A Dimeric Bis(melamine)‐Substituted Bispidine for Efficient Transmembrane H⁺/Cl⁻ Cotransport

Abstract

A 3,7‐diazabicyclo[3.3.1]nonane linking to two melamines is a unique transmembrane H+/Cl− carrier. In the solid state, the V‐shaped compound forms a HCl‐bound zig‐zag network through cooperative protonation and hydrogen bond interactions. In the lipid membrane, the receptor forms a dimeric self‐assembly involving multiple H+ and Cl− leading to the efficient transport of the acid. The pH‐dependent Cl− efflux observed for the compound was rationalized based on a gradual protonation model that confers an active transmembrane carrier at physiological pH.

Mechanosensitive Oligodithienothiophenes: Transmembrane Anion Transport Along Chalcogen‐Bonding Cascades

“…The creation of synthetic transport systems has attracted scientific attention since decades . This fascination originates from the importance of ion transport across lipid bilayer membranes in biology and the molecular complexity, variability, and beauty with which this most challenging process is achieved.…”

“…This fascination originates from the importance of ion transport across lipid bilayer membranes in biology and the molecular complexity, variability, and beauty with which this most challenging process is achieved. Until today, there is much interest in transport mechanisms, particularly synthetic ion channels but also mobile carriers and transporters . However, since the appearance of the first operational systems, ion selectivity and particularly the responsiveness to physical and chemical stimulation emerged as key challenges in the field.…”

“…Privileged scaffolds for the construction of synthetic transport systems include rod‐shaped oligomers, helical foldamers, π stacks, macrocycles such as cyclodextrins, crown ethers, pillararenes, calixarenes, cucurbiturils or G quartets, small monomers such as steroids and large architectures including metallorganic polyhedrons and DNA origami …”

“…The contact between synthetic transport systems and cations is usually established by coordination to lone pairs, whereas hydrogen bond donors are mostly used to transport anions . Cation‐ π interactions have been introduced as an attractive alternative at a time when they were still considered to account also for potassium selectivity in neural channels .…”