Energy-gaining formation and catalytic behavior of active structures in a SiO(2)-supported unsaturated Ru complex catalyst for alkene epoxidation by DFT calculations.
Energy-gaining formation and catalytic behavior of active structures in a SiO(2)-supported unsaturated Ru complex catalyst for alkene epoxidation by DFT calculations.
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DOI：
10.1039/b710714e
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发表时间：
2007-11
期刊：
影响因子：
--
通讯作者：
Rudy Coquet;Mizuki Tada;Y. Iwasawa
中科院分区：
文献类型：
--
作者：
Rudy Coquet;Mizuki Tada;Y. Iwasawa
采用杂化密度泛函理论（DFT）计算方法研究了SiO(2)负载的不饱和Ru络合物烯烃环氧化催化剂中活性结构的形成和催化行为。发现了催化剂激活的能量获取途径，允许形成活性的不饱和Ru配合物，并通过异丁醛和氧之间的放热反应途径进行显着的烯烃环氧化。在提出的Bartlett机制中，Ru促进过酸中间体的形成，并促进过酸中间体中的分子间氢转移，而烯烃分子并不直接配位到Ru位点上。结果表明，由于苯基的给电子作用，二苯乙烯环氧化反应比乙烯环氧化反应更容易实现。
The formation and catalytic behavior of active structures in a SiO(2)-supported unsaturated Ru complex catalyst for alkene epoxidation were studied by means of hybrid density functional theory (DFT) calculations. An energy-gaining route for the catalyst activation was found to allow the formation of active unsaturated Ru complexes and the remarkable alkene epoxidation via an exothermic reaction path between isobutyraldehyde and oxygen. In the proposed Bartlett mechanism, Ru promotes the formation of peracid intermediate and facilitates the intermolecular hydrogen transfer in the peracid intermediate, while alkene molecules do not directly coordinate to the Ru site. It was found that stilbene epoxidation is easier to achieve than ethene epoxidation thanks to the electron donating phenyl groups.