AI Article Synopsis
- In the SN2 reaction of CH3F and F-, the secondary deuterium kinetic isotope effect (KIE) is calculated to be small (0.98) due to a balance of entropy and enthalpy terms.
- In contrast, the retention SN2 mechanism shows a larger KIE of 1.5, suggesting it can be used to differentiate between the two reaction mechanisms.
- For ion pair reactions between CH3F and LiF, large KIE values are also observed, and all related transition structures exhibit a bent FCF angle affected by deuterium labeling.
Article Abstract
Using conventional transition state theory, the secondary deuterium kinetic isotope effect (KIE) in the inversion SN2 reaction of CH3F and F- is calculated to be small, 0.98 (T = 298 K). This is shown to be the result of a balance among opposing entropy and enthalpy terms. By contrast, KIE in the retention SN2 mechanism is calculated to be large (1.5). Accordingly, KIE is a potential observable for discriminating between the two mechanisms. Large KIE's are also found for the inversion and retention mechanisms of the ion pair reactions between CH3F and LiF. All of the transition structures leading to large KIE's have a bent FCF angle and an imaginary frequency that is sensitive to deuterium labeling.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/ja0487978 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Directed Evolution's Selective Use of Quantum Tunneling in Designed Enzymes─A Combined Theoretical and Experimental Study.
J Phys Chem B
January 2025
Department of Chemistry and Biochemistry, University of Arizona, 1306 East University Boulevard, Tucson, Arizona 85721, United States.
Natural enzymes are powerful catalysts, reducing the apparent activation energy for reactions and enabling chemistry to proceed as much as 10 times faster than the corresponding solution reaction. It has been suggested for some time that, in some cases, quantum tunneling can contribute to this rate enhancement by offering pathways through a barrier inaccessible to activated events. A central question of interest to both physical chemists and biochemists is the extent to which evolution introduces mechanisms below the barrier, or tunneling mechanisms.
View Article and Find Full Text PDFP-P Coupling and Terminal Metal-Phosphorus Intermediates.
J Am Chem Soc
January 2025
Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States.
Terminal metal-phosphorus (M-P) complexes are of significant contemporary interest as potential platforms for P-atom transfer (PAT) chemistry. Decarbonylation of metal-phosphaethynolate (M-PCO) complexes has emerged as a general synthetic approach to terminal M-P complexes. M-P complexes that are stabilized by strong M-P multiple bonds are kinetically persistent and isolable.
View Article and Find Full Text PDFPhotochemistry of Microsolvated Nitrous Acid: Observation of the Water-Separated Complex of Nitric Oxide and Hydroxyl Radical.
J Phys Chem Lett
January 2025
Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433, China.
The photochemistry of nitrous acid (HONO) plays a crucial role in atmospheric chemistry as it serves as a key source of hydroxyl radicals (OH) in the atmosphere; however, our comprehension of the underlying mechanism for the photochemistry of HONO especially in the presence of water is far from being complete as the transient intermediates in the photoreactions have not been observed. Herein, we report the photochemistry of microsolvated HONO by water in a cryogenic N matrix. Specifically, the 1:1 hydrogen-bonded water complex of HONO was facially prepared in the matrix through stepwise photolytic O oxidation of the water complex of imidogen (NH-HO) via the intermediacy of the elusive water complex of peroxyl isomer HNOO.
View Article and Find Full Text PDFCorrigendum: solution and solubility of H atoms at the W/Cu interface (2024 36 465001).
J Phys Condens Matter
January 2025
Aix-Marseille University, CNRS, PIIM, F-13013 Marseille, France.
Metallic interfaces are locations where hydrogen (H) is expected to segregate and lead to the formation and stabilization of defects. This work focuses on the tungsten/copper (W/Cu) interface built according to theWbcc(001)/Cuhcp(112¯0)orientation. H behavior is subsequently determined at the interface and in its vicinity with electronic structure calculations based on the density functional theory.
View Article and Find Full Text PDFMolecular Processes That Control Organic Electrosynthesis in Near-Electrode Microenvironments.
J Am Chem Soc
January 2025
Department of Chemical and Biomolecular Engineering, New York University, Brooklyn, New York 11201, United States.
Electrosynthesis at an industrial scale offers an opportunity to use renewable electricity in chemical manufacturing, accelerating the decarbonization of large-scale chemical processes. Organic electrosynthesis can improve product selectivity, reduce reaction steps, and minimize waste byproducts. Electrochemical synthesis of adiponitrile (ADN) via hydrodimerization of acrylonitrile (AN) is a prominent example of industrial organic electrochemical processes, with annual production reaching 0.
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!