Synthetic ion channels.

The objective of this historical review is to recall the development of the field of synthetic ion channels over the past three decades. The most inspiring and influential breakthroughs with regard to structure and function are brought together to give the general reader an easily accessible understanding of the field. Pioneering work in the 1980s is followed by the golden age in the 1990s with structures emphasizing crown ethers, calixarenes, and peptide mimetics. Following the emergence of questions concerning specific functions such as ion selectivity, voltage gating, ligand gating and blockage, and with π-stacks, metal-organic scaffolds, and DNA origami, a new wave of innovative structures has emerged. The perspectives outline promising directions and major challenges waiting to be addressed.