Selective cation and anion guest binding in host selenazamacrocycles

Abstract

We report selenazamacrocycle hosts that are the first system to change guest binding affinity from cation to anion depending upon macrocycle oxidation/reduction. Selective cation (Fe²⁺) or anion (BF₄⁻) binding occurs with both ions present and under identical reaction conditions. We also report the first macrocyclic complex with a Fe–Se bond.