Schiff base substitute polyphenol and its metal complexes derived from o-vanillin with 2,3-diaminopyridine:: synthesis, characterization, thermal, and conductivity properties

Poly-2,3-bis[(2-hydroxy-3-methoxyphenyl)methylene]diamino pyridine (PHMPMDAP) that a new Schiff base polymer has been synthesized and characterized by spectroscopy, elemental, and thermal analyses techniques. This azomethine polymer was found to form complexes readily with Cu(II), Zn(II), Co(II), Pb(II), and Fe(II). From IR and UV-Vis studies, the phenolic oxygen and imine nitrogen of the ligand were found to be the coordination sites. Thermogravimetric analysis (TGA) data indicate the polymer to be more stable than the monomer. The structure of the polymer obtained was confirmed by FT-IR, UV-ViS, C-13-NMR, and H-1-NMR. Characterization was undertaken by TGA, size exclusion chromatography (SEC), and solubility tests. Also, electrical conductivities of PHMPMDAP and polymer-metal complexes are measured by four probe technique. Copyright (C) 2008 John Wiley & Sons, Ltd.