Highly selective colorimetrie sensor for Zn~(~(2+)) based on hetarylazo derivative

摘要

An intensely colored hetarylazo derivative 1 possessing thiadiazole derivative as diazo component and m-aminoacetanilide based coupling component has been synthesized and demonstrates a highly selective color change from red to faint orange upon sensing of Zn~(2+). Other cations of the same group; Cd~(2+) did not interfere in the sensing process; however, Hg~(2+) interfered only at very high concentrations but depicted interesting sensing behaviour of its own. Other commonly occurring cations such as Ca~(2+), Mg~(2+) and Cu~(2+) did not respond to the sensing event. The pH stability of the azo derivative offers additional advantage in the sensing process.