Some dicopper complexes of benzimidazole-containing ligands
| Autor: | Sung M. Wang, Ji R. Tzou, Yuan M. Lou, Norman C. Li |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Benzimidazole
Molecular Structure biology Inorganic chemistry Active site Ligands Biochemistry Fluorescence Inorganic Chemistry chemistry.chemical_compound Crystallography chemistry Absorption edge Stability constants of complexes biology.protein Benzimidazoles Azide Absorption (chemistry) Cyclic voltammetry Copper |
| Zdroj: | Journal of Inorganic Biochemistry. 43:723-730 |
| ISSN: | 0162-0134 |
| DOI: | 10.1016/0162-0134(91)80043-h |
| Popis: | Dicopper complexes of the following benzimidazole-containing ligands have been studied as possible models for the active site of hemocyanin: EDTB (N,N,N′,N′-tetrakis-(2-benzimidazolylmethyl)-1,2-ethanediamine), EGTB (1,1,10,10-tetrakis-(2-benzimidazolylmethyl)-1,10-diaza-4,7-dioxadecane), and MEGTB (1,1,10,10-tetrakis-(1-methylbenzimidazol-2-ylmethyl)-1,10-diaza-4,7-dioxadecane). The initial oxygenation product of Cu 2 (EDTB)(ClO 4 ) 2 in Me 2 SO gives optical absorption maxima at 315 nm (ϵ = 3750 M −1 cm −1 ) and 690 nm (ϵ = 100 M −1 cm −1 ). The fluorescence emission intensities of Cu 2 (EDTB)(ClO 4 ) 2 at 400 and 700 nm (excitation at 350 nm) decreases rapidly on exposure to air. This suggests oxidation of Cu 2 (I) to Cu2(II). The x-ray absorption edge spectra suggest that both coppers in the oxygenation product, analyzed as Cu 2 (EDTB)(ClO 4 ) 2 (O) · 3H 2 O, are Cu(II). From spectrophotometric titration of Cu 2 (MEGTB)Cl 4 with azide, formation constant of the Cu 2 (MEGTB)N 3 Cl 3 , complex has been obtained. Data from cyclic voltammetry experiments suggest that in the presence of azide, Cu(II)(N 3 )Cu(II) species is present. |
| Databáze: | OpenAIRE |
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