An electroactive polymer film on a mercury electrode based on a thallium macrocyclic polyether complex

Films of a copolymer of 4-vinylbenzo-15-crown-5 and (3-methacryloxypropyl)trimethoxysilane were formed and cross-linked on mercury electrodes by solution evaporation followed by exposure to moist HC1 vapor. The films in-partition ions complexed by the polyether crown, such as thallium(I) from acetonitrile solution. After partitioning and transfer of the coated electrode to a thallium-free solution, electrochemical waves due to reduction of crown-complexed thallium to mercury amalgam, and the reverse, can be observed. In the presence of thallium in the solution, both crown-complexed and free thallium waves appear. Many monomolecular layer equivalents of crown-complexed thallium react in a cyclic voltammogram, and it is proposed that the thallium migrates to the electrode by hopping between crown sites.