基于苯磺酸和2,2′-联吡啶双配体的锰配合物的结构及其催化Mannich反应性能和机理

Dual ligands manganese complexes based on benzene sulfonic acid and 2,2′‑bipyridine:Structure and catalytic properties and mechanism in Mannich reaction

由溶剂热法合成了2个锰的超分子配合物[Mn_(2)(2,2'-bipy)_(4)(H_(2)O)Cl_(3)](L_1)·6H_(2)O (1)和[Mn(2,2'-bipy)_(2)(H_(2)O)Cl](L_(2))·3H_(2)O (2)(L_(1)^(-)=对甲基苯磺酸根,L_(2)^(-)=间硝基苯磺酸根,2,2'-bipy=2,2'-联吡啶),并用单晶X射线衍射、红外光谱、热重分析和氮气吸附-脱附测试对其进行了表征。以Mannich反应为探针,研究了2种配合物的催化性能,并通过对比2种配合物的扫描电镜和粉末X射线衍射表征结果,分析了配合物结构对其催化性能的影响。最后通过密度泛函理论预测了配合物的活性位点,利用X射线光电子能谱证明了活性位点的活化作用,进而阐述了配合物催化Mannich反应的机理。

Two supramolecular complexes of[Mn_(2)(2,2'⁃bipy)4(H_(2)O)Cl_(3)](L_(1))·6H_(2)O(1)and[Mn(2,2'⁃bipy)2(H_(2)O)Cl](L_(2))·3H_(2)O(2)(L_(1)^(-)=p⁃methylbenzenesulfonate anion,L_(2)^(-)=m⁃nitrobenzenesulfonate anion,2,2'⁃bipy=2,2'⁃bipyridine)were synthesized by solvothermal method.The complexes were characterized by single⁃crystal X⁃ray diffraction,infrared spectroscopy,thermogravimetric analysis,and nitrogen adsorption⁃desorption test.Using the Mannich reac⁃tion as a probe,the catalytic properties of the two complexes were studied,and the effects of the structure of the com⁃plexes on their catalytic properties were analyzed by comparing the results of scanning electron microscopy and pow⁃der X⁃ray diffraction.Finally,density functional theory was used to predict the active sites of the complexes,and X⁃ray photoelectron spectroscopy was used to prove the activation of the active sites.Then the mechanism of Mannich reaction catalyzed by the complexes was clarified.CCDC:2264043,1;2264042,2.