RESUMO
Calixpyrenes, calix[4]arenes incorporating one or two pyrene moieties as a part of their hydrophobic cavities, have been prepared and fully characterized. Distally di-O-propoxy diether of the calix dipyrene, which exists in the pinched cone conformation with nearly parallel pyrene moieties, demonstrates strongly enhanced binding of an organic cation (N-methylpyridinium) compared with the analogous diethers of the parent calix[4]arene.
RESUMO
We report the synthesis of a series of the oxygen-depleted conjugated 5,5'-Bicalix[4]arene compounds bearing various substituents at the terminal positions of the conjugated chain and their fluorescence response to the presence of a cationic N-methylpyridinium guest. The complexation of this cation within the bicalixarene cavity results in the fluorescence quenching, with the host molecules bearing electron-donating groups demonstrating a stronger fluorescence response. These results show the importance of the electronic effects on the host-guest complexation within the hydrophobic calixarene scaffolds.
