Magnetic, spectroscopic, and structural studies of dicobalt hydroxamates and model hydrolases
| Autor: | W. K. Glass, Terence J. Kemp, S. M. Ostrovsky, William Errington, Wolfgang Haase, David Brown, Hassan Nimir, R. Werner |
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| Rok vydání: | 2001 |
| Předmět: |
Models
Molecular Magnetic Resonance Spectroscopy Urease Chemical Phenomena Hydrolases Molecular Conformation chemistry.chemical_element Crystallography X-Ray Hydroxamic Acids Medicinal chemistry Inorganic Chemistry chemistry.chemical_compound Hydrolase Organometallic Compounds Physical and Theoretical Chemistry biology Molecular Structure Chemistry Physical Temperature Cobalt Hydrogen Peroxide chemistry biology.protein Urea Spectrophotometry Ultraviolet Oxidation-Reduction Algorithms |
| Zdroj: | Inorganic chemistry. 40(23) |
| ISSN: | 0020-1669 |
| Popis: | The cobalt(II) urease model complex [Co(2)(mu-OAc)(3)(urea)(tmen)(2)][OTf] (2) prepared from the cobalt model hydrolase [Co(2)(mu-H(2)O)(mu-OAc)(2)(OAc)(2)(tmen)(2)] (1) undergoes facile reaction with acetohydroxamic acid (AHA) to give the monobridged hydroxamate complex [Co(2)(mu-OAc)(2)(mu-AA)(urea)(tmen)(2)][OTf]( )()(3) while 1 gives the dibridged hydroxamate complex [Co(2)(mu-OAc)(mu-AA)(2)(tmen)(2)][OTf] (4). The structures and Co-Co distances of the hydroxamate derivatives of 1 and 2 are very close to those of their nickel analogues and suggest that hydroxamic acids can also inhibit cobalt-based hydrolases as well as inhibiting urease. 1 also reacts with glutarodihydroxamic acid (gluH(2)A(2)) to eliminate hydroxylamine with formation of [Co(2)(mu-OAc)(2)[mu-O(N) (OC)(2)(CH(2))(3)](tmen)(2)][OTf] (5), the structure of which is very close to that of its nickel analogue. Both 1 and 3 show weak antiferromagnetic coupling. Oxidation of 1 with H(2)O(2) gives three dicobalt(III) hydroxy complexes (7-9), the first of which [Co(2)(mu-OAc)(2)(OAc)(2)(mu-OH)(tmen)(2)][OTf] (7) contains a bridging hydroxyl and the second [Co(2)(mu-OAc)(2)(OAc)(mu-OH)(OH)(tmen)(2)][OTf] (8) containing both a bridging and terminal hydroxyl, while the third [Co(2)(mu-OAc) (OAc)(2)(mu-OH)(2)(tmen)(2)][OTf] (9) contains two bridging OH groups with mixed-valence Co(II)/(Co(III) intermediates. |
| Databáze: | OpenAIRE |
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