Synthesis, characterisation, solvatochromic behaviour and thermal decomposition kinetics of novel polyazo dyes containing amide group and their transition metal complexes

Abstract

The present study describes the synthesis of two new azo dyes which possess azo and amide group by general diazo-coupling reaction of 2-Amino-4-chlorophenyl phenyl and 8-Amino-2-naphthol with Naftol AS used as coupling compound. Additionally, the homopolymers of the obtained azo dyes were synthesised by oxidative polycondensation reaction. Then, Ag+1 and Cu+2 metal complexes of both monomer and polymer were synthesised. The molecular structures of the newly synthesised compounds were confirmed by different spectroscopic techniques such as H-1 NMR, C-13 NMR, FT-IR, UV-vis, SEM, TGA, and powder XRD techniques. The X-ray diffraction pattern of the synthesised compounds indicated that the compounds had amorphous and crystalline characters. The solvatochromic behaviours of all compounds were evaluated at room temperature in seven solvents having different polarities. The obtained results showed that the absorption peaks of polymers are red shifted compared to monomers. The thermodynamic parameters of all compounds were calculated from TGA curve employing the Coast-Redfern and Horowitz-Metzger methods. (C) 2018 Elsevier B.V. All rights reserved.