摘要
通过共聚法合成了嵌入式仲胺官能化的MCM-41,利用接枝法制备出介孔分子筛MCM-41负载的手性Salen Mn(Ⅲ)催化剂.采用FT-IR、DRUV-Vis、XRD、N2吸附、ICP等手段对其进行了表征.以其为催化剂,次氯酸钠、间氯过氧苯甲酸为氧化剂,分别用于苯乙烯、1,2-二氢化萘、顺--甲基苯乙烯以及-甲基苯乙烯等非官能团化烯烃的不对称环氧化反应.当以间氯过氧苯甲酸为氧化剂时,催化剂显示较高的转化率、环氧化物选择性和对映体过量值,但与相应的均相催化剂比,负载后催化剂活性和对应选择性都有所降低.同时对催化剂的循环使用性能进行了考察,发现络合物在催化反应过程中分解是催化剂失活的主要原因.
An embedded secondary amino group modified MCM-41 was synthesized by copolymerization method. Then the material was used as a support to immobilize a chiral Salen Mn （III） complex. The immobilized complex was characterized by FT-IR, DR UV-Vis, XRD, N2 adsorption-desorption and ICP methods, respectively. The material was used as a catalyst for the asymmetric epoxidation of styrene, 1,2-dihydronaphthalene, cis-methylstyrene,and -methylstyrene with NaClO and m-chloroperoxybenzoic acid （m-CPBA） as oxidants, respectively. The catalyst showed higher conversion of substrate, selectivity of epoxide and enantioselectivity with m-CPBA as oxidant. However, both the activity and en-antioselectivity of the complex decreased obviously after immobilization compared with those of the homogeneous one. The reusability of the catalyst was also studied and it was found that the decomposition of the complex in the catalytic runs was the main reason which led to the deactivation of the catalyst.
出处
《河北工业大学学报》
CAS
北大核心
2010年第2期11-16,共6页
Journal of Hebei University of Technology
基金
国家自然科学基金(20776035)
