以2-(二苯基膦)乙基三乙氧基硅烷和正硅酸乙酯为混合硅源,运用延时共缩聚法制备带有二苯基膦(PPh2-)修饰配体的KIT-6型介孔氧化硅材料,通过络合Ru(Ⅱ)获得固载化Ru(Ⅱ)有机金属催化剂(Ru-PPh2-KIT-6),该催化剂具有规整介孔结构.在水相烯丙醇异构化反应中显示高活性和高选择性,催化性能接近均相催化剂,活性相与载体结合牢固,能够重复使用5次以上.
A diphenylphosphine( PPh2 )-modified KIT-6 type mesoporous silica was synthesized by co-condensation method using tetraethoxysilane(TEOS) and 2-(diphenylphosphino) ethyltriethoxysilane (DPPTS) as the mixed silicon source, from which the immobilize Ru(Ⅱ) organometallic catalyst was obtained through strong coordination between the PPh2-group on the KIT-6 support and the Ru(Ⅱ). The as-prepared Ru-PPh2-KIT-6 catalyst exhibited ordered mesoporous structure. During the isomerization of homoallylic alcohol in an aqueous medium, the Ru-PPh2- KIT-6 catalyst exhibited high activity and selectivity, almost the same as the corresponding homogeneous catalyst. The catalyst could be used repetitively for more than 5 times owing to the strong interaction of the Ru(Ⅱ) active sites with the support which prevent them from leaching.