Two novel fluorescent calix[4]arene derivatives with benzoazole units in 1,3-alternate conformation for selective recognition to Fe3+ and Cr3+

Two novel fluorescent calix[4]arene derivatives 1a and 1b with benzoxazole or benzothiazole units in 1,3-alternate conformation have been synthesized and characterized by IR, 1H NMR, 13C NMR and MS. Their complexation properties to different heavy and transition metal ions have been studied by UV–vis spectroscopy and fluorescence spectrometer. Compounds 1a and 1b show selective recognition to Fe3+ and Cr3+.