Inclusion Properties of a New Metallo-Porphyrin Dimer Derived from a Calix[4]arene: Tweezers for C 70

Abstract

For the selective binding of the fullerence C 70 , we report here on the inclusion properties of a novel metallo-porphyrin dimer 1 which entails the functionalization of the basic supramolecular frame of a calix[4]arene. First, the electrochemical property of 1 was evaluated by a voltammetric method. The redox potential for reduction is m 0.46 V vs. Fc/Fc + , and those for the first and second oxidation are 0.14 V and 0.32 V vs. Fc/Fc + , respectively. These results show two porphyrin moieties of 1 are essentially unperturbed each other. Second, the selectivity factor of C 70 for 1 is remarkably large as compared with competing C 60 , because evidence for the formation of the complex came from 1 H NMR and fluorescence spectroscopic studies. In any event, the present work shows two porphyrin groups of 1 serve as tweezers to capture C 70 by two-point fixation. porphyrin supramolecular chemistry fullerene redox potential tweezers calixarene