Zeolite and zeolite-like molecular sieves are being used in a large number of applications such as adsorption and catalysis. Achievement of the long-standing goal of creating a chiral, polycrystalline molecular sieve with bulk enantioenrichment would enable these materials to perform enantioselective functions. Here, we report the synthesis of enantiomerically enriched samples of a molecular sieve. Enantiopure organic structure directing agents are designed with the assistance of computational methods and used to synthesize enantioenriched, polycrystalline molecular sieve samples of either enantiomer. Computational results correctly predicted which enantiomer is obtained, and enantiomeric enrichment is proven by high-resolution transmission electron microscopy. The enantioenriched and racemic samples of the molecular sieves are tested as adsorbents and heterogeneous catalysts. The enantioenriched molecular sieves show enantioselectivity for the ring opening reaction of epoxides and enantioselective adsorption of 2-butanol (the R enantiomer of the molecular sieve shows opposite and approximately equal enantioselectivity compared with the S enantiomer of the molecular sieve, whereas the racemic sample of the molecular sieve shows no enantioselectivity).
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5441830 | PMC |
http://dx.doi.org/10.1073/pnas.1704638114 | DOI Listing |
Small
January 2025
Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China.
The properties and device applications of 2D semiconductors are highly sensitive to intrinsic structural defects due to their ultrathin nature. CuInSe (CIS) materials own excellent optoelectronic properties and ordered copper vacancies, making them widely applicable in photovoltaic and photodetection fields. However, the synthesis of 2D CIS nanoflakes remains challenging due to the nonlayered structure, multielement composition, and the competitive growth of various by-products, which further hinders the exploration of vacancy-related optoelectronic devices.
View Article and Find Full Text PDFFood Res Int
January 2025
Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, China. Electronic address:
A lipophilic piceid lipoate (PIL) was synthesized by enzymatic method to enhance the antioxidant activity of piceid and improve its state in oil system. The highest substrate conversion of 93.71 % was obtained in γ-valerolactone using Novozym 435 as a catalyst, with a piceid/lipoic acid ratio of 1:15 (mM/mM), an enzyme dosage of 40 mg/mL, and 4 Å molecular sieves at 400 mg/mL.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Department of Solid State Chemistry, Faculty of Chemical Technology, University of Chemistry and Technology, Technická 5, 16628 Prague, Czech Republic.
The most commonly used homogeneous catalyst for fatty acid esterification is a corrosive sulphuric acid. However, this requires costly investment in non-corrosive equipment, presents a safety risk, is time consuming, and increases effluent generation. In this study, inorganic 3D heteroborane cluster strong acids are employed for the first time as homogeneous catalysts.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Oak Ridge National Laboratory, Chemical Sciences Division, UNITED STATES OF AMERICA.
Precise sub-Ångstrom-level porosity engineering, which is appealing in gas separations, has been demonstrated in solid carbon, polymer, and framework materials but rarely achieved in the liquid phase. In this work, a gas molecular sieving effect in the liquid phase at sub-5 Ångstrom scale is created via sophisticated porosity tuning in calixarene-derived porous liquids (PLs). Type II PLs are constructed via supramolecular complexation between the sodium salts of calixarene derivatives and crown ether solvents.
View Article and Find Full Text PDFAnal Chem
January 2025
Interdisciplinary, Molecular Biology of Biological Function, Changbai Mountain Key Laboratory of Natural Medicine of Ministry of Education, Yanbian University, Yanji 133000, China.
Extracellular vesicles (EVs) play a crucial role in diagnosis and treatment, yet obtaining highly purified EVs from complex biological samples is often hindered by nanoscale contaminants. In this work, considering the charge-to-size characteristics of EVs, a circular multicavity electrophoresis (CME) with gradient pore size distribution was constructed in the gradient electric field to realize the isolation and preparation of EVs. By the gradient gel sieving effect, small cell debris, EVs, and proteins in biological samples were gradually separated.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!