JOURNAL OF INORGANIC AND ORGANOMETALLIC POLYMERS AND MATERIALS, vol.20, no.2, pp.369-379, 2010 (SCI-Expanded)
Oxidative polycondensation reaction conditions of [(2-mercaptophenyl)iminomethyl]-2-naphthol (2-MPIM-2N) were studied using oxidants such as air and NaOCl in an aqueous alkaline medium between 40 degrees C and 90 degrees C. The structure of poly-[(2-mercaptophenyl)iminomethyl]-2-naphthol (P-2-MPIM-2N) was characterized by (1)H- (13)C NMR, FT-IR, and UV-Vis spectroscopy, size exclusion chromatography (SEC), and elemental analysis. At optimum reaction conditions, the yield of P-2-MPIM-2N was found to be 78 and 82% for air and NaOCl oxidants, respectively. From SEC measurements, the number-average molecular weight (M(n)), weight-average molecular weight (M(w)) and polydispersity index (PDI) of P-2-MPIM-2N are 2900, 3500 g mol(-1) and 1.207; 2200, 2500 g mol(-1) and 1.136, for air and NaOCl oxidants, respectively. Polymer-metal complexes were synthesized by the reaction of P-2-MPIM-2N with Co(2+), Cu(2+), Zn(2+), Pb(2)+ and Cd(2+) ions. The highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), and electrochemical band gaps (E'(g)) of 2-MPIM-2N and P-2-MPIM-2N were -5.97, -2.66 and 3.31 eV and -5.82, -2.68 and 3.14 eV, respectively. The conductivity of polymer and polymer-metal complexes were determined in the solid state. Conductivity measurements of doped and undoped Schiff base polymer and polymer-metal complexes were carried out at room temperature and atmospheric pressure by the four-point probe technique using an electrometer. The conductivities of the polymer and polymer-metal complexes increased when iodine was used as doping agent.