Controlling transport of ion pairs by a light-responsive heteroditopic azobenzene carrier

Precise and stimuli-controllable transport of charged and neutral guests is a hallmark of cellular processes. Although ion transport has been mimicked with artificial carriers, no such systems are known for electrically neutral ion pairs. We have engineered an artificial carrier (1) that demonstrates a regulated binding and transport of ion pairs dependant on the photo-controlled translocation of the cation and anion binding domains. The NMR and electrochemical experiments supported by DFT calculations show that UVA-generated V-shaped cis-1, featuring ion binding domains close to each other, exhibits an unprecedented 74-fold higher extraction rate of ion pairs relative to the native trans-1.