(1,2)--Aminoindanol and (1,2)--aminoindanol, denoted as -AI and -AI, are diastereoisomer aromatic aminoalcohols differing by the presence of a weak intramolecular hydrogen bond in -AI, which is absent in -AI. They also differ by the number of conformers under supersonic jet conditions, one for -AI and two for -AI. One-photon and resonance-enhanced two-photon photoelectron circular dichroism (PECD) spectra are obtained for the two molecules. One-photon ionisation above 11 eV results in molecular fragmentation, with very similar fragmentation pathways for -AI and -AI. Identical PECD spectra for different fragments allow associating them with reactions occurring from the same parent ion within the same electronic state. The shape of the PECD spectra is sensitive to configuration, conformation, and intramolecular hydrogen bonding. Two-photon PECD, being conformer specific, shows that the PECDs of the two ring-puckering conformers of -AI have identical signs but different values.
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http://dx.doi.org/10.1039/d4cp04248d | DOI Listing |
Phys Chem Chem Phys
January 2025
Synchrotron Soleil, L'Orme des Merisiers, St. Aubin BP48, F-91192 Gif sur Yvette, France.
(1,2)--Aminoindanol and (1,2)--aminoindanol, denoted as -AI and -AI, are diastereoisomer aromatic aminoalcohols differing by the presence of a weak intramolecular hydrogen bond in -AI, which is absent in -AI. They also differ by the number of conformers under supersonic jet conditions, one for -AI and two for -AI. One-photon and resonance-enhanced two-photon photoelectron circular dichroism (PECD) spectra are obtained for the two molecules.
View Article and Find Full Text PDFNoncovalent carbon bonding (C-bonding), a recently explored σ-hole interaction, has primarily been characterized through X-ray structural and computational studies. Evidence of C-bonds in solution is scarce, especially in highly polar solvents like DMSO where solvation effects typically overshadow weak non-covalent interactions. In this work, we present three novel spiroisatin-based -acyl hydrazones (1-3) in which C-bonds play a critical role in stabilizing the conformation in solution.
View Article and Find Full Text PDFOrg Lett
January 2025
Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
4'-Selective alkylation of nucleosides has been recognized as one of the ideal and straightforward approaches to chemically modified nucleosides, but such a transformation has been scarce and less explored. In this Letter, we combine a visible-light-mediated photoredox catalysis and hydrogen atom transfer (HAT) auxiliary to achieve β-C(sp)-H alkylation of alcohol on tetrahydrofurfuryl alcohol scaffolds and exploit it for 4'-selective alkylation of nucleosides. The reaction involves an intramolecular 1,5-HAT process and stereocontrolled Giese addition of the resultant radicals.
View Article and Find Full Text PDFBiomacromolecules
January 2025
Department of Material Engineering, Indian Institute of Science, Bangalore 560012, Karnataka, India.
Chitosan (CHT) is a known piezoelectric biomacromolecule; however, its usage is limited due to rapid degradation in an aqueous system. Herein, we prepared CHT film via a solvent casting method and cross-linked in an alkaline solution. Sodium hydroxide facilitated deprotonation, leading to increased intramolecular hydrogen bonding and mechanical properties.
View Article and Find Full Text PDFAnal Chim Acta
February 2025
Tianjian Laboratory of Advanced Biomedical Sciences, Institute of Advanced Biomedical Sciences, Henan International Joint Laboratory of Tumor Theranostic Cluster Materials, Henan Key Laboratory of Crystalline Molecular Functional Materials, College of Chemistry, Zhengzhou University, 450001, Zhengzhou, China. Electronic address:
Background: Integrating natural enzymes and nanomaterials exhibiting tailored enzyme-like activities is an effective strategy for the application of cascade reactions. It is essential to develop a highly efficient and robust glucose oxidase-catalase (GOx-CAT) cascade system featuring controllable enzyme activity, a reliable supply of oxygen, and improved stability for glucose depletion in cancer starvation therapy. However, the ambiguous relationship between structure and performance, and the difficulty in controlling enzyme-mimic activity, significantly hinder their broader application.
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