A novel Schiff base-containing phthalocyanine and its azo dye-substituted analogue: The effect of pH on colour

Abstract

There are many studies in the literature devoted to the synthesis of phthalocyanines substituted with Schiff bases and azo dyes and their particular properties. However, the comparison of spectral properties of these analogue compounds has not been investigated up to now. Therefore, a new eugenol group-bearing Schiff base-substituted zinc(II) phthalocyanine compound was synthesised and characterised and its UV/Vis spectral properties were compared with its azo dye analogue at different pH. It was determined that the azo dye analogue showed more pronounced spectral changes than the Schiff base-substituted phthalocyanine, depending on pH.