Reactivities of Fe(IV) Complexes with Oxo, Hydroxo, and Alkylperoxo Ligands: An Experimental and Computational Study.
Saved in:
| Title: | Reactivities of Fe(IV) Complexes with Oxo, Hydroxo, and Alkylperoxo Ligands: An Experimental and Computational Study. |
|---|---|
| Authors: | Fiedler, Adam T.1, Quo Jr., Lawrence1 larryque@uma.edu |
| Source: | Inorganic Chemistry. 12/7/2009, Vol. 48 Issue 23, p11038-11047. 10p. |
| Subjects: | Iron compounds, Reactivity (Chemistry), Complex compounds, Hydroxides, Ligands (Chemistry), Dissociation (Chemistry), Electronic structure |
| Abstract: | In a previous paper [Jensen et al. J. Am. Chem. Soc. 2005, 127, 10512], we reported the synthesis of Ihe turquoise-colored intermediate [FeIV(β-BPMCN)(OO'Bu)(OH)]2+ (Tq; BPMCN = N,N'-bis(2-pyridylmethyl)-N,N'-dimethyl- trans-1,2-diaminocyclohexane). The structure of Tq is unprecedented, as it represents the only synthetic example to dale of a nonheme FeIV complex with both alkylperoxo and hydroxide ligands. Given the significance of similar high-valent Fe intermediates in the mechanisms of oxygenase enzymes, we have explored the reactivity of Tq at -70 °C, a temperature at which it is stable, and found that it is capable of activating weak X-H bonds (X = C, O) with bond dissociation energies ⩽∼80 kcal/mol. The FeIV-OH unit of Tq, and not the alkylperoxo moiety, performs the initial H-atom abstraction. However at -45 °C, Tq decays at a rate that is independent of substrate identity and concentration, forming a species capable of oxidizing substrates with stronger C-H bonds. Parallel reactivity studies were also conducted with the related oxoiron(IV) complexes [FeIV(β-BPMCN)(O)(X)]2+ (3-X; X = pyridine or nitrile), thereby permitting a direct comparison of the reactivity of FeIV centers with oxo and hydroxide ligands. We found that the H-atom abstracting ability of the FeIV=O species greatly exceeds that of the FeIV-OH species, generally by greater than 100-fold. Examination of the electronic structures of Tq and 3-X with density functional theory (OFT) provides a rationale for their differing reactivities. [ABSTRACT FROM AUTHOR] |
| Copyright of Inorganic Chemistry is the property of American Chemical Society and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
|---|---|
| Header | DbId: egs DbLabel: Engineering Source An: 47247991 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
| IllustrationInfo | |
| Items | – Name: Title Label: Title Group: Ti Data: Reactivities of Fe(IV) Complexes with Oxo, Hydroxo, and Alkylperoxo Ligands: An Experimental and Computational Study. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Fiedler%2C+Adam+T%2E%22">Fiedler, Adam T.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Quo+Jr%2E%2C+Lawrence%22">Quo Jr., Lawrence</searchLink><relatesTo>1</relatesTo><i> larryque@uma.edu</i> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Inorganic+Chemistry%22">Inorganic Chemistry</searchLink>. 12/7/2009, Vol. 48 Issue 23, p11038-11047. 10p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Iron+compounds%22">Iron compounds</searchLink><br /><searchLink fieldCode="DE" term="%22Reactivity+%28Chemistry%29%22">Reactivity (Chemistry)</searchLink><br /><searchLink fieldCode="DE" term="%22Complex+compounds%22">Complex compounds</searchLink><br /><searchLink fieldCode="DE" term="%22Hydroxides%22">Hydroxides</searchLink><br /><searchLink fieldCode="DE" term="%22Ligands+%28Chemistry%29%22">Ligands (Chemistry)</searchLink><br /><searchLink fieldCode="DE" term="%22Dissociation+%28Chemistry%29%22">Dissociation (Chemistry)</searchLink><br /><searchLink fieldCode="DE" term="%22Electronic+structure%22">Electronic structure</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: In a previous paper [Jensen et al. J. Am. Chem. Soc. 2005, 127, 10512], we reported the synthesis of Ihe turquoise-colored intermediate [FeIV(β-BPMCN)(OO'Bu)(OH)]2+ (Tq; BPMCN = N,N'-bis(2-pyridylmethyl)-N,N'-dimethyl- trans-1,2-diaminocyclohexane). The structure of Tq is unprecedented, as it represents the only synthetic example to dale of a nonheme FeIV complex with both alkylperoxo and hydroxide ligands. Given the significance of similar high-valent Fe intermediates in the mechanisms of oxygenase enzymes, we have explored the reactivity of Tq at -70 °C, a temperature at which it is stable, and found that it is capable of activating weak X-H bonds (X = C, O) with bond dissociation energies ⩽∼80 kcal/mol. The FeIV-OH unit of Tq, and not the alkylperoxo moiety, performs the initial H-atom abstraction. However at -45 °C, Tq decays at a rate that is independent of substrate identity and concentration, forming a species capable of oxidizing substrates with stronger C-H bonds. Parallel reactivity studies were also conducted with the related oxoiron(IV) complexes [FeIV(β-BPMCN)(O)(X)]2+ (3-X; X = pyridine or nitrile), thereby permitting a direct comparison of the reactivity of FeIV centers with oxo and hydroxide ligands. We found that the H-atom abstracting ability of the FeIV=O species greatly exceeds that of the FeIV-OH species, generally by greater than 100-fold. Examination of the electronic structures of Tq and 3-X with density functional theory (OFT) provides a rationale for their differing reactivities. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Inorganic Chemistry is the property of American Chemical Society and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
| PLink | https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=egs&AN=47247991 |
| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1021/ic901391y Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 10 StartPage: 11038 Subjects: – SubjectFull: Iron compounds Type: general – SubjectFull: Reactivity (Chemistry) Type: general – SubjectFull: Complex compounds Type: general – SubjectFull: Hydroxides Type: general – SubjectFull: Ligands (Chemistry) Type: general – SubjectFull: Dissociation (Chemistry) Type: general – SubjectFull: Electronic structure Type: general Titles: – TitleFull: Reactivities of Fe(IV) Complexes with Oxo, Hydroxo, and Alkylperoxo Ligands: An Experimental and Computational Study. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Fiedler, Adam T. – PersonEntity: Name: NameFull: Quo Jr., Lawrence IsPartOfRelationships: – BibEntity: Dates: – D: 07 M: 12 Text: 12/7/2009 Type: published Y: 2009 Identifiers: – Type: issn-print Value: 00201669 Numbering: – Type: volume Value: 48 – Type: issue Value: 23 Titles: – TitleFull: Inorganic Chemistry Type: main |
| ResultId | 1 |
