| Autor: |
Meena, Bashdar I., Lakk-Bogáth, Dóra, Keszei, Soma, Kaizer, József |
| Jazyk: |
English<br />French |
| Rok vydání: |
2021 |
| Předmět: |
|
| Zdroj: |
Comptes Rendus. Chimie, Vol 24, Iss 2, Pp 351-360 (2021) |
| Druh dokumentu: |
article |
| ISSN: |
1878-1543 |
| DOI: |
10.5802/crchim.112 |
| Popis: |
Hydrogen peroxide and peroxymonocarbonate anion-based bleach reactions are important for many applications such as paper bleach, waste water treatment and laundry. Nonheme iron(III) complexes, $[\mathrm{Fe}^{\mathrm{III}}(\mathrm{L}^{1-4})\mathrm{Cl}_{2}]$ with the 1,3-bis($2^{\prime}$-Ar-imino)isoindolines ligands ($\mathrm{HL}^{n}$, $n=$1–4, Ar $=$ pyridyl, thiazolyl, benzimidazolyl and N-methylbenzimidazolyl, respectively) have been shown to catalyze the oxidative degradation of morin as a soluble model of a bleachable stain by $\mathrm{H}_{2}\mathrm{O}_{2}$ in buffered aqueous solution. In these experiments the bleaching activity of the catalysts was significantly influenced by the Lewis acidity and redox properties of the metal centers, and showed a linear correlation with the $\mathrm{Fe}^{\mathrm{III}}/\mathrm{Fe}^{\mathrm{II}}$ redox potentials (in the range of 197–415 mV) controlled by the modification of the electron donor properties of the ligand introducing various aryl groups on the bis-iminoisoindoline moiety. A similar trend but with low yields was observed for the disproportionation of $\mathrm{H}_{2}\mathrm{O}_{2}$ (catalase-like reaction) which is a major side reaction of catalytic bleach with transition metal complexes. The effect of bicarbonate ions might be explained by the reduction of Fe(III) ions and/or the formation of peroxymonocarbonate monoanion, which is a much stronger oxidant and could increase the formation of the catalytically active high-valent oxoiron species. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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