Abstract

Exploiting click reaction as the key step, azo-coupled macrocyclic colorimetric chemosensors 4a and 4c were synthesized for metal ion sensing. Among metal ions examined, only Hg2+ can induce color change from orange to pale yellow detectable by the naked-eye for both sensors. The bind mode of the complex was established by spectrophotometric and NMR titrations.

Keywords: Click reaction, colorimetric sensors, Hg2+ detection, macrocyclic chromoionophores, naked-eye detection, chromogenic receptors, aza-macrocyclic system, p-nitroaniline, N, N-di-2-propynyl aniline, acetonitrile, UV-vis spectrophotometry, colorimetric chemosensors, hypsochromic shift, NMR, NNNO tetradentate ligand