Laser Flash Photolysis Study of Jacobsen Catalyst and Related Manganese(III) Salen Complexes. Relevance to Catalysis
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- 作者：Marí ; a J. Sabater ; Mercedes Á ; lvaro ; Hermenegildo Garcí ; a ; Emilio Palomares ; and J. C. Scaiano
- 刊名：Journal of the American Chemical Society
- 出版年：2001
- 出版时间：July 25, 2001
- 年：2001
- 卷：123
- 期：29
- 页码：7074 - 7080
- 全文大小：93K
- 年卷期：v.123,no.29(July 25, 2001)
- ISSN：1520-5126
文摘
The laser flash photolysis and emission properties of a set of five-coordinate manganese(III) Schiff-base complexes have been examined. In contrast to the intramolecular electron transfer between Mn3+ and theequatorial salen ligand reported to occur in the absence of axial coordination, our laser flash photolysis studyhas shown that the reactivity of the respective excited states is appreciably influenced by the electron donorstrength of the apical ligand at the metal center. In fact, homolytic and heterolytic photocleavage of the metal-ligand apical bond can be the most important processes upon laser excitation, their relative contribution beinginfluenced by medium effects and the 
-charge donation of the axial ligand. On the other hand, the detectionof reactive intermediates such as the oxomanganese(V) salen complex (
max 530 nm) by laser flash photolysisopens the way to apply this fast detection technique to the study of reaction mechanisms in catalysis by metalliccomplexes. As a matter of fact, quenching of oxomanganese(V) salen by simple alkenes has been observed bylaser flash.
-charge donation of the axial ligand. On the other hand, the detectionof reactive intermediates such as the oxomanganese(V) salen complex (max 530 nm) by laser flash photolysisopens the way to apply this fast detection technique to the study of reaction mechanisms in catalysis by metalliccomplexes. As a matter of fact, quenching of oxomanganese(V) salen by simple alkenes has been observed bylaser flash.