高效金属有机骨架气相色谱固定相的理性设计  

Rational design of high performance metal organic framework stationary phase for gas chromatography

作　　者：杨涵 汤雯淇 曾楚 孟莎莎 徐铭 YANG Han;TANG Wenqi;ZENG Chu;MENG Shasha;XU Ming(School of Chemistry and Materials Science,Nanjing Normal University,Nanjing 210023,China)

机构地区：[1]南京师范大学化学与材料科学学院,江苏南京210023

出　　处：《色谱》2023年第10期853-865,共13页Chinese Journal of Chromatography

基　　金：国家自然科学基金(22204078);江苏省自然科学基金(BK20220370);江苏省教育厅项目(22KJB150009).

摘　　要：金属有机骨架材料(MOFs)由金属离子或金属簇与有机配体组装而成,其中多变的金属中心和有机配体使其具有高度可调性,这为调控高效气相色谱分离性能奠定了良好的结构基础。热力学作用力是描述分析物与固定相相互作用的基本指标,保留因子、麦氏常数、焓变与熵变等热力学值可以反映热力学作用力的相对大小。在微观层面上,可以通过设计MOFs孔隙内的多元作用力以开展热力学性质的研究,如设计金属亲和性、π-π相互作用、极性、手性位点等,这些热力学作用力可为分离具有微小差异的分析物提供有利环境。在动力学方面,MOFs的孔径大小与形状、颗粒尺寸、堆积模式对分析物的动力学扩散速率有着重要的影响,从改善分析物的动力学扩散角度出发,通过选择合适的孔径尺寸与形状、降低MOFs的颗粒尺寸、调控MOFs的堆积模式等手段,均可以提高气相色谱固定相的分离性能。根据色谱动力学统一方程和范蒂姆特方程计算扩散系数、理论塔板高度等动力学值,可有效评价色谱峰峰形和色谱柱柱效。在分离过程中,分析物的热力学作用力和动力学效应是协同作用的,且缺一不可。因此,本文从热力学与动力学两个角度提出了构建高效MOFs气相色谱固定相的设计思路,希望能为相关领域的研究提供一定帮助。Metal organic frameworks(MOFs)are assembled from metal ions or clusters and organic ligands.The high tunability of these components offers a solid structural foundation for achieving efficient gas chromatography(GC)separation.This review demonstrates that the design of high performance MOFs with suitable stationarity should consider both the thermodynamic interactions provided by these MOFs and the kinetic diffusion of analytes.Thermodynamic parameters are basic indicators for describing the interactions between various analytes and the stationary phase.Thermodynamic parameters such as retention factors,McReynolds constants,enthalpy changes,and entropy changes can reflect the relative intensity of thermodynamic interactions.For example,a larger enthalpy change indicates a stronger thermodynamic interaction between the analytes and stationary phase,whereas a smaller enthalpy change indicates a weaker interaction.In addition,the degree of entropy change reflects the relative degrees of freedom of analytes in the stationary phase.A larger entropy change indicates that the analytes have fewer degrees of freedom in the stationary phase.The higher the degree of restriction,the closer the adsorption of the analytes and,thus,the longer the retention time.Thermodynamic interactions,such as metal affinity,π-πinteractions,polarity,and chiral sites,can be rationally introduced into MOF structures by pre-or post-modifications depending on the target analytes.These tailored thermodynamic interactions create a favorable environment with subtle differences for efficient analyte separation.For example,MOF stationarity may require large conjugation centers to provide specificπ-πinteractions to separate benzenes.Chiral groups may be required in the MOF structure to provide sufficient interactions to separate chiral isomers.The kinetic diffusion rate of the analytes is another critical factor that affects the separation performance of MOFs.The diffusion coefficients of analytes in the stationary phase(D s)can be used to evaluate

关 键 词：金属有机骨架材料 气相色谱 固定相 热力学相互作用 动力学扩散 综述 

分 类 号：O658[理学—分析化学]