Ion‐Selective Crown Ether Dyes

Abstract

Cation-selective color changes can be accomplished in dyes in which a heteroatom of the chromophore participates as a donor center in complex formation by a crown ether. The greatest effect (Δλ ≈ 120nm) is observed with the combination (1), M⊕ = Ba2⊕ (2I− as counterion).