担载的含氮、氧配体的Ni(Ⅱ)配合物对苯乙烯的催化环氧化研究

Epoxidation of Styrene Catalyzed by Immobilized Nickel(Ⅱ) Complexes with Ligands Containing Nitrogen and Oxygen

合成了３种含氮、氧配体的Ｎｉ（Ⅱ）配合物，并把它们担载于不同的载体上．在无有机溶剂及无相转移剂存在时，考察了在用ＮａＯＣｌ作为氧源时它们对苯乙烯环氧化的催化活性．用共沉淀法将微水溶性的Ｎｉ（ＰＡ）２（Ｈ２Ｏ）２固载于硅溶胶上；利用两种水溶性的新催化剂（Ｎｉ（Ｃ１２Ｈ１２Ｎ２Ｏ２）Ｃｌ２和Ｎｉ（Ｃ１６Ｈ１２Ｎ２Ｏ２）Ｃｌ２）离子型的特性，可以顺利的将它们固载于ＮａＹ型分子筛、Ｎａ基蒙脱土和离子交换树脂上，固载后催化剂的催化效果以固载于ＮａＹ型分子筛上为较佳．催化剂在固载后，苯乙烯的转化率和环氧选择性无明显降低．反应中加入一些氧化吡啶类添加剂，可以明显加快反应速度．其中对苯乙烯环氧化的转化率及选择性的影响，则以４－乙基氧化吡啶为最好．在适宜的反应条件下，固载后的催化剂（Ａ－Ｓ）可使苯乙烯环氧化转化率达到８３．０％，环氧化物选择性达６７．４％．

おhree nickel(Ⅱ) complexes with ligands containing nitrogen and oxygen atoms were synthesized and immobilized on different carriers. In the absence of organic solvent and phasetransfer agent, their catalytic activities for styrene epoxidation with NaOCl as oxygen source were studied. Slightly aqueous soluble catalyst (Ni(PA)2(H2O)2) could be coprecipitated on the silica sol. Two aqueous soluble new catalysts (Ni(C12H12N2O2)Cl2 and Ni(C16H12N2O2)Cl2) could be exchanged on NaYzeolite, Namontmorillonite and cation exchange resin using their cation interchange character. NaYzeolite was found to be the best carrier. The styrene conversion and epoxide selectivity of the Ni complexes did not change when immobilized. Pyridine Noxide derivates could accelerate the epoxidation reaction. Among these promoters, the 4ethyl pyridin Noxide increased the conversion and epoxide selectivity very significantly. Under suitable conditions, catalyst AS was found to have high styrene conversion (83.0%) and epoxide selectivity (67.4%). 