Preparation and properties of a linked porphyrin–cyclodextrin

Publisher Website
Google Scholar
Abstract
The synthesis of the linked porphyrin–cyclodextrin 3 and its zinc complex 4 is described and their characterization by 1H nmr, l3C nmr, circular dichroism, ultraviolet, and infrared spectroscopy is reported. The linked porphyrin–cyclodextrin compounds exhibited perturbed electronic absorption and emission spectra which are consistent with their adopting two conformations, one extended with little interaction between the porphyrin and cyclodextrin, and the other folded with the cyclodextrin weakly complexed to the porphyrin. Quenching of the porphyrin excited state of 3 by benzoquinone was examined by measurement of the fluorescence lifetime as a function of quinone concentration; the results suggest that the porphyrin excited state can be quenched intermolecularly by benzoquinone and also intramolecularly by quinone complexed within the cyclodextrin cavity.