A new terthienyl derivative, 4-[(2,2:5',2"-terthien-3'-yl)methoxyl-2,2':6',2"-terpyridine, was synthesised in order to clectrogenerate 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 spectroelectrochernical techniques. The physical and chemical properties of 4'-[(2,2':5'.2"-terthien-3'-yl)methoxy]2,2': 6',2"-terpyfi dine 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 spectroelectrochentical tests show that 4'-[(2,2':5',2"-terthien-3'yl)methoxyl-2,2':6',2"-terpyfidine leads to the formation of a narrower molecular weight distribution, with shorter-conjugated polymer chains. (c) 2006 Elsevier Ltd. All rights reserved.