Hydrocarbon-pool chemistry is important in methanol to olefins (MTO) conversion on acidic zeolite catalysts. The hydrocarbon-pool (HP) species, such as methylbenzenes and cyclic carbocations, confined in zeolite channels during the reaction are essential in determining the reaction pathway. Herein, we experimentally demonstrate the formation of supramolecular reaction centers composed of organic hydrocarbon species and the inorganic zeolite framework in H-ZSM-5 zeolite by advanced (13)C-(27)Al double-resonance solid-state NMR spectroscopy. Methylbenzenes and cyclic carbocations located near Brønsted acid/base sites form the supramolecular reaction centers in the zeolite channel. The internuclear spatial interaction/proximity between the (13)C nuclei (associated with HP species) and the (27) Al nuclei (associated with Brønsted acid/base sites) determines the reactivity of the HP species. The closer the HP species are to the zeolite framework Al, the higher their reactivity in the MTO reaction.
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http://dx.doi.org/10.1002/anie.201510920 | DOI Listing |
J Am Chem Soc
January 2025
Key Laboratory of Bioorganic Phosphorous and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, China.
Zigzag aromatic hydrocarbon belts, ultrashort segments of zigzag carbon nanotubes, have been fascinating in the chemistry community for more than a half century because of their aesthetically appealing molecular nanostructures and tantalizing applications. Precise introduction of heteroatoms of distinct electronegativity and electronic configuration can create various heterocyclic aromatic nanobelts with novel physical and chemical properties. Here, we report the synthesis of unprecedented N-doped zigzag-type aromatic belts, belt[]pyrrole[]pyridines ( = 6-8), from multiple intramolecular C-C homocoupling reactions of readily available azacalix[](3,5-dibromopyridine)s.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
School of Chemistry and Chemical Engineering, Institute of Materials Sciences and Engineering, Institute of Clean Energy and Advanced Nanocatalysis (iClean), Anhui Province Key Laboratory of Coal Clean Conversion and High Valued Utilization, Anhui University of Technology, Maanshan 243002, China.
Herein, the reduction of the Cu oxidation state during the CO electro-reduction reaction (CORR) is effectively inhibited by depositing C supramolecular clusters onto the Cu(OH)F surface. By utilizing the unique electronic buffering capacity of C, a significant number of Cu/Cu sites are created, leading to a remarkable faradaic efficiency of C products up to 76.9% and exceptional stability.
View Article and Find Full Text PDFInorg Chem
January 2025
School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, Changchun 130022, People's Republic of China.
Int J Biol Macromol
December 2024
Department of Chemistry, Himachal Pradesh University, Shimla 171005, India.
The versatile properties of carbohydrate polymers make them a relevant, promising precursor to design innovative materials for use in biomedical applications. Recent research mainly focuses on the development of the polysaccharide based functional materials. Hydrogel derived materials are a source of great motivation for the development of drug delivery (DD) carriers with inherent therapeutic potential.
View Article and Find Full Text PDFAnal Chem
January 2025
Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China.
Herein, a supramolecular DNA nanodevice was formed via the rolling circle amplification (RCA) and hybridization chain reaction (HCR) cascade reaction on a tetrahedral DNA nanostructure (TDN) to achieve simultaneous sensitive detection and intracellular imaging of dual-miRNAs related to liver cancer. The supramolecular DNA nanodevice effectively addressed the limitations of low probe loading capacity in traditional TDN nanodevices by enriching plenty of signal probes around a single TDN, significantly enhancing the fluorescence signal. Impressively, the supramolecular DNA nanodevice with a TDN fulcrum and dense DNA structure imparted the nanodevice with strong rigidity, ensuring the stability of the signal probes to decrease aggregation quenching for further increasing the fluorescence response.
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