Dynamically switchable porphyrin-based molecular tweezer for on - off fullerene recognition

Herein, a novel molecular tweezer based on 2,2 ' -bipyridine-bridged porphyrin subunits was constructed for efficient fullerenes recognition. The syn conformation of the molecule, which was obtained by Zn( II ) coordination, gives rise to a proper cavity to interact with fullerene guests to form a stable 1:1 complex in toluene solution. It exhibits distinct binding selectivity towards C 60 over C 70 . Moreover, the fullerene recognition capacity can be adequately suppressed by importing H 2 PO 4 - to competitively capture Zn( II ) along with syn-anti conformational conversion. Subsequently, the molecular tweezer regenerated to bind the fullerene by introducing the Ca 2 + into the system. Significantly, the association -disassociation process can be switched reversibly and repeatedly. (c) 2024 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.