SYNTHESIS, CHARACTERIZATION AND ELECTROCHEMICAL POLYMERIZATION OF 8 TRANSITION-METAL COMPLEXES OF 5-AMINO-1,10-PHENANTHROLINE

The ability to prepare polymer films on the surface of glassy carbon e lectrodes (GCEs) by electrochemical polymerization of transition-metal complexes of 5-amino-1,10-phenanthroline (aphen) was investigated. Ei ght different metal ions (Mn-II, Fe-II, Co-II, Ni-II, Cu-II, Zn-II, Ru -II and Os-II) were studied. A simple and rapid method for the synthes is of the complexes with Mn-II, Co-II, Ni-II, Cu-II and Zn-II was also elaborated. The surface coverage obtained through electrochemical pol ymerization of the complexes on the GCEs can be related to the redox p otential of the metal. The iron(II) and ruthenium(II) complexes genera ted the greatest polymer film surface coverages (approximate to 10(-8) mol cm(-2)), followed by the osmium(II) and cobalt(II) complexes (app roximate to 10(-9) mol cm(-2)). Electrochemical polymerization studies with aphen, 5-nitro-1,10-phenanthroline (nphen) and the metal complex [Fe(nphen)(3)](2+) provided further evidence that the oxidative elect ropolymerization mechanism for these complexes is initiated by sweepin g through the oxidative potential of the aphen ligand (+1.35 V vs. Ag- AgCl).