Synthesis and crystal structure of imidazole containing amide as a turn on fluorescent probe for nickel ion in aqueous media. An experimental and theoretical investigation

•Imidazole containing amide fluorescent probe was designed and synthesized.•The probe was characterized by spectral and single crystal XRD studies.•The probe acts as a selective and sensitive chemosensor for Ni2+ ions.•Existence of Ni2+ ion in real water samples was evaluated.

Imidazole containing amide fluorescence probe (PAIC) for Ni2+ was designed and successfully synthesized in good yield by reaction between 1-methyl-1H-imidazole-2-carboxylic acid and l-phenylalanine methyl ester. The probe was characterized by FTIR, 1H NMR, ESI-MS, UV–vis and fluorescence spectroscopy. Single crystal XRD analysis reveals that PAIC crystallizes in a monoclinic crystal lattice system with the space group of P21/n. Chemosensor property of PAIC was tested against different metal ions by UV–vis and fluorescent techniques in aqueous medium. Test results show that PAIC has high selectivity for Ni2+ compared to other metal ions (Na+, K+, Ca2+, Ag+, Co2+, Cu2+, Fe2+, Fe3+, Hg2+, Mn2+, Zn2+ and Pb2+). Time-dependent density functional theory (TD-DFT) and configuration interaction singles (CIS) calculations were carried out to understand the sensing mechanism. The practical applicability of PAIC was tested in real water samples.

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