2006 Fiscal Year Final Research Report Summary
Development of Highly Selective Light-driven Alkane Oxidation System Catalyzed by Ruthenium Complex under Visible Light Irradiation
| Project/Area Number |
17550106
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Synthetic chemistry
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| Research Institution | TOKYO METROPOLITAN UNIVERSITY |
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Principal Investigator |
YAMAGUCHI Motoo TOKYO METROPOLITAN UNIVERSITY, DEPARTMENT OF APPLIED CHEMISTRY, ASSOCIATE PROFESSOR, 都市環境科学研究科, 准教授 (60174637)
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| Co-Investigator(Kenkyū-buntansha) |
MASUI Dai TOKYO METROPOLITAN UNIVERSITY, DEPARTMENT OF APPLIED CHEMISTRY, RESEARCH ASSOCIATE, 都市環境科学研究科, 研究員 (10315757)
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| Project Period (FY) |
2005 – 2006
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| Keywords | Ruthenium complexes / Alkane oxygenation / Visible light oxidation / Pyridine N-oxide |
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| Research Abstract |
We have succeeded to utilize the coordinatively unsaturated species generated by photochemical ligand dissociation in catalytic oxidation reaction. We found that the non-heme type ruthenium complex was active in catalytic alkane oxidation under visible light irradiation in the presence of pyridine N-oxide. The oxidation is highly selective for the oxidation of tertiary carbon to give corresponding alcohol. The rate-determining step is assumed to be the C-H bond scission. Since the reaction proceeds with complete retention of the configuration, the mechanism involving free radicals can be excluded and the rebound mechanism was suggested as the one for Methane Monooxidase.
The detailed studies on the photoreaction of the ruthenium complex revealed that the key intermediate of the photooxidation was the dichloro ruthenium complex produced by the irradiation at MLCT absorption band resulting in the five-coordinated intermediate after the ligand dissociation of a monodentate ligand followed by recoordination of the counter anion, a chloride ion. Photodissociation from the catalyst precursor giving rise to the coordinatively unsaturated species was turned out to be the key step of the reaction, which realized the novel catalytic alkane oxidation system under visible light irradiation, which was freely controllable by ON-OFF switching of irradiation. Furthermore, the intermediates having various halogen ions by using bis(acetonitrlie) complex were successfully obtained in situ, and their catalytic ability were examined. The important information on the mechanism and the character of the catalyst became available by comparing those activities.
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Research Products
(4 results)
