催化学报

催化学报 ›› 2010, Vol. 31 ›› Issue (11): 1388-1392.DOI: 10.3724/SP.J.1088.2010.00525

• 研究论文 • 上一篇    下一篇

有序介孔有机金属 Pd(II) 的制备及其催化水介质中的 Suzuki 反应

朱凤霞, 杨旭石, 杨迪迪, 李和兴   

  1. 上海师范大学化学系, 上海 200234
  • 收稿日期:2010-05-20 出版日期:2010-11-12 发布日期:2014-03-28

Preparation of Ordered Mesoporous Organometallic Pd(II) and Its Catalytic Performance for Suzuki Reactions in Water Medium

ZHU Fengxia, YANG Xushi, YANG Didi, LI Hexing*   

  1. Department of Chemistry, Shanghai Normal University, Shanghai 200234, China
  • Received:2010-05-20 Online:2010-11-12 Published:2014-03-28

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摘要： 以有机金属 Pd 硅烷和乙基桥联硅烷为混合硅源, 在表面活性剂作用下进行共缩聚反应, 制备了有序介孔有机金属 Pd(II) 催化剂 Pd(II)-PMO(Et). 采用傅里叶变换红外光谱、核磁共振谱、X 射线衍射、透射电子显微镜和 N2 吸附脱附等手段对催化剂进行了表征. 结果表明, 与后嫁接法相比, 共聚法制得的催化剂活性位分散均匀, 孔道不易堵塞, 同时乙基修饰的孔壁增强了催化剂表面疏水性, 有利于反应物在孔道内的扩散和吸附. 在水介质 Suzuki 反应中, Pd(II)-PMO(Et) 的催化活性与均相催化剂 Pd(PPh3)2Cl2 的相当, 且可重复使用.

关键词: 有序介孔有机金属钯 (II), 均相催化剂固载化, 水介质, 卤代烃, Suzuki 反应, 共缩聚

Abstract: Ordered mesoporous Pd(II) organometallic catalyst Pd(II)-PMO(Et) was synthesized by surfactant-directed co-polymerization of ethyl- and Pd(II) organometal-bridged silanes, and was characterized by Fourier transform infrared spectroscopy, NMR, X-ray powder diffraction, transmission electron microscopy, and nitrogen sorption techniques. Compared with the as-prepared Pd(II)-PMO(Et)-G by the grafting method, Pd(II)-PMO(Et) catalyst showed high dispersion of Pd(II) active sites and reduced diffusion limit. Moreover, this catalyst exhibited similar activity to the corresponding Pd(PPh3)2Cl2 homogeneous catalyst in water-medium Suzuki reactions. This can be attributed to the high dispersion of Pd(II) active sites, ordered mesoporous channels, and strong surface hydrophobicity resulted from ethyl fragments embedded in silica walls, the facilitating diffusion and adsorption of organic molecules onto the catalyst in aqueous solution. The Pd(II)-PMO(Et) could be used repeatedly and showed excellent durability, which can be attributed to the effective inhibition of Pd(II) leaching and the high hydrothermal stability of the mesoporous structure.

Key words: ordered mesoporous Pd(II) organometallic catalyst, immobilization of homogeneous catalyst, water medium, arylhalide, Suzuki reaction, co-polymerization