2-(4,5-Dimethyl-1-m-tolyl-1H-imidazol-2-yl)phenol as Efficient Chemosensor for On–Off Fluorescence System: Catalytic Synthesis and NMR Spectral Studies

An efficient chemosensor 2-(4,5-dimethyl-1- m -tolyl-1 H -imidazol-2-yl)phenol (DMTP) has been designed and synthesized using nano SiO 2 as catalyst. Nano SiO 2 exhibited remarkable catalytic activity with respect to the reaction time, amount of catalyst and vast range of substrates usage. Synthesized compounds have been characterized by 1 H and 13 C-NMR spectral studies. Proton and 13 C chemical shift of the synthesized compounds have been calculated. DMTP has been used to construct highly sensitive fluorescent chemosensor for sensing of metal ions. It can behave as a selective fluorescent sensor for the detection of Fe 3+ metal ion. Addition and increasing concentration of Fe 3+ ions into DMTP results excellent fluorescence quenching. Other cations, including Ca 2+ , Al 3+ , K + , Cd 2+ , Pb 2+ , Zn 2+ and Mg 2+ had little influence in the fluorescence intensity. Surprisingly reversible fluorescence enhancement has been observed with the addition of H 3 PO 4 due to the deactivation of iron complex.