Schiff Base Polymers Obtained by Oxidative Polycondensation and Their Co(II), Mn(II) and Ru(III) Complexes: Synthesis, Characterization and Catalytic Activity in Epoxidation of Styrene

Abstract

In this paper, Schiff base monomers having double azomethine groups, N,N′-bis(4-hydroxybenzylidene)1,4-phenylenediamine (M1) and N,N′-bis(4-hydroxysalicylidene)1,4-phenylenediamine (M2), were prepared by a common condensation reaction between 4-hydroxybenzaldehyde and 4-hydroxysalicylaldehyde with 1,4-phenylenediamine, respectively. The new Schiff base polymers, poly(N,N′-bis(4-hydroxybenzylidene)1,4-phenylenediamine) (P1) and poly(N,N′-bis(4-hydroxysalicylidene)1,4-phenylenediamine) (P2) were synthesized from the oxidative polycondensation of monomers with NaOCl in an aqueous alkaline medium. The characterization of synthesized monomers and polymers was carried out by FT-IR, UV-Vis, 1H-NM, 13C-NMR and elemental analysis. The new polymer–metal complexes were prepared by using polymers and Co(II), Mn(II) and Ru(III) metal salts. Thermal properties of the compounds were studied by TG-DTA techniques. In addition, the catalytic properties of the polymers and their metal complexes were investigated in epoxidation reactions of styrene. The results of the catalysis studies were monitored by GC–MS.