Fluorescence tuning of 2-(1H-Benzimidazol-2-yl)phenol-ESIPT process

Catalytic synthesis of potential chemosensor 2-(1H-Benzimidazol-2-yl)phenol (HBYP) has been prepared by three components cyclization reaction. It can behaves as a selective fluorescent sensor for the detection of Fe3+ metal ion. HBYP has been characterized by 1H NMR, 13C NMR, mass spectral studies and elemental analysis. Single crystal XRD analysis has been carried out to confirm the structure of HBYP and it shows the imidazole ring is essentially planar and monoclinic crystal. Addition and increasing concentration of Fe3+ ions into HBYP results dramatic fluorescence quenching. Other cations, including Ca2+, Co2+, Ni2+, Cd2+, Pb2+, Zn2+ and Mg2+ had little influence in the fluorescence intensity. Surprisingly reversible fluorescence enhancement has been observed with the addition of H3PO4 due to the deactivation of iron complex.