A facile synthesis of a novel 4-hydroxyl-3-azo coumarin based colorimetric probes for detecting Hg2+ and a fluorescence turn-off response of 3CBD to Fe3+ in aqueous environment

Two azo dyes, ( E )-3-(benzo[ d ]thiazol-2-yldiazenyl)-4-hydroxy-2 H -chromen-2-one (3CBD) and ( E )-4-hydroxy-3-(quinolin-2-yldiazenyl)-2 H -chromen-2-one (3CQD), were designed and synthesized using facile methods.