Colorimetric and fluorogenic anion sensors of 2′-(p-nitrophenyl)-imidazol[4′,5′-f]-1,10-phenanthroline[5,6-f] and its complex of

Abstract

2′-(p-nitrophenyl)-imidazol[4′,5′-f]-1,10-phenanthroline[5,6-f] (1) and its complex (2) were synthesised and studied for the anion sensing by UV–vis, fluorescence and 1H NMR titration experiments. Compounds 1 and 2 exhibited obviously different changes between reactions with AcO− , F− , and with other halogens, i.e. Cl− , Br− , I− , in any of the UV–vis, fluorescence and 1H NMR titration spectra in DMSO experiments. With an 89 nm red shift, 1 was convenient to be employed to detect anions with the naked eye. Complexed with the electron withdrawing metal ion, 2 had the stronger interaction with anions to be detected than 1 had.