Aromatic hydrazones derived from nicotinic acid hydrazide as fluorimetric pH sensing molecules: structural analysis by computational and spectroscopic methods in solid phase and in solution
| Autor: | Tomislav Benković, Vasile Chiş, Adriana Kenđel, Nives Galić, Snežana Miljanić, Darko Kontrec, J. Parlov-Vuković |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
1D and 2D NMR
FT-IR Raman UV-Vis spectroscopy fluorescence computational study fluorimetric pH sensors 010405 organic chemistry Chemistry Protonation 010402 general chemistry Photochemistry 01 natural sciences Atomic and Molecular Physics and Optics 3. Good health 0104 chemical sciences Analytical Chemistry symbols.namesake Ultraviolet visible spectroscopy Deprotonation Solid-state nuclear magnetic resonance Intramolecular force symbols Physical chemistry Raman spectroscopy Spectroscopy Instrumentation Two-dimensional nuclear magnetic resonance spectroscopy |
| DOI: | 10.1016/j.saa.2017.09.038 |
| Popis: | Structural analyses of aroylhydrazones were performed by computational and spectroscopic methods (solid state NMR, 1 and 2D NMR spectroscopy, FT-IR (ATR) spectroscopy, Raman spectroscopy, UV-Vis spectrometry and spectrofluorimetry) in solid state and in solution. The studied compounds were N'-(2, 3- dihydroxyphenylmethylidene)-3- pyridinecarbohydrazide (1), N'-(2, 5- dihydroxyphenylmethylidene)-3- pyridinecarbohydrazide (2), N'-(3-chloro-2- hydroxy-phenylmethylidene)-3- pyridinecarbohydrazide (3), and N'-(2-hydroxy- 4-methoxyphenyl-methylidene)-3- pyridinecarbohydrazide (4). Both in solid state and in solution, all compounds were in ketoamine form (form I, –CO–NH–N=C–), stabilized by intramolecular H-bond between hydroxyl proton and nitrogen atom of the C=N group. In solid state, the C=O group of 1–4 were involved in additional intermolecular H- bond between closely packed molecules. Among hydrazones studied, the chloro- and methoxy- derivatives have shown pH dependent and reversible fluorescence emission connected to deprotonation/protonation of salicylidene part of the molecules. All findings acquired by experimental methods (NMR, IR, Raman, and UV- Vis spectra) were in excellent agreement with those obtained by computational methods. |
| Databáze: | OpenAIRE |
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