1. Differential Adsorption of <scp>l</scp> ‐ and <scp>d</scp> ‐Lysine on Achiral MFI Zeolites as Determined by Synchrotron X‐Ray Powder Diffraction and Thermogravimetric Analysis
- Author
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Tsz Woon Benedict Lo, Bolong Huang, Chiu Chung Tang, Sarah J. Day, Shik Chi Edman Tsang, Kwok Yin Wong, and Tianxiang Chen
- Subjects
Circular dichroism ,Thermogravimetric analysis ,Materials science ,010405 organic chemistry ,Rietveld refinement ,General Chemistry ,Microporous material ,General Medicine ,010402 general chemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Crystallography ,Adsorption ,X-ray crystallography ,Spectroscopy ,Powder diffraction - Abstract
Reported here is the first crystallographic observation of stereospecific bindings of l- and d-lysine (Lys) in achiral MFI zeolites. The MFI structure offers inherent geometric and internal confinement effects for the enantiomeric difference in l- and d-Lys adsorption. Notable differences have been observed by circular dichroism (CD) spectroscopy and thermogravimetric analysis (TGA). Distinct l- and d-Lys adsorption behaviours on the H-ZSM-5 framework have been revealed by the Rietveld refinement of high-resolution synchrotron X-ray powder diffraction (SXRD) data and the density-functional theory (DFT) calculations. Despite demonstrating the approach for l- and d-Lys over MFI zeolites at an atomistic resolution, the differential adsorption study sheds light on the rational engineering of molecular interaction(s) with achiral microporous materials for chiral separation purposes.
- Published
- 2019
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