MIL-53系列金属有机骨架化合物的合成及在Strecker反应中的催化性能

通过改变金属中心和配体官能团，合成了4个MIL-53系列金属有机骨架化合物NH₂-MIL-53（Sc），NH₂-MIL-53（Al），MIL-53（Sc）和NO₂-MIL-53（Sc）；研究了它们在合成α-氨基腈的Strecker反应中的催化性能.结果表明，NH₂-MIL-53（Sc）对于Strecker反应具有优异的催化性能，并具有可重复使用性.通过对比NH₂-MIL-53（Sc）和NH₂-MIL-53（Al）的催化性能，分析了金属离子半径和金属中心不饱和配位点对Strecker反应的影响.通过对比NH₂-MIL-53（Sc）与MIL-53（Sc）的催化性能，证明了作为路易斯碱中心的氨基可通过与路易斯酸中心的协同作用，有效促进Strecker反应的进行.通过对比NO₂-MIL-53（Sc）与MIL-53（Sc）的催化性能，认为催化剂结构上的硝基对于Strecker反应的进行具有重要影响.最后，通过对比NH₂-MIL-53（Sc）、硝酸钪和2-氨基对苯二甲酸（ATA）配体对催化性能的影响，总结出催化剂在纳米尺度的孔道结构是提高Strecker反应选择性的关键因素.

Syntheses of MIL-53 MOFs Materials and Their Catalytic Properties in Strecker Reactions

Four metal organic frameworks(MOFs), NH₂-MIL-53(Sc), NH₂-MIL-53(Al), MIL-53(Sc) and NO₂-MIL-53(Sc), were synthesized via changing the metal center and functional group of ligand, hereafter, their catalytic performance in the formation of α-aminonitrile(donated Strecker reaction) was investigated. Noteworthy, it is shown that the reusable NH₂-MIL-53(Sc) shows very good catalytic performance for Strecker reaction. Hereafter, comparing the catalytic experiments between NH₂-MIL-53(Sc) and NH₂-MIL-53(Al), the influence of metal ion radius and unsaturated coordination metal sites on Strecker reaction were analyzed. Furthermore, in comparison with the catalytic effects between NH₂-MIL-53(Sc) and MIL-53(Sc), the results demonstrated that the amino group can be served as the Lewis base sites, which can promote Strecker reaction through Lewis acid and Lewis base bifunctional synergistic mechanism. In addition, comparing the catalytic performances between NO₂-MIL-53(Sc) and MIL-53(Sc), it is confirmed that the NO₂ group on the catalyst structure has an important influence on the Strecker reaction. Finally, in comparison with the catalytic effects among NH₂-MIL-53(Sc), scandium nitrate and 2-aminoterephthalic acid(ATA) ligand, it is concluded that the nanoscale pore structure of NH₂-MIL-53(Sc) is the key factor to improve the selectivity of product in Strecker reaction.