高稳定性的含氟多级孔共价有机框架材料

Highly Stable Fluorine Containing Hierarchical Porous Covalent Organic Framework

设计合成了一种新型含氟原子双孔共价有机框架(COF)——四(4-氨基苯)乙烯-2,3,5,6-四氟对二苯甲醛-COF(ETTA-TFA-COF),ETTA-TFA-COF是由1个D2h对称单体和1个C2对称单体连接而成的六角星形状结构,具有2. 93 nm六边形与1. 43 nm三角形的双孔结构.通过理论模拟、粉末X射线衍射(PXRD)、氮气吸附-解吸表征和傅里叶变换红外光谱(FTIR)等证实了ETTA-TFA-COF的结构.同时,通过与结构相似但不含氟原子的COF材料对比发现,ETTA-TFA-COF材料在碱性溶液中展现出优异的稳定性.

Covalent organic frameworks(COFs)are an emerging class of crystalline and porous polymers synthesized by condensation reactions of organic building blocks linked through strong covalent bonds.How-ever,constructing dual-pore COFs with applicative building blocks were faced with enormous challenges due to the complicated topological structures formed through the limited strategies.Herein we describe the design and synthesis of a new dual-pore COF with a hexagram-like structure,named ETTA-TFA-COF,synthesized by linking a D 2h symmetric monomer and a\%C\%2 symmetric monomer which leading the formation of dual-pore structure.The structure of the ETTA-TFA-COF was confirmed by theoretical simulation,powder X-ray diffraction(PXRD)investigation,nitrogen adsorption-desorption study,and FTIR spectra analysis.In the meantime,ETTA-TFA-COF material exhibit excellent stability in alkaline solution compared to COF materials of similar structure but without fluorine atoms.