A polyhedral oligomeric silsesquioxane (POSS)-bridged oxo-molybdenum Schiff base complex with enhanced heterogeneous catalytic activity in epoxidation
作者:Yan Leng、Jian Liu、Chenjun Zhang、Pingping Jiang
DOI:10.1039/c3cy01014g
日期:——
We have generated a new heterogeneous catalyst by bridging an oxo-molybdenum Schiff base on a polyhedral oligomeric silsesquioxane (POSS) via covalent attachment. The resulting POSS-bridged oxo-molybdenum Schiff base complex catalyst was fully characterized by 1H NMR, XRD, FT-IR, SEM, TGA, and contact angle analysis, and its catalytic potential was studied for the epoxidation of alkenes using aqueous
我们通过共价连接将多面体低聚倍半硅氧烷(POSS)上的氧钼席夫碱桥接,从而产生了一种新的非均相催化剂。通过1 H NMR,XRD,FT-IR,SEM,TGA和接触角分析对得到的POSS桥联的氧钼席夫碱络合物催化剂进行了充分表征,并研究了其催化潜力用于叔丁基醚水溶液的环氧化丁基过氧化氢(TBHP)作为氧化剂。发现该催化剂比相应的均相类似物高效且显示出更高的催化反应性,并具有容易回收和再循环非均相催化剂的额外益处。POSS桥联的氧钼希夫碱复合物成功地重复使用了四次,而活性没有明显损失。揭示了独特的三维网络催化剂结构和催化剂中POSS单元的疏水性,是造成催化剂在环氧化反应中优异性能的原因。