Synthesis and analytical application of the complexes of 4-methylesculetinazo compounds with some transition metal ions

The solid complexes of Mn2+, Fe3+, Co2+, Ni2+ and Cu2+ with su; azo compoun ds based on 8-arylazo-6,7-dihydroxy-4-methylcoumarin have been synthesized and characterized by elemental aid thermal analysis, magnetic susceptibilit y, molar conductance as well as IR spectroscopy, where it is found that met al ions are surrounded by coordinated water molecules and one ligand molecu le bonded in a bidentate O and N fashion in the case of ligand 1 and in tri dentate ONO fashion in the case of all the remaining ligands forming a coor dination number of six in all cases. The potentiality of the prepared azo c ompounds as new chromophoric reagents for the spectrophotometric determinat ion of the metal ions is studied by extensive investigation of the optimum conditions favouring the formation of coloured complexes in solution.