用环糊精的金属有机框架材料作为模板制备多孔有机笼  

Fabrication of Porous Covalent Organic Cages Using Cyclodextrin Metal-Organic Frameworks as Template

作　　者：李阳雪[1] 张巍[1] 刘智 谢志刚[1] 

机构地区：[1]中国科学院长春应用化学研究所高分子物理与化学国家重点实验室,长春130022 [2]吉林省食品检验所,长春130103

出　　处：《化学学报》2015年第6期641-645,共5页Acta Chimica Sinica

基　　金：国家自然科学基金(No.91227118)资助~~

摘　　要：迄今为止,还未有报道过由金属有机框架材料(MOFs)转化成共价有机笼(COF-Cages)的文章.通过交联环糊精MOF骨架中的羟基,并除去其中的钾离子,构建了由环糊精MOF转化形成的结晶性多孔有机笼.首先合成CD-MOF,再将CD-MOF中的羟基交联,得到Cross-linkedγ-环糊精MOF(CL-CD-MOF),最后除去钾离子得到Z-cage,并且应用热重分析(TGA)、红外光谱(IR)、固体核磁共振(CP/MAS/NMR)光谱等多种分析手段对其结构进行表征.结果表明,该方法得到的有机笼(Z-cage)具有特定的方钠石型晶体结构,并且比表面积达862 m2·g-1.作为对照实验,在水热条件下,将γ-CD和对苯二硼酸按照1∶4化学计量比合成的CL-polymer与Z-cage具有不同的晶体结构,并通过X-射线粉末衍射(PXRD)进行了证明,反映了MOF模板合成法在控制材料的晶体结构的优越性.这种从结晶性无机-有机杂化MOF到结晶性有机笼Z-cage的转变,提供了多孔晶体材料之间晶体到晶体转变的途径.Up to now, transformation from metal-organic frameworks(MOFs) to covalent-organic-framework cages(COF-Cages) has never been reported. In this report, we demonstrated an organic cage crystal by transformation from a cyclodextrin MOF, via boronate ester formation reaction of the hydroxy groups of γ-CD inside the MOF, followed by removing of the potassium ions. First, CD-MOF was prepared by reacting γ-CD with potassium hydroxide in aqueous solution, followed by vapor diffusion of methanol into the solution according to a previously reported method. The freshly prepared CD-MOF was first washed with ethanol three times to remove the unreacted reactants, and then added to an ethanol saturated solution of benzene-1,4-diboronic acid(BDBA) in a screw top vial, and kept it at 65 ℃ for three days. Finally, the covalent cross-linked CD-MOF(CL-CD-MOF) was obtained by forming boronic esters between the uncoordinated C(2) and C(3) hydroxy groups of contiguous γ-CD sides in the CD-MOF pores and two boronic acid groups of BDBA. Structure and physical properties of Z-Cages were fully characterized by thermogravimetric analysis(TGA), infrared spectroscopy(IR), powder X-ray diffraction(PXRD), solid-state 13 C and 11 B cross polarization/magic angle spining nuclear magnetic resonance(CP/MAS/NMR) spectroscopy and nitrogen adsorption. The obtained zeolite-type organic cage(Z-cage) displayed a targeted sodalite-type crystalline structure and permanent porosity with the surface area of 862 m2g-1. A control experiment, the cross-linked polymers(CL-polymer) formed by coupling of γ-CD and BDBA was done by solvothermal method. The CL-polymer was synthesized by the heating of a 4∶1 stoichiometric mixture of BDBA and γ-CD at 90 ℃ for three days in dimethylformamide(DMF). PXRD pattern shows the CL-polymer are crystalline, but totally different with Z-cage. This transformation from crystalline inorganic-organic hybrid framework of MOF to crystalline organic framework provides an opportunity for crystal-to-crystal in porous crystalline

关 键 词：环糊精 金属有机框架材料 有机笼 交联聚合物 模板合成法 

分 类 号：TB383.4[一般工业技术—材料科学与工程] O636.12[理学—高分子化学]