Simple colorimetric chemosensors for detection F- ion based on phenyl urea derivatives

Abstract

Abstract Colorimetric receptors 1-[2-(4-nitrobenzylideneamino)phenyl]-3-phenylurea (R1) and 1-[2-(2-hydroxy-5-nitrobenzylideneamino)phenyl]-3-phenylurea (R2) were synthesized and characterized by elemental and spectroscopic methods. Anion sensing behaviour of ssynthesized molecules were analyzed that showed a distinct color change only when treated with fluoride ions (F-) in the naked-eye experiment also supported by electronic spectral titration methods. NMR spectral titration method confirms the hydrogen bond formation between F- with OH and NH protons of R2.