Cyclic Anion-Responsive π-Electronic Molecules That Overcome Energy Losses Induced by Conformation Changes.

Preorganized structures suitable for anion binding were prepared by introducing dipyrrolyldiketone BF2 complexes as acyclic anion-responsive π-electronic molecules into macrocycles. Pyrrole-inverted conformations, which typically present low stability in the case of acyclic derivatives, were obtained by covalent linkages through ring-closing olefin metathesis, exhibiting extremely high affinity for different anions.