An integrated experimental and quantum chemical study on the complexation properties of (9′-fluorene)-spiro-5-hydantoin and its thioanalogue
| Autor: | Neyko Stoyanov, Marin Marinov, Petja Marinova, Anife Ahmedova |
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| Rok vydání: | 2016 |
| Předmět: |
Denticity
Chemistry Organic Chemistry Ab initio Hydantoin Thio 02 engineering and technology Fluorene 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Analytical Chemistry law.invention Inorganic Chemistry chemistry.chemical_compound Deprotonation Computational chemistry law 0210 nano-technology Electron paramagnetic resonance Spectroscopy Derivative (chemistry) |
| Zdroj: | Journal of Molecular Structure. 1108:602-610 |
| ISSN: | 0022-2860 |
| DOI: | 10.1016/j.molstruc.2015.12.018 |
| Popis: | The reactivities of (9′-fluorene)-spiro-5-hydantoin and its thio-analogue with Cu(II) were studied in different reaction conditions and the formed products were characterized by spectroscopic methods (IR, NMR and/or EPR). It was found that unlike the 2,4-dithio- analogue, both the (9′-fluorene)-spiro-5-hydantoin and its 2-thio derivative form Cu(II) complexes only in presence of a strong base. We identified the coordination mode of the ligands and the structure of the complexes through geometry optimization of different models and calculations of the corresponding spectroscopic parameters using ab initio quantum chemical methods. The comparison between the experimental and the theoretical data suggested monodentate coordination of the fluorene-hydantoin ligands after deprotonation of one amido group. Additional confirmations of this proposition were obtained from the experimental and DFT-calculated EPR parameters (g-factor and A-tensor), which allowed for determination of the most probable geometry of the complexes. We further employed the quantum chemical methods to explain the observed differences in the complexation abilities of variously spiro-5-substituted thio- and dithio-hydantoins, accounting for the structural effects on the electron density and acidity of the hydantoin ring. |
| Databáze: | OpenAIRE |
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