New chromogenic bis(isatin hydrazonyl)calix[4]arenes for dual recognition of fluoride and silver ions

New calixarene based dual chromogenic receptors bearing isatin hydrazone units have been synthesized and evaluated for their ion recognition potential. The synthesized molecular receptors can effectively and selectively recognize fluoride and silver ions through visible color changes and pronounced bathochromic shifts in their UV–visible spectra. NMR titration data further support the preliminary conclusions.