Molecular simulation of a fluorescent sensor of 2-(1-H-benzoimidazole)-N-phenylcarbotiamide for selective detection of Ni²⁺ in aqueous media

ABSTRACT

In this computational study, 2-(1-H-benzoimidazole)-N-phenylhydrazine carbutiamide (L sensor) was reported as a highly sensitive nickel ion optical sensor. To investigate the selectivity of the ligand for metal ions, the structure of its complexes with different ions was optimised using the density functional theory (DFT) B3LYP/6-311G* (d,p) levels in solution phase (CPCM). Adsorption energy and cohesive energy were obtained in the presence of Ni²⁺ ions, respectively, −70.85 and 141.22 K cal/mol, which were the highest value obtained in the presence of cations. Electronic properties such as energy gap of metal ion complex with ligand, charge transfer between metal ion and ligand were studied and showed that the narrowest gap energy and highest charge transfer occurred between Ni²⁺ ion and ligand; so that the energy gap of the sensor decreased by 86% in the presence of Ni²⁺ ion. The optical properties of metal ion complexes with L-sensors were calculated and it was shown that the absorption of Ni²⁺ on the L-sensor changes its emission fluorescence to higher wavelengths and increases its intensity. Finally, using the QTAIM theory, it was determined that the N₁₁ and N₁₈ atomic basins are most sensitive to the presence of Ni²⁺ ion.

KEYWORDS:

• DFT study
• QTAIM
• Optical sensor
• 2-(1-H-benzoimidazole)-N-phenylhydrazine carbutiamide

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Funding

This study has no funding sponsor.