Quinoline appended oxacalixarene as turn-off fluorescent probe for the selective and sensitive determination of Cu2+ ions: A combined experimental and DFT study

• Published in: Journal of luminescence Vol. 192; pp. 256 - 262
• Main Authors: Panchal, Manthan, Athar, Mohd, Jha, P.C., Kongor, Anita, Mehta, Viren, Jain, Vinod
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-12-2017
• Subjects: Copper ions; DFT calculations; Fluorescence studies; Host-guest interactions; Oxacalixarenes; Host-guest interactions; Copper ions; Fluorescence studies; Oxacalixarenes; DFT calculations
• ISSN: 0022-2313; 1872-7883
• DOI: 10.1016/j.jlumin.2017.06.052

A novel supramolecular fluorescent molecular probe constructed on oxacalix[4]arene allied to 8-quinoline sulfonyl chloride (DQOC) was synthesized and used for the detection of copper ions with a linear range of detection between 20nM and 1μM. 1H NMR titration and ESI-MS spectroscopic studies reflect the 1:1 complexation of the DQOC-Cu+2 complex. Furthermore, density functional theory (DFT)-based quantum mechanical calculations were used to predict the most likely structure of the cationic complex of the DQOC. In the modeled system, the oxacalix[4]arene, DQOC remains armed in the 1, 3-alternate conformation, and the Cu2+ was mainly stabilized outside the annulus and appended in between one of the quinoline substituents and oxacalix[4]arene. The detection limit of the DQOC for Cu2+ ions was found to be 0.046ngml−1. From the results of the real sample, we anticipate that the probe can be readily applied for the detection of Cu2+.
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