Homochiral metal‐organic frameworks based on amino acid ligands for HPLC separation of enantiomers

Abstract

Natural amino acids are well known to form coordination polymers with transition metal ions. In this study, six homochiral metal-organic frameworks constructed from Zn or Co ions and various enantiopure amino acid (L-tyrosine, L-histidine, L-tryptophan and L-glutamic acid), namely [Zn(L-tyr)] (L-tyrZn), [Zn (btc) (Hbtc)(L-His) (H O) ]·1.5H O, {[Zn (L-trp) (bpe) (H O) ]·2H O·2NO } , [Co (L-Trp)(INT) (H O) (ClO )], [Co (sdba)((L-Trp) ] and [Co(L-Glu)(H O)·H O] , were synthesized according to the methods previously reported in the literature. The six homochiral MOFs were explored as the chiral stationary phases for high-performance liquid chromatographic separation of enantiomers using hexane/isopropanol or hexane/dichloromethane as mobile phase. Various types of enantiomers such as alcohols, amines, ketones, ethers, organic acids, etc. can be resolved on these homochiral MOF columns. The results revealed that the enantioseletivities of homochiral MOFs based on amino acids as chiral bridging ligands used as stationary phases are practical in HPLC.

Recent Bio-Advances in Metal-Organic Frameworks

“…These biologically essential compounds are used in the body for the synthesis of proteins or as a source of energy via oxidation to urea and CO 2 . Amino acids (except glycine) possess inherent chirality, which has been utilised to create homochiral MOFs for applications, such as separation of chiral structures [96]. 1D and 2D CPs can form due to the single carboxylate coordinating group which can be remedied through the use of ancillary ligands and mixed systems [21].…”

Amino Acid Functionalized Crystalline Porous Polymers

“…以手性固定相(CSP)法为代表的色谱拆分技术, 具 有分离时间短、手性选择性高等优点; 将氨基酸功能化 的手性 MOFs 用作高效液相色谱、气相色谱的固定相可 以实现手性分离. 袁黎明课题组 [43] 膜手性拆分技术以其能耗低、操作简单、可批量处 理、可连续操作等优点, 在手性拆分领域得到了广泛的 关注, 具有良好的应用前景 [4a] . 金万勤课题组 [46] 报道了 利用 L-天冬氨酸和联吡啶(bipy)作为配体原位合成三维 手性 MOF 材料-Ni 2 (L-Asp) 2 (bipy), 利用高能球磨法获 得了亚微米级大小的 MOF 晶种, 通过浸渍、涂覆将其 涂在陶瓷基底上, 然后通过二次生长制备薄膜.…”

Functional Metal Organic Framework/SiO2 Nanocomposites: From Versatile Synthesis to Advanced Applications

“…Given the large specific surface area, adjustable pore structure, and large number of active metal sites, MOFs have great potential in separation applications, especially in chromatographic column separation [84,85,86,87,88]. However, the irregular shape and wide size distribution of MOF particles lead to the difficulty in column packing, low column efficiency, or high column pressure.…”