A new fluorogenic calix[4]arene N-dansylcarboxamide in the cone conformation for selective optical recognition of mercury(II)

A novel fluorogenic calix[4]arene dansylcarboxamide in the cone conformation has been synthesized as the disodium salt and employed in optical recognition of mercury(II). In extraction from aqueous solutions with high content of competing Na+ (CNa+ ∼0.1 M; pH 5.0, acetate buffer) into CHCl3, the fluoroionophore allowed for detection of 8.0 × 10−7 M Hg2+ (1:1 complex; K ex app = 2.6 × 10 4 ) with high selectivity over many other relevant metal ions.