Synthesis and electrochemical polymerisation of 3′-functionalised terthiophenes: Electrochemical and spectroelectrochemical characterisation

A new terthienyl derivative, 4′-[(2,2′:5′,2″-terthien-3′-yl)methoxy]-2,2′:6′,2″-terpyridine, was synthesised in order to electrogenerate a new conducting polymer as an electrode coating suitable to complex metal ions. The characteristics of the system obtained have been defined through electrochemical and spectroelectrochemical techniques. The physical and chemical properties of 4′-[(2,2′:5′,2″-terthien-3′-yl)methoxy]-2,2′:6′,2″-terpyridine are compared with those of 3′-hydroxymethyl-2,2′:5′,2″-terthiophene, i.e. the corresponding trimer not bearing the terpyridine ligand. Under the same conditions for both monomers, both electrochemical and spectroelectrochemical tests show that 4′-[(2,2′:5′,2″-terthien-3′-yl)methoxy]-2,2′:6′,2″-terpyridine leads to the formation of a narrower molecular weight distribution, with shorter-conjugated polymer chains.