New fluorescent bis-β-cyclodextrin-indolizine sensor. Synthesis and sensing ability

Abstract

(Chemical Equation Presented) The synthesis of 1,3-[bis-N-6A-deoxy-β- cyclodextrin-6A-yl-aminocabonyl]-7-pyridin-4-yl indolizine is reported. The reaction proceeds by an amidation between 6-amino-β-cyclodextrin and 1,3-[bis-(-4-nitrophenoxycarbonyl)-7-[pyridine-4-yl)] and yields the first sensor having in its structure the fluorescent indolizine and two β-cyclodextrin fragments. The sensing ability towards phenol, p-cresol and adamantan-1-ol has been evaluated by fluorescence spectroscopy. The molecular modelling study realised by MM3 and AM1 methods shows that non cooperative conformations are favoured, thus explaining that inclusion ability is not increased by such dimer, and that sensitivity is not enhanced as compared to corresponding monomelic sensors.