Anion induced azo-hydrazone tautomerism for the selective colorimetric sensing of fluoride ion.
The design, synthesis, characterization and their anion sensing properties of two receptors capable of exhibiting azo-hydrazone tautomerism are reported. The anion sensing properties have been investigated using electronic, fluorescence and nuclear magnetic spectral studies in addition to electrochemical and visual detection experiments. Both the receptors selectively bind fluoride ion with >100 nm red-shift in the electronic spectrum and the color changes from yellow to red. The results of the spectral studies revealed that the sensing mechanism involves fluoride ion induced change of chromophore from C=N (hydrazone form) to N=N (azo form) in these receptors leading to the visible color change. Density Functional Theory calculations were conducted to rationalize the optical response of the receptors.
Department of Chemistry, Gandhigram Rural Institute (Deemed University), Gandhigram 624302, India.
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Satheshkumar
Chemistry Department, Faculty of Science, King Abdul-Aziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia; Chemistry Department, Faculty of Science, Benha University, Benha 13518, Egypt.
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El-Mossalamy
Department of Chemistry, Gandhigram Rural Institute (Deemed University), Gandhigram 624302, India.
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Manivannan
Department of Chemistry, Gandhigram Rural Institute (Deemed University), Gandhigram 624302, India.
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Parthiban
Chemistry Department, Faculty of Science, King Abdul-Aziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia.
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Al-Harbi
Chemistry Department, Faculty of Science, King Abdul-Aziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia.
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Kosa
Department of Chemistry, Gandhigram Rural Institute (Deemed University), Gandhigram 624302, India. Electronic address: drkpelango@rediffmail.com.
Kuppanagounder P
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Elango
D001391:Azo Compounds / Q000737:chemistry*; D005459:Fluorides / Q000737:chemistry*; D006835:Hydrazones / Q000737:chemistry*; D008956:Models, Chemical; D013053:Spectrophotometry / Q000379:methods
D001391:Azo Compounds; D006835:Hydrazones; D005459:Fluorides
Acenaphthenequinone; Chromophore; DFT calculation; Fluoride ion; Sensors; Tautomerism