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C-O bond formation in reactions of olefins with oxygen is a long standing challenge in chemistry for which the very complicated-sometimes controversial-mechanistic panorama slows down the design of catalysts for oxygenations. In this regard, the mechanistic details of the oxidation of the complex [Rh(cod)(Ph N )] (1) (cod=1,5-cyclooctadiene) with oxygen to the unique 2-rhodaoxetane compound [{Rh(OC H )(Ph N )} ] (2) has been investigated by DFT calculations. The results of this study provide evidences for a novel bimetallic mechanism in which two rhodium atoms redistribute the four electrons involved in the cleavage of the O=O bond. Furthermore, both oxygen atoms are used to create two new C-O bonds in a controlled fashion with 100 % atom economy. The key intermediates that we have found in this process are a mononuclear open-shell triplet superoxo compound, an open-shell singlet "μ-(peroxo)" derivative, and a closed-shell singlet "bis(μ-oxo)" complex. Some of the findings are used to predict the reactions of Rh complexes with oxygen, exemplified by that of the complex [Rh(cod)(OnapyMe )] (3). Starting from 3, [{Rh(OC H )(OnapyMe )} ] (4) has been prepared and characterized, which represents the second example of a 2-rhodaoxetane compound coming from an oxygenation reaction with oxygen.
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http://dx.doi.org/10.1002/chem.201605959 | DOI Listing |
Environ Pollut
September 2025
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Key Laboratory of Groundwater Pollution Simulation and Control Ministry of Ecology and Environment, Chinese Research Academy of Environmental Sciences, Beiji
Paddy soil represents a critical sink for microplastics (MPs), where frequent redox oscillations from wet-dry alternation can accelerate MPs aging, and alter dissolved organic matter (DOM) composition in paddy soil. However, this process remains poorly understood to date. Here, we systematically investigated the aging of three MPs and their structural effects on DOM in paddy soil during wet-dry alternation.
View Article and Find Full Text PDFChem Sci
August 2025
Department of Chemistry, University of Houston Houston Texas 77204 USA
Quantum mechanical tunnelling significantly influences the reactivity of strained ring systems, yet strategies for controlling such reactivity remain largely unexplored. Here, we identify geminal hyperconjugation, , electron delocalization between σ-bonds attached to a common atom, as a decisive electronic factor in governing heavy-atom tunnelling reactions involving three-membered rings. We illustrate this through a case study of the oxepin (1') ⇌ benzene oxide (1) equilibrium, recently shown to undergo solvent-controlled tunnelling at 3 K (, 2020, , 20318).
View Article and Find Full Text PDFActa Crystallogr E Crystallogr Commun
September 2025
Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, D-38106 Braunschweig, Germany.
In the structure of the title compound, CHN·CHNOS·CHNOS, the central pyridinic rings are approximately coplanar to the benzo-thia-zole moieties. The phenyl groups are appreciably angled to the central rings [inter-planar angles of 57.30 (3)° for the anion and 79.
View Article and Find Full Text PDFJ Phys Chem A
September 2025
School of Environmental Engineering, Henan University of Technology, Zhengzhou, Henan 450001, China.
Hydroxymethyl-methyl-α-lactone (HMML) is a key epoxide precursor in forming tracer compounds 2-methylglyceric acid (2-MG) or 2-methylglyceric acid sulfate (2-MGOS) from isoprene under high-NOx conditions. Despite its importance, the formation and transformation of HMML─particularly under acidic aerosol conditions─are still poorly understood, limiting comprehensive knowledge of secondary organic aerosol (SOA) formation. In this study, quantum chemical calculations, Born-Oppenheimer molecular dynamics (BOMD), and metadynamics (MTD) simulations are employed to investigate both the formation of HMML from methacryloyl peroxynitrate (MPAN) and its interfacial transformation mechanisms on sulfuric acid aerosols.
View Article and Find Full Text PDFJ Am Chem Soc
September 2025
Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States.
Albomycins are unusual sulfur-containing nucleosides from the species of that exhibit potent antibiotic activities against both Gram-negative and Gram-positive bacteria including clinical pathogens. Previous studies demonstrated that the twitch radical SAM enzyme AbmM catalyzes an oxidative sulfur-for-oxygen swapping reaction converting CDP to a 4'-hydroxy-4'-thiocytidine 5'-diphosphate intermediate in the initial step of albomycin biosynthesis. However, the fate of this intermediate in the biosynthetic pathway has remained elusive.
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