| dc.contributor |
Massachusetts Institute of Technology. Department of Chemistry |
|
| dc.contributor |
Friedle, Simone |
|
| dc.contributor |
Kodanko, Jeremy J. |
|
| dc.contributor |
Morys, Anna J. |
|
| dc.contributor |
Lippard, Stephen J. |
|
| dc.creator |
Friedle, Simone |
|
| dc.creator |
Kodanko, Jeremy J. |
|
| dc.creator |
Morys, Anna J. |
|
| dc.creator |
Hayashi, Takahiro |
|
| dc.creator |
Lippard, Stephen J. |
|
| dc.creator |
Moenne-Loccoz, Pierre |
|
| dc.date |
2013-11-15T19:38:30Z |
|
| dc.date |
2013-11-15T19:38:30Z |
|
| dc.date |
2009-09 |
|
| dc.date |
2009-07 |
|
| dc.date.accessioned |
2023-03-01T18:11:20Z |
|
| dc.date.available |
2023-03-01T18:11:20Z |
|
| dc.identifier |
0002-7863 |
|
| dc.identifier |
1520-5126 |
|
| dc.identifier |
http://hdl.handle.net/1721.1/82142 |
|
| dc.identifier |
Friedle, Simone, Jeremy J. Kodanko, Anna J. Morys, Takahiro Hayashi, Pierre Moënne-Loccoz, and Stephen J. Lippard. “Modeling the Syn Disposition of Nitrogen Donors in Non-Heme Diiron Enzymes. Synthesis, Characterization, and Hydrogen Peroxide Reactivity of Diiron(III) Complexes with the Syn N-Donor Ligand H2BPG2DEV.” Journal of the American Chemical Society 131, no. 40 (October 14, 2009): 14508-14520. |
|
| dc.identifier |
https://orcid.org/0000-0002-2693-4982 |
|
| dc.identifier.uri |
http://localhost:8080/xmlui/handle/CUHPOERS/279085 |
|
| dc.description |
In order to model the syn disposition of histidine residues in carboxylate-bridged non-heme diiron enzymes, we prepared a new dinucleating ligand, H[subscript 2]BPG[subscript 2]DEV, that provides this geometric feature. The ligand incorporates biologically relevant carboxylate functionalities, which have not been explored as extensively as nitrogen-only analogues. Three novel oxo-bridged diiron(III) complexes, [Fe[subscript 2](μ-O)(H[subscript 2]O)2(BPG[subscript 2]DEV)](ClO[subscript 4])[subscript 2] (6), [Fe[subscript 2](μ-O)(μ-O[subscript 2]CAr[superscript iPrO])(BPG[subscript 2]DEV)](ClO[subscript 4]) (7), and [Fe[subscript 2](μ-O)(μ-CO[subscript 3])(BPG[subscript 2]DEV)] (8), were prepared. Single-crystal X-ray structural characterization confirms that two pyridyl groups are bound syn with respect to the Fe−Fe vector in these compounds. The carbonato-bridged complex 8 forms quantitatively from 6 in a rapid reaction with gaseous CO[subscript 2] in organic solvents. A common maroon-colored intermediate (λ[subscript max] = 490 nm; ε = 1500 M[superscript −1] cm[superscript −1]) forms in reactions of 6, 7, or 8 with H[subscript 2]O[subscript 2] and NEt[subscript 3] in CH[subscript 3]CN/H[subscript 2]O solutions. Mass spectrometric analyses of this species, formed using [superscript 18]O-labeled H[subscript 2]O[subscript 2], indicate the presence of a peroxide ligand bound to the oxo-bridged diiron(III) center. The Mössbauer spectrum at 90 K of the EPR-silent intermediate exhibits a quadrupole doublet with δ = 0.58 mm/s and ΔE[subscript Q] = 0.58 mm/s. The isomer shift is typical for a peroxodiiron(III) species, but the quadrupole splitting parameter is unusually small compared to those of related complexes. These Mössbauer parameters are comparable to those observed for a peroxo intermediate formed in the reaction of reduced toluene/o-xylene monooxygenase hydroxylase with dioxygen. Resonance Raman studies reveal an unusually low-energy O−O stretching mode in the peroxo intermediate that is consistent with a short diiron distance. Although peroxodiiron(III) intermediates generated from 6, 7, and 8 are poor O-atom-transfer catalysts, they display highly efficient catalase activity, with turnover numbers up to 10 000. In contrast to hydrogen peroxide reactions of diiron(III) complexes that lack a dinucleating ligand, the intermediates generated here could be re-formed in significant quantities after a second addition of H[subscript 2]O[subscript 2], as observed spectroscopically and by mass spectrometry. |
|
| dc.description |
National Institute of General Medical Sciences (U.S.) (Grant GM032134) |
|
| dc.format |
application/pdf |
|
| dc.language |
en_US |
|
| dc.publisher |
American Chemical Society (ACS) |
|
| dc.relation |
http://dx.doi.org/10.1021/ja906137y |
|
| dc.relation |
Journal of the American Chemical Society |
|
| dc.rights |
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. |
|
| dc.source |
PMC |
|
| dc.title |
Modeling the Syn Disposition of Nitrogen Donors in Non-Heme Diiron Enzymes. Synthesis, Characterization, and Hydrogen Peroxide Reactivity of Diiron(III) Complexes with the Syn N-Donor Ligand H[subscript 2]BPG[subscript 2]DEV |
|
| dc.type |
Article |
|
| dc.type |
http://purl.org/eprint/type/JournalArticle |
|