Effect of amino anilines on the fluorescence of coumarin derivative
Autor: | Lokesh A. Shastri, Jagadish S. Kadadevarmath, Lakkanna S. Chougala, Rajashekhar F. Bhajantri, Netravati Khanapurmath, Manohar V. Kulkarni, J.M. Nirupama |
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Rok vydání: | 2019 |
Předmět: |
Quenching (fluorescence)
Chemistry Biophysics 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Electrochemistry Photochemistry Coumarin 01 natural sciences Biochemistry Fluorescence Atomic and Molecular Physics and Optics 0104 chemical sciences Gibbs free energy Electron transfer symbols.namesake chemistry.chemical_compound Excited state Proton NMR symbols 0210 nano-technology |
Zdroj: | Journal of Luminescence. 208:164-173 |
ISSN: | 0022-2313 |
Popis: | The effect of stereo electronic factors of amino anilines such as ortho-phenylenediamine (OPD) and para-phenylenediamine (PPD) on the fluorescence of 5,6-benzo-4-azidomethyl coumarin (5BAMC) in polar aprotic and polar protic solvents has been studied. From UV absorption and 1 H NMR studies, observed blue shift in the presence of PPD is due to H-bonding with 5BAMC. Fluorescence quenching studies indicate the role of static and dynamic quenching mechanisms for both the quenchers and larger quenching efficiency of PPD than OPD. The sphere of action static quenching and finite sink approximation models reveal static effect in the excited state and diffusion limited bimolecular quenching reactions. Electrochemical analysis indicates that quenching efficiency of PPD is more than OPD based on the magnitudes of free energy change for electron transfer. Binding equilibria analysis confirms that the magnitude of binding between PPD and 5BAMC is stronger compared to OPD. It is also noticed that the binding between PPD and 5BAMC in polar protic solvents is stronger than that in aprotic solvents. Lastly, from the magnitudes of thermodynamic parameters, interaction between PPD and 5BAMC is hydrophobic and spontaneous. Thus from the present investigation, it is concluded that the separation between two –NH2 groups in amino anilines plays role in their interaction with coumarin derivative 5BAMC. |
Databáze: | OpenAIRE |
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