Two-step modulation of ion recognition using a bis(saloph)-macrocyclic host having a 24-crown-8-like cavity

Abstract

Precise modulation of cation binding affinity was accomplished by the efficient two-step conversion of a newly synthesized macrocyclic ligand H₄L² having a 24-crown-8-like cavity and two saloph moieties. The conversion of H₄L² into L²Ni₂ resulted in a 120-fold enhancement in the binding affinity towards Cs⁺. The electrochemical reduction of L²Ni₂ further enhanced the recognition ability by 3 orders of magnitude.