A beta-to-beta 2,5-thienylene-bridged cyclic porphyrin tetramer: its rational synthesis and 1:2 binding mode with C-60

A beta-to-beta 2,5-thienylene-bridged cyclic porphyrin tetramer was rationally synthesized via a concise synthetic route. The tetraporphyrin exhibits a positive cooperative binding ability to C-60 and demonstrates a new potential of the nonplanar, distorted cyclic porphyrin arrays.