以1,4-双(三乙氧基硅基)苯和苯基膦钯有机金属硅烷为混合硅源,在表面活性剂导向组装下共缩聚制得Pd(Ⅱ)-PMO—KIT-6非均相催化剂,并利用NMR、XPS、XRD、TEM和氮气吸附等手段对催化剂进行了表征.考察了该催化剂在水介质Sonogashira反应中的催化性能,结果表明:所制备的Pd(Ⅱ)一PMO—KIT-6具有优异的催化活性和选择性,这主要归因于催化剂的高比表面积、双连续介孔结构有利于提高Pd(Ⅱ)活性位分散度,减少传质阻力;同时苯基桥联PMO构建形成的微环境增强表面疏水性,有利于反应底物的吸附和扩散.此外,催化剂还可以重复使用多次后活性没有明显降低.
A heterogenous Pd( Ⅱ ) organometal catalyst with bicontinuous cubic Ia3d mesostructure was synthesized by surfactant-directed co-condensation of Pd [ PPh2 ( CH2 )2Si ( OCH2CH3 )3 ] 2C12 and (CH3CH20) 3SiPhSi ( OCH2CH3 ) 3- In water-medium Sonogashira reaction, the as-prepared Pd ( Ⅱ )-PMO-KIT-6 exhibited higher catalytic activity than reference catalyst Pd ( Ⅱ )-KIT-6 and could be used repetitively for more than 4 times, which could reduce the cost and even diminish the environmental pollution from heavy metallic ions, showing a good potential in industrial applications.