The title metallacrown (MC) complexes Ln[15-MC-5](OAc)CI(CHN) (), where OAc is acetate, shi is salicylhydroximate, and Ln = Gd and Dy, were synthesized via a self-assembly reaction in methanol and pyridine. Single crystals were grown using slow evaporation and characterized using X-ray diffraction. Seven-coordinate capped octahedron geometries were observed for the lanthanide ion in both complexes, which is uncommon for trivalent lanthanide species. The 15-MC-5 is a ruffled metallacrown archetype similar to previously reported mixed-valent manganese metallacrowns.
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http://dx.doi.org/10.1007/s10870-021-00900-6 | DOI Listing |
J Phys Chem Lett
January 2025
Centre for Hyperpolarization in Magnetic Resonance, University of York, Heslington YO10 5NY, United Kingdom.
This research uses perfluorocarbons (PFCs) as effective alternatives to traditional toxic solvents in reversible -hydrogen-induced polarization (PHIP) for NMR signal enhancement. Hydrogen solubility in PFCs is shown here to be an order of magnitude higher than in typical organic solvents by determination of Henry's constants. We demonstrate how this high H solubility enables the PFCs to deliver substantial polarization transfer from -hydrogen, achieving up to 2400-fold signal gains for H NMR detection and 67,000-fold (22% polarization) for N NMR detection at 9.
View Article and Find Full Text PDFChemistryOpen
January 2025
Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Department of Chemistry, Ciudad Autónoma de Buenos Aires, 1113, Argentina.
Gem-diols are defined as organic molecules carrying two hydroxyl groups at the same carbon atom, which is the result of the nucleophilic addition of water to a carbonyl group. In this work, the generation of the hydrated or hemiacetal forms using pyridine- and imidazole-carboxaldehyde isomers in different chemical environments was studied by Nuclear Magnetic Resonance (NMR) recorded in different media and combined with theoretical calculations. The change in the position of aldehyde group in either the pyridine or the imidazole ring had a clear effect in the course of the hydration/hemiacetal generation reaction, which was favored in protic solvents mainly in the presence of methanol.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
December 2024
Department of Life Science and Technology: Tokyo Kogyo Daigaku Seimei Rikogakuin Seimei Rikogakukei, Institute of Science Tokyo, 4259 Nagatsuta-Cho Midzeori-Ku, Yokohama, 226-8501, Japan.
Chiral diaryl alcohols, such as (4-chlorophenyl)(pyridin-2-yl)methanol, are important intermediates for pharmaceutical synthesis. However, using alcohol dehydrogenases (ADHs) in the asymmetric reduction of diaryl ketones to produce the corresponding alcohols is challenging due to steric hindrance in the substrate binding pockets of the enzymes. In this study, the steric hindrance of the ADH from Geotrichum candidum NBRC 4597 (G.
View Article and Find Full Text PDFActa Crystallogr E Crystallogr Commun
October 2024
Department of Chemistry, Taras Shevchenko National University of Kyiv, Volodymyrska Street 64, Kyiv, 01601, Ukraine.
The unit cell of the title compound, [Ni(CHClN)]·2CHOH, consists of a neutral complex and two methanol mol-ecules. In the complex, the two tridentate 2-(3-(4-chloro-phen-yl)-1-1,2,4-triazol-5-yl)-6-(1-pyrazol-1-yl)pyridine ligands coordinate to the central Ni ion through the N atoms of the pyrazole, pyridine and triazole groups, forming a pseudo-octa-hedral coordination sphere. Neighbouring tapered mol-ecules are linked through weak C-H(pz)⋯π(ph) inter-actions into monoperiodic chains, which are further linked through weak C-H⋯N/C inter-actions into diperiodic layers.
View Article and Find Full Text PDFNanomaterials (Basel)
November 2024
Electrochemistry Department, St. Petersburg State University, 7/9 Universitetskaya nab., 199034 St. Petersburg, Russia.
The oxygen reduction reaction (ORR) plays a central role in energy conversion and storage technologies. A promising alternative to precious metal catalysts are non-precious metal doped carbons. Considerable efforts have been devoted to cobalt-doped carbonized polyacrylonitrile catalysts, but the optimization of their catalytic performance remains a key challenge.
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