridine ligand and fixed at an internal β-position of thiophene via an alkylsulfanyl or alkoxy spacer. Electrochemical and optical data show that the low polymerization potential resulting from the association of 3,4-ethylenedioxythiophene (EDOT) and alkylsulfanyl or alkoxy thiophene combined with the multi-site polymerization approach allows a straightforward electrosynthesis of extensively conjugated and stable functionalized polymers. On the basis of these results, iron and ruthenium complexes of these precursors have been synthesized and electropolymerized. The analysis of the electrochemical behavior of the resulting polymers shows that they exhibit the typical electrochemical signature of both the conjugated polythiophene backbone and the immobilized metal complex.