Abstract
Chiral metal–organic frameworks (MOFs) have gained rising attention as ordered nanoporous materials for enantiomer separations, chiral catalysis, and sensing. Among those, chiral MOFs are generally obtained through complex synthetic routes by using a limited choice of reactive chiral organic precursors as the primary linkers or auxiliary ligands. Here, we report a template-controlled synthesis of chiral MOFs from achiral precursors grown on chiral nematic cellulose-derived nanostructured bio-templates. We demonstrate that chiral MOFs, specifically, zeolitic imidazolate framework (ZIF), unc-[Zn(2-MeIm)2, 2-MeIm=2-methylimidazole], can be grown from regular precursors within nanoporous organized chiral nematic nanocelluloses via directed assembly on twisted bundles of cellulose nanocrystals. The template-grown chiral ZIF possesses tetragonal crystal structure with chiral space group of P41, which is different from traditional cubic crystal structure of I-43 m for freely grown conventional ZIF-8. The uniaxially compressed dimensions of the unit cell of templated ZIF and crystalline dimensions are signatures of this structure. We observe that the templated chiral ZIF can facilitate the enantiotropic sensing. It shows enantioselective recognition and chiral sensing abilities with a low limit of detection of 39 μM and the corresponding limit of chiral detection of 300 μM for representative chiral amino acid, D- and L- alanine.
Original language | English |
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Article number | e202305646 |
Journal | Angewandte Chemie - International Edition |
Volume | 62 |
Issue number | 30 |
DOIs | |
State | Published - Jul 24 2023 |
Funding
We would like to thank Dr. J. Leisen for performing 13C CP/MAS NMR and Dr. A. Balzer and Dr. N. Stingelin for help with TGA. This work is supported by National Science Foundation (NSF) grant NSF-DMR 2303580, Air Force Office for Scientific Research grant FA9550-20-1-0305, and a grant from the South Korea National Research Foundation (NRF) (MSIT:2021R1A6A3A14039290). A portion of this research used resources at the Spallation Neutron Source, a Department of Energy (DOE) Office of Science User Facility operated by the Oak Ridge National Laboratory. We would like to thank Dr. J. Leisen for performing C CP/MAS NMR and Dr. A. Balzer and Dr. N. Stingelin for help with TGA. This work is supported by National Science Foundation (NSF) grant NSF‐DMR 2303580, Air Force Office for Scientific Research grant FA9550‐20‐1‐0305, and a grant from the South Korea National Research Foundation (NRF) (MSIT:2021R1A6A3A14039290). A portion of this research used resources at the Spallation Neutron Source, a Department of Energy (DOE) Office of Science User Facility operated by the Oak Ridge National Laboratory. 13
Keywords
- Chiral bio-templates
- chiral metal–organic frameworks
- enantioselective chemoresistive sensors