A porphyrin tetramer for a positive homotropic allosteric recognition system: efficient binding information transduction through butadiynyl axis rotation

A porphyrin tetramer 1 was newly designed and synthesized to construct a novel allosteric guest-binding system. Compound 1 has a butadiynyl rotational axis, which is expected to act as a guest-binding information transducer. In chloroform, 1 can bind bidentate amines, such as 1,3-di(4-piperidyl)propane (DPP), in an allosteric manner to produce a 1:2 1/diamine complex with a Hill coefficient of 1.9.