镁-三苯胺基金属有机框架的制备及其光/Lewis酸协同催化  

Preparation of magnesium-triphenylamine based metal organic framework and its synergistic Lewis acid and photoredox catalysis

作　　者：史雨生 宋靖修 张铁欣 段春迎[1] SHI Yusheng;SONG Jingxiu;ZHANG Tiexin;DUAN Chunying(State Key Laboratory of Fine Chemicals,Dalian University of Technology,Dalian 116024,Liaoning,China)

机构地区：[1]大连理工大学精细化工国家重点实验室,辽宁大连116024

出　　处：《精细化工》2021年第8期1635-1643,共9页Fine Chemicals

基　　金：国家自然科学基金(21971031,21890381,U1608224)。

摘　　要：利用水热法将具有Lewis酸性的Mg^(2+)和光敏性的三苯胺三羧酸(H3TCA)自组装构筑了金属有机框架Mg-TCA,并通过SC-XRD表征了其晶体结构。UV-Vis、FL、CV等测试表明,Mg-TCA在可见光区(>400 nm)具有良好的吸收,其激发态氧化还原电位为-1.95V(vs.SCE)。以苯乙烯类化合物(0.2mmol)为底物、N-羟基邻苯二甲酰亚胺(NHPI)活性酯(0.3 mmol)为自由基前体、Mg-TCA(0.01 mmol)为催化剂、DMSO(2 mL)为溶剂和氧化剂,氮气保护,在405 nm LED下照射24 h,反应以30%~82%的产率生成相应的α-烷基苯乙酮。催化剂Mg-TCA循环使用2次后仍保持活性和晶态结构。机理研究表明,在反应过程中发生了光/Lewis酸协同催化,Mg-TCA中具有Lewis酸性的镁节点对NHPI活性酯的吸附作用拉近了其与光催化中心三苯胺的距离,从而提升了催化反应的效率。Metal organic framework Mg-TCA was constructed by hydrothermal self-assembly between Lewis acidic Mg^(2+) and photosensitive tricarboxytriphenyl amine(H3 TCA).SC-XRD was used to determine the crystal structure of Mg-TCA.CV,UV-Vis and FL measurements indicated that Mg-TCA had a good absorption ability in visible light region and its photoexcited redox potential was -1.95 V(vs.SCE).Mg-TCA could effectively allow access to a wide range of α-alkyl-acetophenones(30%~82%)under the synergistic Lewis acid and photoredox catalysis,and the reaction conditions was obtained as follows:styrene compounds(0.2 mmol),N-hydroxyphthalimide(NHPI)ester(0.3 mmol),Mg-TCA(0.01 mmol),DMSO(2 mL),irradiation under 405 nm LED for 24 h at N_(2) atmosphere.The catalyst could be reused for two times without deactivation,and its structure remained intact before and after use.Mechanism studies revealed that a synergistic Lewis acid and photoredox catalysis process was carried out within this transformation,the Lewis acidic nodes of Mg-TCA binded and absorbed NHPI ester,putting the NHPI ester approximate to the photoredox catalytic center within Mg-TCA,thus improving the catalytic efficiency.

关 键 词：金属有机框架 镁 三苯胺 光摧化 LEWIS酸 协同催化 

分 类 号：TQ244.2[化学工程—有机化工] TQ426