The synthesis of gallophosphate cloverite in the presence of aluminium leads to a partial substitution of Ga by Al. 27Al and 19F magic-angle spinning nuclear magnetic resonance (MAS NMR) studies on this material confirm this substitution. 27Al MAS NMR shows a broad line at 30 ppm which can be attributed to tetrahedrally coordinated Al in the solid. The 19F MAS NMR results are more complex. The spectrum presents five lines between -68 ppm and -95 ppm which can be assigned to fluorine in D4Rs with variable composition in Ga and Al. Two other lines, at -145.6 ppm and -178.2 ppm, may correspond to impurities and to a fluorine atom in a pseudo-sodalite cage environment, respectively.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/0926-2040(94)90051-5 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Construction of Luminescent Three-Dimensional Covalent Organic Frameworks for Molecular Decoding of Wide Organic Compounds.
Chem Asian J
January 2025
Qingdao University of Science and Technology, College of Polymer Science and Engineering, 53 ZHENGZHOU ROAD, 266000, Qingdao, CHINA.
Constructing highly conjugated three-dimensional covalent organic frameworks (3D COFs), particularly those with luminescent features, remains a significant challenge. In this work, we successfully synthesized a 3D COF, named 3D-Py-SP-COF, using a rigid and orthogonal spirobifluorene building block for the spatial 3D structure construction and planar pyrene as luminescent units. The incorporation of the pyrene and the unique rigid 3D network structure endow 3D-Py-SP-COF with fluorescent properties.
View Article and Find Full Text PDFOlive Fruit Phenolic Profiling Using High Resolution-Magic Angle Spinning (HR-MAS) Solid-State NMR Spectroscopy.
Methods Mol Biol
January 2025
NMR Laboratory, Chemistry Department, University of Crete, Heraklion, Crete, Greece.
High Resolution-Magic Angle Spinning (HR-MAS) solid-state NMR spectroscopy is finding increasing application in the analysis of solid foods, bypassing the need for complicated solvent extraction procedures. In the present protocol, we report a simple analytical approach based on HR-MAS NMR spectroscopy for the phenolic profiling of olive fruits, flesh, or skin. This approach allows the facile characterization of phenolic compounds in olive fruits cultivated for extra-virgin olive oil production as a function of maturation and variety, in addition to processing technology for table olives.
View Article and Find Full Text PDFDACH-Based Chiral Sensing Platforms as Tunable Benzamide-Chiral Solvating Agents for NMR Enantioselective Discrimination.
Anal Chem
January 2025
School of Petrochemical Engineering, Liaoning Petrochemical University, Fushun 113001, China.
Chiral discrimination is an indispensable tool that has pivotal importance in the assignment of absolute configuration and determination of enantiomeric excess in chiral compounds. A series of enantiomerically pure -1,2-diaminocyclohexane (-DACH)-derived benzamides were first synthesized by simple chemical steps, and 14 variated derivatives have been assessed as NMR chiral solvating agents (CSAs) for discrimination of the signals of mandelic acid (MA) in H NMR analysis. The highly efficient chiral recognition of CSA on different substrates, including MAs, carboxylic acids, amino acid derivatives, and phosphoric acids (32 examples), was expanded via H, F, and P NMR spectroscopy.
View Article and Find Full Text PDFInvestigating Cell Wall Diffusion in Wood Modified with Phenol Urea Formaldehyde Resin in Different Length Scales.
Biomacromolecules
January 2025
BioComposites Centre, Bangor University, Bangor LL57 2UW, U.K.
Wood modification using low molecular weight thermosetting resins improves the biological durability and dimensional stability of wood while avoiding increasingly regulated biocides. During the modification process, resin monomers diffuse from the cell lumen to the cell wall, occupying micropore spaces before curing at 150 °C. This study investigated the mechanism of cell wall diffusion at multiple scales, comparing two test groups where diffusion was either facilitated or restricted.
View Article and Find Full Text PDFOptimization of the Heterogeneous Synthesis Conditions for Cellulose Tosylation and Synthesis of a Propargylamine Cellulosic Derivative.
Polymers (Basel)
December 2024
Institute of Chemistry, Federal University of Uberlândia, Uberlândia 38400-902, Brazil.
Cellulose tosylate (MCC-Tos) is a key derivative for surface modification and a crucial precursor for cellulose compatibilization in click reactions, enabling its functionalization for advanced applications. Replacing tosyl groups with alkyne groups broadens cellulose's potential in biocompatible reactions, such as thiol-yne click chemistry and protein/enzyme immobilization. To achieve this, we optimized the heterogeneous synthesis of MCC-Tos using a Doehlert matrix statistical design, evaluating the influence and interaction of the reaction conditions.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!