Ratiometric chemosensing of Mg2+ ions by a calix[4]arene diamide derivative

A new chemosensor with a phenanthroimidazole subunit based upon calix[41arene-diamide has been synthesized, and its Mg2+ -selective fluoroionophoric properties were investigated in an aqueous DMSO solution. The compound exhibited a pronounced Mg2+ -selective fluoroionophoric behavior over other physiologically relevant metal ions. A significant red shift in fluorescence emission (Delta lambda = 86 nm) provided the ratiometric determination as well as naked-eye detection of Mg2+ ions. (c) 2007 Elsevier Ltd. All rights reserved.