A highly selective fluorescent chemosensor for guanosine-5′-triphosphate via excimer formation in aqueous solution of physiological pH

A new water-soluble and fluorescent imidazolium-anthracene cyclophane 1 effectively recognizes and differentiates the biologically important GTP and ATP in 100% aqueous solution of physiological pH 7.4. Fluorescence, H-1-NMR spectra and ab initio calculations demonstrate that excimer formation and fluorescence enhancement occur upon GTP and ATP binding, respectively, through (C-H)(+)center dot center dot center dot A hydrogen bond interactions.