Synthesis and cooperative guest binding of tetrameric porphyrin macrocycle

Abstract

A new family of macrocyclic host molecules that possess two bisporphyrin clefts was synthesized. The tetrameric porphyrin macrocycle provides the two guest binding sites in which two electron‐deficient aromatic molecules are encapsulated through donor‐acceptor and π‐π stacking interactions. The tetrameric porphyrin macrocycle showed positive cooperativity, whereas the nonmacrocyclic analog did not. The preorganization concept drives positive cooperativity, which is directed by the entropy benefit to macrocyclization.