A calixarene-based fluorogenic reagent for selective mercury(II) recognition

The first calixarene-based fluorogenic Hg(II)-selective extractant, 5,11,17 ,23-tetrakis(1,1-dimethylethyl)-25,27-bis(N-(5-dimethylaminonaphthalene-1-s ulfonyl)carbamoylmethoxy)-26,28-dimethoxycalix[4]arene (2), is reported. In solvent extraction front aqueous acidic solutions (HNO3), 2 exhibits excel lent selectivity for Hg(II) over a wide range of transition, alkali, and al kaline earth metal cations, Quenching of its fluorescence due to Hg(II) coo rdination is unaffected by the presence of 100-fold excesses of alkali meta l cations, alkaline earth metal cations, Ag(I), TI(I), Cd(II), Co(II), Cu(I I), Mi(II), Pb(II), Pd(II), Zn(II), or Fe(III).