The synthesis and characterisation of planar oligophenol with Schiff base substitute

Abstract

In this study, the oxidative polycondensation reaction conditions of 2- p-tolylazomethinephenol (TAP) with air oxygen and sodiumhypochloride (NaOCl) were studied in an aqueous alkaline medium between 50 and 90 °C. The structure and properties of the products were studied by chemical and spectra analyses. TAP was converted to ditrimers (15–67%) by oxidised in an aqueous alkaline medium. The number average molecular weight ( M n), mass average molecular weight ( M w) and polydispersity index (PDI) values were found to be 6780, 7660 and 1.13, respectively. A part of the azomethine (CHN) group oxidised to carboxylic group (–COOH) during the polycondensation reaction. Thus, reaction product which is oligo-2- p-tolylazomethinephenol (OTAP), involves tolylazomethine and carboxylic (–COOH) (0.5–20%) groups. Besides, oligomer–metal complexes of OTAP with Cu(II), Zn(II), Co(II) and Pb(II) were synthesised and the structure and properties were studied. Antimicrobial activities of the oligomer and its oligomer–metal complexes have been tested against L. monocytogenez, Bacillus brevis, P. vulgaris, E. coli, B. megaterium, M. luteus, B. cereus, K. pneumoniae, M. smegmatis, S. thermophilus, S. aureus, E. aeroginosa and Torulopsis holmii. Also, DTA and TG analyses were shown to be stable for OTAP and its oligomer–metal complexes against thermooxidative decomposition.