Preparation Of Two Chiral MOFs And Study On Their Chromatographic Performance

Metal organic frameworks?MOFs?,also known as metal-organic coordination polymers,are one of the most representative materials in the third generation of porous materials.As a new type of functional material,MOFs have high specific surface area,abundant topological structure and easily modified pore surface.Over the past decade,MOFs have become one of the fastest growing areas in chemical research.Although the research of MOFs has developed rapidly and the number has increased sharply,the development of chiral MOFs has been slow.Chiral MOFs not only have the characteristics of general MOFs,but also can use chiral pores or chiral functional groups to selectively recognize chiral compounds.In the field of chiral separation,there have been some reports about the use of chiral MOFs as the stationary phases of gas chromatography?GC?and high performance liquid chromatography?HPLC?.However,there have even fewer reports about its application as the adsorbent and stationary phase of capillary electrochromatography?CEC?.The main contents of this thesis are as follows:Chapter one,the concept and classification of metal-organic frameworks were stated.The synthesis and application of chiral metal-organic frameworks were also reviewed.Chapter two,a chiral MOF,Co-?D-Cam?_1/2?bdc?_1/2?TMDPy?,which was defined as Co-MOF,was fabricated?D-Cam=D-camphoric acid;bdc=1,4-benzenedicarboxylate;tmdpy=4,4'-trimethylenedipyridine?.It was characterized by scanning electron microscopy?SEM?,X-ray diffraction?XRD?and fourier transform infrared spectroscopy?FT-IR?.The chiral MOF was used as a solid phase adsorbent.The selective adsorption of the enantiomers of atenolol and clenbuterol hydrochloride on the chiral Co-MOF was investigated.The effects of the eluent type and the adsorption time were also investigated.Under the conditions of n-hexane:isopropanol of 8:2?v:v?,adsorption time of 15 min,the chiral MOF had a certain selective adsorption difference on the two enantiomers of atenolol and clenbuterol hydrochloride.Chapter three,using L-histidine,2-methylimidazole and Zn?NO₃?₂·6H₂O as raw materials,a chiral MOF,which was defined as L-his-ZIF-8,was synthesized and characterized by SEM,XRD and FT-IR.Assisted with a polymer coating method,the chiral MOF was fixed to the inner wall of the capillary to obtain an open tubular capillary column modified with L-his-ZIF-8.The enantioseparation of a chiral compound—benzoin was investigated on the open tubular capillary column in CEC.The effects of buffer types and concentrations,pH values,types and contents of organic modifiers were investigated.Partial chiral resolution of benzoin was achieved.Chapter four,our group had previously produced a series of dialkyltartrate–boric acid,L-sorbose–boric acid,D-?+?-xylose–boric acid complexes in the organic solvent.They were respectively used as the chiral selectors in NACE for the enantioseparation of some chiral drugs like amino alcohols and phenothiazines.Based on the previous work,a method for the determination of enantiomers of metoprolol tartrate in tablets by nonaqueous capillary electrophoresis?NACE?was established.D-Gluconic acid?boric acid complex was used as the chiral selector.The experiments were carried out under the optimized chiral NACE conditions.The method was validated by methodology for the determination of enantiomer content in metoprolol tartrate tablets.Chapter five,conclusions and outlook.