Journal of Molecular Modeling, Год журнала: 2024, Номер 30(11)
Опубликована: Окт. 3, 2024
Язык: Английский
Journal of the American Chemical Society, Год журнала: 2024, Номер 146(10), С. 6866 - 6879
Опубликована: Март 4, 2024
Activity descriptors are a powerful tool for the design of catalysts that can efficiently utilize H2 with minimal energy losses. In this study, we develop use hydricity and H– self-exchange rates as thermodynamic kinetic hydrogenation ketones by molecular catalysts. Two complexes known hydricity, HRh(dmpe)2 HCo(dmpe)2, were investigated catalytic under mild conditions (1.5 atm 25 °C). The rhodium catalyst proved to be an efficient wide range ketones, whereas cobalt could only hydrogenate electron-deficient ketones. Using combination experiment electronic structure theory, values established 46 alkoxide/ketone pairs in both acetonitrile tetrahydrofuran solvents. Through comparison hydricities substrates, it was determined catalysis observed catalyst/ketone exergonic transfer step. Mechanistic studies revealed rate-limiting step catalysis, allowing experimental computation construction linear free-energy relationships (LFERs) transfer. Further analysis LFERs reproduced using Marcus which HRh/Rh+ ketone/alkoxide used predict experimentally measured barriers within 2 kcal mol–1. These significantly expand scope reactions analyzed descriptor firmly establish theory valid approach designing reactions.
Язык: Английский
Процитировано
8
Chemical Science, Год журнала: 2024, Номер 15(11), С. 3980 - 3987
Опубликована: Янв. 1, 2024
The origin of the electrophilicity a series cyclohexanones and benzaldehydes is investigated using activation strain model quantitative Kohn–Sham molecular orbital (MO) theory.
Язык: Английский
Процитировано
7
Journal of Chemical Theory and Computation, Год журнала: 2023, Номер 19(20), С. 7300 - 7306
Опубликована: Окт. 4, 2023
Understanding the geometrical preferences in chemical reactions is crucial for advancing field of organic chemistry and improving synthetic strategies. One such preference, Bürgi-Dunitz angle, central to nucleophilic addition involving carbonyl groups. This study successfully employs a novel two-dimensional Distortion-Interaction/Activation-Strain Model combination with Energy Decomposition Analysis investigate origins angle reaction CN- (CH3)2C═O. We constructed 2D potential energy surface defined by distance between nucleophile carbonylic carbon atom attack followed an in-depth exploration components, including strain interaction energy. Our analysis reveals that emerges from delicate balance two key factors: High energy, as result compound distorting avoid Pauli repulsion, encountered at high angles, thus setting upper bound. On other hand, shaped dominant repulsion when angles are lower. work emphasizes value refined tool, offering both quantitative qualitative insights into reactivity selectivity.
Язык: Английский
Процитировано
11
The Journal of Physical Chemistry A, Год журнала: 2025, Номер unknown
Опубликована: Март 22, 2025
We report an atypical competition between fenchyl radical β-scission and peroxidation at low temperatures unravel the impacts of strain energy ring substituent location on their respective contributions. Our RRKM modeling reveals that radicals positioned secondary carbons are fastest-scission ones, exhibiting maximum local relief. Dimethyl substituents contribute to increased compared norbornane, hindering bridge scission leading cyclopentene isoprene products. The dimethyl corset generates extra torsional during HO2 elimination from QOOH, while ether formation is favored by electron donation carbonyl group. falloff extent also affected steric hindrance, insofar as it increases stiffness, a lower vibrational partition function low-pressure rate constant. Furthermore, methyl-induced restrictions reactant reorganization found modulate enthalpy–entropy compensation in Korcek reaction hydroperoxide. Unlike our previous stirred reactor experiments, impact reactivity notable under new rapid compression machine (RCM) experiments. present model predicts contrasted selectivities with position, prevailing respectively for F1/F2/F3/F4 F5/F6 radicals. kinetic mechanism accurately experimental IDT but indicates slight first-stage pressure inflection point temperature, which could not be confirmed experimentally. This insight into fenchone ring-opening -closing mechanisms high-pressure oxidation can useful other polycyclic ketones.
Язык: Английский
Процитировано
0
Structural Dynamics, Год журнала: 2024, Номер 11(2)
Опубликована: Март 1, 2024
With the availability of computer readable information in Cambridge Structural Database (CSD), wide ranging, largely automated comparisons fragment, molecular, and crystal structures have become possible. They show that distributions interatomic distances, angles, torsion angles for a given structural fragment occurring different environments are highly correlated among themselves with other observables such as spectroscopic signals, reaction activation energies. The correlations often extend continuously over large ranges parameter values. reminiscent bond breaking forming reactions, polyhedral rearrangements, conformational changes. map-qualitatively-the regions space which molecular dynamics take place, namely, low energy respective (free) surfaces. extension continuous nature provides an organizing principle groups data suggests reconsideration traditional definitions descriptions bonds, "nonbonded" "noncovalent" interactions terms Lewis acids interacting bases. These aspects illustrated selected examples historic importance some later developments. It seems amount CSD (and databases) knowledge on of, within, this body should allow one-in near future-to make credible interpolations possibly predictions their properties machine learning methods.
Язык: Английский
Процитировано
3
Chemistry - An Asian Journal, Год журнала: 2024, Номер 19(5)
Опубликована: Фев. 23, 2024
Abstract Halogen bonds are typically observed to have a linear arrangement with 180° angle between the nucleophile and halogen bond acceptor X−R. This linearity is commonly explained using σ‐hole model, although there been alternative explanations involving exchange repulsion forces. We employ two‐dimensional Distortion/Interaction Energy Decomposition Analysis examine archetypal H 3 N⋯X 2 systems. Our results indicate that predominantly electrostatic, their directionality largely due decreased Pauli in configurations as opposed angled ones I Br As we move smaller halogens, Cl F , influence of diminishes, energy surface shaped by orbital interactions electrostatic These support role forces influencing strong bonds. Additionally, demonstrate 2D useful tool for enhancing our understanding nature potential surfaces noncovalent interactions.
Язык: Английский
Процитировано
2
Chemical Science, Год журнала: 2024, Номер 15(31), С. 12380 - 12387
Опубликована: Янв. 1, 2024
The origin of the widely used Felkin–Anh(–Eisentein) model is quantitatively analyzed in detail by means state-of-the-art computational methods.
Язык: Английский
Процитировано
2
The Journal of Organic Chemistry, Год журнала: 2024, Номер 89(2), С. 957 - 974
Опубликована: Янв. 4, 2024
The isocyanide group is the chameleon among functional groups in organic chemistry. Unlike other multiatom groups, where electrophilic and nucleophilic moieties are typically separated, isocyanides combine both functionalities terminal carbon. This unique feature can be rationalized using frontier orbital concept has significant implications for its intermolecular interactions reactivity of group. In this study, we perform a Cambridge Crystallographic Database-supported analysis intramolecular to investigate solid state, excluding isocyanide–metal complexes. We discuss examples different interaction classes, including as hydrogen bond acceptor (RNC···HX), halogen bonding (RNC···X), involving carbon atoms (RNC···C). latter serves an intriguing illustration Bürgi–Dunitz trajectory represents crucial experimental detail well-known multicomponent reactions such Ugi- Passerini-type mechanisms. Understanding spectrum that undergo holds fields medicinal chemistry, materials science, asymmetric catalysis.
Язык: Английский
Процитировано
1
Comptes Rendus Chimie, Год журнала: 2024, Номер 27(S2), С. 5 - 19
Опубликована: Март 6, 2024
Nucleophilic addition to carbonyl groups is one of the most important reactions in organic synthesis. In case a prochiral group, preference for nucleophile face π system leads unequal amounts two possible diastereoisomers. The mechanism this reaction various nucleophiles (especially early main group hydride and Grignard reagents) noncyclic cyclic aldehydes or ketones has fascinated computational chemists nearly 40 years. This article describes research that been done on topic, incentive present author being she started her with topic returning it recent L'addition d'un nucléophile sur un composé carbonylé est une des réactions essentielles en synthèse organique. Si le groupe carbonyle prochiral, l'addition les deux faces du système ne sont pas équivalentes et la réaction conduit à excès diastéréoisomères. Le mécanisme de ces pour divers nucléophiles (hydrures éléments principal réactifs type particulier) aldéhydes ou cétones cycliques non attiré l'attention nombreux théoriciens depuis pratiquement ans. Cet décrit l'historique recherches dans ce domaine. L'auteure s'est intéressée sujet car elle entrée recherche avec domaine y revenue toutes dernières années.
Процитировано
1
Опубликована: Авг. 16, 2023
Understanding the geometrical preferences in chemical reactions is crucial for advancing field of organic chemistry and improving synthetic strategies. One such preference, Bürgi-Dunitz angle, central to nucleophilic addition involving carbonyl groups. This study successfully employs a novel two-dimensional Distortion-Interaction/Activation-Strain Model combination with Energy Decomposition Analysis investigate origins angle reaction CN– (CH3)2C=O. We constructed 2D potential energy surface defined by distance between nucleophile carbonylic carbon atom attack followed an in-depth exploration components including strain interaction energy. Our analysis reveals that emerges from delicate balance two key factors: High energy, as result compound distorting avoid Pauli repulsion, encountered at high angles, thus setting upper bound. On other hand, shaped dominant repulsion when angles are lower. work emphasizes value refined tool, offering both quantitative qualitative insights into reactivity selectivity.
Язык: Английский
Процитировано
1