An Anthracene‐Based Fluorescent Sensor for Transition Metal Ions

Abstract

Recognition of cations by fluorescence quenching or enhancement has previously been limited to d0 and d10 cations. The fluorescent sensor 1 recognizes CuII and NiII ions in a pH-controlled complexation, in which the amide groups are deprotonated and the fluorescence of the anthracene group is quenched. ZnII and other divalent ions earlier in the 3d series (e.g. MnII and CoII) are not recognized by 1. Since only CuII is chelated by 1 at pH 7, CuII and NiII can be distinguished.