一种基于二氢吩嗪的三维共价有机框架的合成、结构与表征

Synthesis,Structure and Characterization of a Dihydrophenazine Based 3D Covalent Organic Framework

二氢吩嗪衍生物由于其独特的氧化还原活性而备受关注.本文先设计合成了一种含有二氢吩嗪基团的单体5,10-二(4-甲酰基苯基)-5,10-二氢吩嗪(M1),再采用溶剂热法,通过亚胺缩合反应制备了一种新型三维共价有机框架(3D COF,3D-PN-2).通过粉末X射线衍射(PXRD)、氮气吸附-脱附、傅里叶变换红外光谱(FTIR)和固体碳核磁共振波谱(^(13)C CP/MASNMR)等表征方法,并结合理论模拟对其结构信息进行了研究,得出3D-PN-2是具有十一重穿插金刚石(dia)拓扑结构的3D COF.采用扫描电子显微镜(SEM)和透射电子显微镜(TEM)对其形貌进行了表征.稳定性研究结果表明,3D-PN-2具有较好的热稳定性和化学稳定性.通过固体紫外-可见漫反射光谱研究了3D-PN-2的光吸收性能,结果表明,其在紫外和可见光区具有较宽的吸收范围(吸收边为630 nm),且具有较窄的能带间隙(2.11 eV).通过循环伏安法研究了其氧化还原性能,并计算得出其最高占有轨道能级(E_(HOMO))为−4.50 eV,最低空轨道能级(E_(LUMO))为−2.39 eV.

Dihydrophenazine derivatives have received considerable attention due to their unique redox activity.In this paper,a dihydrophenazine based monomer 5,10-di(4-formylphenyl)-5,10-dihydrophenazine(M1)was designed and synthesized,and 3D-PN-2 was then prepared with a Schiff-base reaction by the combination of M1 and tetrakis(4-aminophenyl)methane(TAM).3D-PN-2 was characterized by powder X-ray diffraction(PXRD),nitrogen adsorption-desorption experiment,FTIR,^(13)C CP/MAS NMR,SEM and TEM.After combined with theoretical simulation,3D-PN-2 was identified as a three-dimensional covalent organic framework(3D COF)with an 11-fold in⁃terpenetrated dia topology.Subsequent studies showed that 3D-PN-2 had good thermal and chemical stability.The optical absorption property of 3D-PN-2 was studied by UV-Vis diffuse reflectance spectrum.3D-PN-2 exhibits broad absorption in the region from UV to visible light(absorption edge:630 nm),and the band gap of 3D-PN-2 is 2.11 eV.The redox property was studied by cyclic voltammetry,and the highest occupied molecular orbital(E_(HOMO))and lowest unoccupied molecular orbital(E_(LUMO))were calculated to be−4.50 and−2.39 eV,respectively.These results suggest that 3D-PN-2 will be a promising COF candidate for photocatalysis applications.