ELECTROCHEMISTRY OF RU (EDTA) COORDINATED TO PYRIDINE GROUP WITHIN THERMORESPONSIVE GEL FILMS

N-Isopropylacrylamide is copolymerized with 4-vinylpyridine and N, N'- methylenebisacryl amide. The obtained gel is swollen below 10 degrees C and shrunken above 40 degrees C in aqueous solutions. Coordination o f Ru(EDTA) to the gel immobilized on a gold electrode is investigated by means of cyclic voltammetry. Ru-III(EDTA) or Ru-II(EDTA) coordinate s to one or two pyridine rings of the gel, respectively. Ru(EDTA) coor dinated to two pyridine groups gradually dissociates to be Ru(EDTA) co ordinated to one pyridine ring during potential cycling. The D-app val ue for the swollen gel having Ru-II/III(EDTA) coordinated to one pyrid ine ring is estimated to be 20-fold larger than that for the shrunken gel. (C) 1998 Elsevier Science S.A.