Enhancements in the Electron-Transfer Kinetics of Uranium-Based Redox Couples Induced by Tetraketone Ligands with Potential Chelate Effect
| Autor: | Yoshiyuki Nakamura, Hironori Sato, Kenji Shirasaki, Isamu Satoh, Yoshinobu Shiokawa, Tomoo Yamamura, Hiroshi Tomiyasu |
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| Rok vydání: | 2007 |
| Předmět: |
Acetylacetone
Metal ions in aqueous solution Kinetics Inorganic chemistry chemistry.chemical_element Uranium Redox Surfaces Coatings and Films Electronic Optical and Magnetic Materials Electron transfer chemistry.chemical_compound General Energy Monomer chemistry Chelation Physical and Theoretical Chemistry |
| Zdroj: | The Journal of Physical Chemistry C. 111:18812-18820 |
| ISSN: | 1932-7455 1932-7447 |
| Popis: | Acetylacetone shows dissociative electron transfer when it is complexed with metal ions. In an effort to improve the kinetics of electron transfer of uranium-based complexes for application to a redox-flow battery, improvement by dimerization of acetylacetone into tetraketones with potential chelate effect is examined and discussed quantitatively. For the monomer acetylacetone, electron transfer of uranium complexes reveals an ECE mechanism and an inner-sphere reaction on the electrode surface. By using tetraketones, 8-oxo-2,4,12,14-tetraoxapentadecane and m-bis(2,4-dioxo-1-pentyl)benzene, the electron transfer of tetraketones with U(VI)/U(V) and U(IV)/U(III) shows rapid kinetics based on the E mechanism. In clear contrast to U(acac)4, the electrochemically reduced species of the U(IV) complex with tetraketone is stable during potential cycling. These results are also supported by NMR of tetraketones with U(VI) and U(IV); each acetylacetone site to uranium atom is stable at −40 ∼ +40 °C. The results demon... |
| Databáze: | OpenAIRE |
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