Synthesis and characterization of thermally stable and environmental friendly 1: 2 metal complexed azo colorants from 2-(4-hydroxyphenyl)-1H-isoindole-1,3(2H)-dione

4-Aminophemol was reacted with phthalic anhydride to get (3) and used as coupling component in the preparation of o,o'-dihydroxy azo dyes which were subsequently converted into 1:2 metal complex colorants; the metals used were Fe, Co, and Cr. The structure of metal complexes were confirmed by AAS. The heat stability and draw down properties have been evaluated