| People | Locations | Statistics |
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| Naji, M. |
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| Motta, Antonella |
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| Aletan, Dirar |
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| Mohamed, Tarek |
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| Ertürk, Emre |
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| Taccardi, Nicola |
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| Kononenko, Denys |
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| Petrov, R. H. | Madrid |
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| Alshaaer, Mazen | Brussels |
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| Bih, L. |
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| Casati, R. |
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| Muller, Hermance |
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| Kočí, Jan | Prague |
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| Šuljagić, Marija |
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| Kalteremidou, Kalliopi-Artemi | Brussels |
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| Azam, Siraj |
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| Ospanova, Alyiya |
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| Blanpain, Bart |
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| Ali, M. A. |
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| Popa, V. |
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| Rančić, M. |
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| Ollier, Nadège |
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| Azevedo, Nuno Monteiro |
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| Landes, Michael |
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| Rignanese, Gian-Marco |
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Cunha Silva, L.
in Cooperation with on an Cooperation-Score of 37%
Topics
Publications (11/11 displayed)
- 2021Multidimensional ln-aminophthalate photoluminescent coordination polymerscitations
- 2021Decorating MOF-74-derived nanocarbons with a sandwich-type polyoxometalate to enhance their OER activity: Exploring the underestimated bulk-deposition approachcitations
- 2020Advanced framework-modified POM@ZIF-67 nanocomposites as enhanced oxygen evolution reaction electrocatalystscitations
- 2020Oxygen Evolution Reaction Electrocatalytic Improvement in POM@ZIF Nanocomposites: A Bidirectional Synergistic Effectcitations
- 2019Synthesis of Pyridyl and N-Methylpyridinium Analogues of Rosamines: Relevance of Solvent and Charge on Their Photophysical Propertiescitations
- 2016Design of a Water Soluble Fluorescent 3-Hydroxy-4-Pyridinone Ligand Active at Physiological pH Valuescitations
- 2014Novel polyoxometalate silica nano-sized spheres: efficient catalysts for olefin oxidation and the deep desulfurization processcitations
- 2014Tuning the limits of pH interference of a rhodamine ion sensor by introducing catechol and 3-hydroxy-4-pyridinone chelating unitscitations
- 2013Novel Composite Material Polyoxovanadate@MIL-101(Cr): A Highly Efficient Electrocatalyst for Ascorbic Acid Oxidationcitations
- 2013Europium Polyoxometalates Encapsulated in Silica Nanoparticles Characterization and Photoluminescence Studiescitations
- 2010Insights into electronic and structural properties of novel Pd(II) salen-type complexescitations
Places of action
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article
Synthesis of Pyridyl and N-Methylpyridinium Analogues of Rosamines: Relevance of Solvent and Charge on Their Photophysical Properties
Abstract
A series of pyridyl analogues of rosamines was prepared by employing two methodologies: (i) the conventional-heating condensation of a pyridinecarboxaldehyde with 3-(diethylamino)phenol in propionic acid, and (ii) the novel ohmic-heating assisted condensation under "on water" conditions, followed by oxidation. The 4-pyridyl substituted rosamine was further converted into the N-methylpyridinium derivative through N-alkylation using methyl iodide. The influence of the position and cationization of the nitrogen atom of the pyridyl ring in the physicochemical properties of fluorophores was investigated by H-1, C-13, N-15 NMR spectral analysis, UV/Vis and fluorescence spectroscopy, single-crystal X-ray diffraction (4-pyridyl and N-methylpyridinium derivatives) and thermal-behavior analysis. Curiously, for ethanolic solutions of 4-pyridyl and N-methylpyridinium derivatives an extinction of color and fluorescence over time was observed. This phenomenon was further studied and the data revealed that it is the result of nucleophilic addition of ethoxide ion to the central 9-position of the xanthene. The kinetics of the process is slower for the 4-pyridyl rosamine, which emphasizes the importance of the charge in the N-methylpyridinium analogue in the reactivity of the molecule towards a nucleophile agent. This phenomenon is reversible, meaning that the compounds can be rapidly recovered by decreasing the pH, opening new avenues in the sensing applications of this class of rosamines.