Synthesis, characterization and activity of imidazolate-bridged and Schiff-base dinuclear complexes as models of Cu,Zn-SOD. A comparative study.
J Inorg Biochem
; 163: 162-175, 2016 10.
Article
em En
| MEDLINE
| ID: mdl-27426051
Two imidazolate-bridged diCuII and CuIIZnII complexes, [CuZn(dien)2(µ-Im)](ClO4)3·MeOH (1) and [Cu2(dien)2(µ-Im)](ClO4)3 (2) (Im = imidazole, dien=diethylenetriamine), and two complexes formed with Schiff base ligands, [CuZn(salpn)Cl2] (3) and [Cu2(salbutO)ClO4] (4) (H2salpn=1,3-bis(salicylidenamino)propane, H3salbutO=1,4-bis(salicylidenamino)butan-2-ol) have been prepared and characterized. The reaction of [Cu(dien)(ImH)](ClO4)2 with [Zn(dien)(H2O)](ClO4)2 at pH≥11 yields complex 1; at lower pH, the Cu3Zn tetranuclear complex [{(dien)Cu(µ-Im)}3Zn(OH2)(ClO4)2](ClO4)3 (1a) forms as the main reaction product. X-ray diffraction of 1a reveals that the complex contains a metal centered windmill-shaped cation having three blades with a central Zn ion and three peripheral capping Cu(dien) moieties bound to the central Zn ion through three imidazolate bridges. The four complexes are able to disproportionate O2- in aqueous medium at pH7.8, with relative rates 4>1>2â«3. [Cu2(salbutO)]+ (4) is the most easily reducible of the four complexes and exhibits the highest activity among the SOD models reported so far; a fact related to the ligand flexibility to accommodate the copper ion in both CuI and CuII oxidation states and the lability of the fourth coordination position of copper facilitating stereochemical rearrangements.
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Texto completo:
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Superóxido Dismutase
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Superóxidos
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Cobre
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Imidazóis
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Modelos Químicos
Idioma:
En
Revista:
J Inorg Biochem
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Argentina
País de publicação:
Estados Unidos