Single-site homogeneous and heterogenized gold(III) hydrogenation catalysts:: Mechanistic implications
Single-site homogeneous and heterogenized gold(III) hydrogenation catalysts:: Mechanistic implications
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DOI：
10.1021/ja057998o
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发表时间：
2006-04-12
影响因子：
15
通讯作者：
Ujaque, G
中科院分区：
文献类型：
--
作者：
Comas-Vives, A;González-Arellano, C;Ujaque, G
Au（III）-Schiff碱配合物是活性氢化催化剂，其转换频率与Pd（II）的相应配合物相似，Pd（II）具有与Au（III）相同的d（8）电子结构。通过动力学实验和理论计算相结合的方法，对反应机理进行了详细的研究。预测并验证了溶剂的性质对H-2的异裂裂解（控制步骤）起着关键作用。考虑到这一点，并通过适当地选择固体载体的性质（极性和质子供给能力），可以通过将它们接枝到表面上来强烈地增加均相Au（III）和Pd（II）催化剂的活性。
Au(III)-Schiff base complexes are active hydrogenation catalysts, giving turnover frequencies similar to those of the corresponding complexes of Pd(II), which has the same d(8) electronic structure as Au(III). The mechanism of the reaction has been studied in detail by a combination of kinetic experiments and theoretical calculations. It is predicted and tested that the nature of the solvent plays a critical role for the heterolytic cleavage of H-2 (controlling step). Taking this into account, and by properly selecting the nature of solid supports (polarity and proton-donating ability), it was possible to strongly increase the activity of the homogeneous Au(III) and Pd(II) catalysts by grafting them onto the surface.