A competitive sensing system based on cyclobis(paraquat-p-phenylene) and a new beta-cyclodextrin-tetrathiafulvalene derivative

We report the synthesis of 4,5-di(ethylthio)-4'-[6-deoxy--cyclodextrin-6-yl-aminocarbonyl]-tetrathiafulvalene (beta-CD-DET-TTF) and its inclusion abilities towards cyclobis(paraquat-p-phenylene) (CBPQT(4+)) and 1-naphthol. The structure of the synthesised compound has been established by mass spectrometry and H-1 NMR spectra combined with a theoretical MM3 and AM1 study. The sensor affords a charge transfer (CT) complex with the CBPQT(4+) and is able to include 1-naphthol in the cyclodextrin cavity. The complexes were characterised experimentally by UV-vis spectroscopy and simulated by a MM3 docking procedure. The sensing ability of the beta-CD-DET-TTF/CBPQT(4+) complex towards 1-naphthol has been investigated by a competitive spectral method.