Covalent Heterogenization of a Discrete Mn(ll) Bis-Phen Complex by a Metal-Template/Metal-Exchange Method: An Epoxidation Catalyst with Enhanced Reactivity.
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| Title: | Covalent Heterogenization of a Discrete Mn(ll) Bis-Phen Complex by a Metal-Template/Metal-Exchange Method: An Epoxidation Catalyst with Enhanced Reactivity. |
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| Authors: | Terry, Tracy J.1, Stack, T. Daniel P.1 stack@stanford.edu |
| Source: | Journal of the American Chemical Society. 4/9/2008, Vol. 130 Issue 14, p4945-4953. 9p. 6 Charts, 2 Graphs. |
| Subjects: | Epoxy compounds, Catalysts, Catalysis, Manganese, Ligands (Chemistry), Alkenes |
| Abstract: | Considerable attention has been devoted to the immobilization of discrete epoxidation catalysts onto solid supports due to the possible benefits of site isolation such as increased catalyst stability, catalyst recycling, and product separation. A synthetic metal-template/metal-exchange method to imprint a covalently attached bis-1,10-phenanthroline coordination environment onto high-surface area, mesoporous SBA-15 silica is reported herein along with the epoxidation reactivity once reloaded with manganese. Comparisons of this imprinted material with material synthesized by random grafting of the ligand show that the template method creates more reproducible, solution-like bis-1,10-phenanthroline coordination at a variety of ligand loadings. Olefin epoxidation with peracetic acid shows the imprinted manganese catalysts have improved product selectivity for epoxides, greater substrate scope, more efficient use of oxidant, and higher reactivity than their homogeneous or grafted analogues independent of ligand loading. The randomly grafted manganese catalysts, however, show reactivity that varies with ligand loading while the homogeneous analogue degrades trisubstituted olefins and produces trans-epoxide products from cis-olefins. Efficient recycling behavior of the templated catalysts is also possible. [ABSTRACT FROM AUTHOR] |
| Copyright of Journal of the American Chemical Society 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 |
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| Header | DbId: egs DbLabel: Engineering Source An: 31883708 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Covalent Heterogenization of a Discrete Mn(ll) Bis-Phen Complex by a Metal-Template/Metal-Exchange Method: An Epoxidation Catalyst with Enhanced Reactivity. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Terry%2C+Tracy+J%2E%22">Terry, Tracy J.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Stack%2C+T%2E+Daniel+P%2E%22">Stack, T. Daniel P.</searchLink><relatesTo>1</relatesTo><i> stack@stanford.edu</i> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Journal+of+the+American+Chemical+Society%22">Journal of the American Chemical Society</searchLink>. 4/9/2008, Vol. 130 Issue 14, p4945-4953. 9p. 6 Charts, 2 Graphs. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Epoxy+compounds%22">Epoxy compounds</searchLink><br /><searchLink fieldCode="DE" term="%22Catalysts%22">Catalysts</searchLink><br /><searchLink fieldCode="DE" term="%22Catalysis%22">Catalysis</searchLink><br /><searchLink fieldCode="DE" term="%22Manganese%22">Manganese</searchLink><br /><searchLink fieldCode="DE" term="%22Ligands+%28Chemistry%29%22">Ligands (Chemistry)</searchLink><br /><searchLink fieldCode="DE" term="%22Alkenes%22">Alkenes</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Considerable attention has been devoted to the immobilization of discrete epoxidation catalysts onto solid supports due to the possible benefits of site isolation such as increased catalyst stability, catalyst recycling, and product separation. A synthetic metal-template/metal-exchange method to imprint a covalently attached bis-1,10-phenanthroline coordination environment onto high-surface area, mesoporous SBA-15 silica is reported herein along with the epoxidation reactivity once reloaded with manganese. Comparisons of this imprinted material with material synthesized by random grafting of the ligand show that the template method creates more reproducible, solution-like bis-1,10-phenanthroline coordination at a variety of ligand loadings. Olefin epoxidation with peracetic acid shows the imprinted manganese catalysts have improved product selectivity for epoxides, greater substrate scope, more efficient use of oxidant, and higher reactivity than their homogeneous or grafted analogues independent of ligand loading. The randomly grafted manganese catalysts, however, show reactivity that varies with ligand loading while the homogeneous analogue degrades trisubstituted olefins and produces trans-epoxide products from cis-olefins. Efficient recycling behavior of the templated catalysts is also possible. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Journal of the American Chemical Society 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.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1021/ja0742030 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 9 StartPage: 4945 Subjects: – SubjectFull: Epoxy compounds Type: general – SubjectFull: Catalysts Type: general – SubjectFull: Catalysis Type: general – SubjectFull: Manganese Type: general – SubjectFull: Ligands (Chemistry) Type: general – SubjectFull: Alkenes Type: general Titles: – TitleFull: Covalent Heterogenization of a Discrete Mn(ll) Bis-Phen Complex by a Metal-Template/Metal-Exchange Method: An Epoxidation Catalyst with Enhanced Reactivity. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Terry, Tracy J. – PersonEntity: Name: NameFull: Stack, T. Daniel P. IsPartOfRelationships: – BibEntity: Dates: – D: 09 M: 04 Text: 4/9/2008 Type: published Y: 2008 Identifiers: – Type: issn-print Value: 00027863 Numbering: – Type: volume Value: 130 – Type: issue Value: 14 Titles: – TitleFull: Journal of the American Chemical Society Type: main |
| ResultId | 1 |
