Zn2+ Specific Colorimetric Receptor Based on Coumarin

The receptor 1 having coumarin and thiazole as electron-deficient and -rich centers respectively acted as a colorimetric receptor selectively for Zn2+ as its chloride salt in DMSO/aq. DMSO (10:90 v/v) by exhibiting a remarkable bathochromic shifting of 120 nm in its 375 nm UV–visible absorption band. The interaction of receptor 1 with a number of metal ions ranging from s,p to d blocks as their chloride salts indicated the selectivity of the same toward Zn2+. Transmission electron microscopy (TEM) along with spectroscopic studies indicated Zn2+ triggered aggregate formation of the receptor 1 as the key step toward sensing.