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-1H-imidazol-2-yl)phenol (DMTP) has been designed and synthesized using nano SiO2 as catalyst. Nano SiO2 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 1H and 13C-NMR spectral studies. Proton and 13C 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 Fe3+ metal ion. Addition and increasing concentration of Fe3+ ions into DMTP results excellent fluorescence quenching. Other cations, including Ca2+, Al3+, K+, 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.