Design and synthesis of an ortho-phenylenediamine-based open cleft: a selective fluorescent chemosensor for dihydrogen phosphate

A new ortho-phenylenediamine-based open fluorescent cleft 1 has been designed and synthesized. The open cleft selectively recognizes tetrabutylammonium dihydrogen phosphate in CH3CN. The anthracene emission of 1 is significantly decreased upon the sensing of dihydrogen phosphate (H2PO4-) in CH3CN. The anion binding properties of 1 were evaluated by 1H NMR, UV-vis, and fluorescence spectroscopic methods.