Wydział Chemii

Katarzyna Ślusarek-Zając

Emilia Ganczar

Tadeusz Lis

Mateusz Waliczek

Marcin Stępień

2026

Angewandte Chemie - International Edition

e2275817

10.1002/anie.2275817

Naukowa

Angielski

Artykuł

Acid–base equilibria can be shifted when binding events alter the local electrostatic and hydrogen-bonding environment of an ionizable site. Implementing such binding-linked acidity changes in a discrete synthetic system would enable regulation of proton activity without changing molecular composition or solvent. Here we describe a new naphthalimide-fused analogue of cyclo[8]pyrrole in which anion recognition dramatically shifts protonation equilibria. Whereas established cyclo[8]pyrroles preferentially form globally aromatic dications, the electron-deficient macrocycle shows an unusual preference for a persistent neutral redox state, while simultaneously revealing exceptionally high Brønsted acidity in organic solvents. The neutral macrocycle retains key anion-recognition characteristics of dicationic cyclo[8]pyrroles, including strong sulfate affinity. Sulfate binding increases the effective first pK_a in DMSO by roughly four units, providing an orthosteric, anion-actuated acid switch and expanding the design space of switchable acidity beyond host–guest pK_a shifts and light-addressable photoacids.

anion receptors, Brønsted acidity, cyclo[8]pyrroles, sulfate binding, supramolecular chemistry

http://dx.doi.org/10.1002/anie.2275817

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