1
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Qiu L, Cooks RG. Spontaneous Oxidation in Aqueous Microdroplets: Water Radical Cation as Primary Oxidizing Agent. Angew Chem Int Ed Engl 2024; 63:e202400118. [PMID: 38302696 DOI: 10.1002/anie.202400118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 01/28/2024] [Accepted: 01/29/2024] [Indexed: 02/03/2024]
Abstract
Exploration of the unique chemical properties of interfaces can unlock new understanding. A striking example is the finding of accelerated reactions, particularly spontaneous oxidation reactions, that occur without assistance of catalysts or external oxidants at the air interface of both aqueous and organic solutions (provided they contain some water). This finding opened a new area of interfacial chemistry but also caused heated debate regarding the primary chemical species responsible for the observed oxidation. An overview of the literature covering oxidation in microdroplets with air interfaces is provided, together with a critical examination of previous findings and hypotheses. The water radical cation/radical anion pair, formed spontaneously and responsible for the electric field at or near the droplet/air interface, is suggested to constitute the primary redox species. Mechanisms of accelerated microdroplet reactions are critically discussed and it is shown that hydroxyl radical/hydrogen peroxide formation in microdroplets does not require that these species be the primary oxidant. Instead, we suggest that hydroxyl radical and hydrogen peroxide are the products of water radical cation decay in water. The importance of microdroplet chemistry in the prebiotic environment is sketched briefly and the role of partial solvation in reaction acceleration is noted.
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Affiliation(s)
- Lingqi Qiu
- Department of Chemistry, Purdue University, West Lafayette, IN 47907, U.S
| | - R Graham Cooks
- Department of Chemistry, Purdue University, West Lafayette, IN 47907, U.S
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2
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Wu X, Bickelhaupt FM, Xie J. Solvent-induced dual nucleophiles and the α-effect in the S N2 versus E2 competition. Phys Chem Chem Phys 2024; 26:11320-11330. [PMID: 38536735 PMCID: PMC11022550 DOI: 10.1039/d4cp00671b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 03/14/2024] [Indexed: 04/18/2024]
Abstract
We have quantum chemically investigated how microsolvation affects the various E2 and SN2 pathways, their mutual competition, and the α-effect of the model reaction system HOO-(H2O)n + CH3CH2Cl, at the CCSD(T) level. Interestingly, we identify the dual nature of the α-nucleophile HOO- which, upon solvation, is in equilibrium with HO-. This solvent-induced dual appearance gives rise to a rich network of competing reaction channels. Among both nucleophiles, SN2 is always favored over E2, and this preference increases upon increasing microsolvation. Furthermore, we found a pronounced α-effect, not only for SN2 substitution but also for E2 elimination, i.e., HOO- is more reactive than HO- in both cases. Our activation strain and quantitative molecular orbital analyses reveal the physical mechanisms behind the various computed trends. In particular, we demonstrate that two recently proposed criteria, required for solvent-free nucleophiles to display the α-effect, must also be satisfied by microsolvated HOO-(H2O)n nucleophiles.
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Affiliation(s)
- Xiangyu Wu
- Key Laboratory of Cluster Science of Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, China.
| | - F Matthias Bickelhaupt
- Department of Chemistry and Pharmaceutical Sciences, AIMMS, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands.
- Institute for Molecules and Materials (IMM), Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
- Department of Chemical Sciences, University of Johannesburg, Auckland Park, Johannesburg 2006, South Africa
| | - Jing Xie
- Key Laboratory of Cluster Science of Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, China.
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3
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Ben-Amotz D. Interfacial chemical reactivity enhancement. J Chem Phys 2024; 160:084704. [PMID: 38391019 DOI: 10.1063/5.0186945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 01/16/2024] [Indexed: 02/24/2024] Open
Abstract
Interfacial enhancements of chemical reaction equilibria and rates in liquid droplets are predicted using a combined theoretical and experimental analysis strategy. Self-consistent solutions of reaction and adsorption equilibria indicate that interfacial reactivity enhancement is driven primarily by the adsorption free energy of the product (or activated complex). Reactant surface activity has a smaller indirect influence on reactivity due to compensating reactant interfacial concentration and adsorption free energy changes, as well as adsorption-induced depletion of the droplet core. Experimental air-water interfacial adsorption free energies and critical micelle concentration correlations provide quantitative surface activity estimates as a function of molecular structure, predicting an increase in interfacial reactivity with increasing product size and decreasing product polarity, aromaticity, and charge (but less so for anions than cations). Reactions with small, neutral, or charged products are predicted to have little reactivity enhancement at an air-water interface unless the product is rendered sufficiently surface active by, for example, interactions with interfacial water dangling OH groups, charge transfer, or voltage fluctuations.
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Affiliation(s)
- Dor Ben-Amotz
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA
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4
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Castaldo D, Jahangiri S, Delgado A, Corni S. Quantum Simulation of Molecules in Solution. J Chem Theory Comput 2022; 18:7457-7469. [PMID: 36351289 DOI: 10.1021/acs.jctc.2c00974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Quantum chemical calculations on quantum computers have been focused mostly on simulating molecules in the gas phase. Molecules in liquid solution are, however, most relevant for chemistry. Continuum solvation models represent a good compromise between computational affordability and accuracy in describing solvation effects within a quantum chemical description of solute molecules. In this work, we extend the variational quantum eigensolver to simulate solvated systems using the polarizable continuum model. To account for the state dependent solute-solvent interaction we generalize the variational quantum eigensolver algorithm to treat non-linear molecular Hamiltonians. We show that including solvation effects does not impact the algorithmic efficiency. Numerical results of noiseless simulations for molecular systems with up to 12 spin-orbitals (qubits) are presented. Furthermore, calculations performed on a simulated noisy quantum hardware (IBM Q, Mumbai) yield computed solvation free energies in fair agreement with the classical calculations.
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Affiliation(s)
- Davide Castaldo
- Dipartimento di Scienze Chimiche, Università degli studi di Padova, Via Marzolo 1, Padova35131, Italy
| | | | | | - Stefano Corni
- Dipartimento di Scienze Chimiche, Università degli studi di Padova, Via Marzolo 1, Padova35131, Italy.,Istituto Nanoscienze─CNR, via Campi 213/A, Modena41125, Italy.,Padua Quantum Technologies Research Center, Università di Padova, Padova35131, Italy
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5
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Taylor M, Yu H, Ho J. Predicting Solvent Effects on S N2 Reaction Rates: Comparison of QM/MM, Implicit, and MM Explicit Solvent Models. J Phys Chem B 2022; 126:9047-9058. [PMID: 36300819 DOI: 10.1021/acs.jpcb.2c06000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Solvents are one of the key variables in the optimization of a synthesis yield or properties of a synthesis product. In this paper, contemporary solvent models are applied to predict the rates of SN2 reactions in a range of aqueous and non-aqueous solvents. High-level CCSD(T)/CBS//M06-2X/6-31+G(d) gas phase energies were combined with solvation free energies from SMD, SM12, and ADF-COSMO-RS continuum solvent models, as well as molecular mechanics (MM) explicit solvent models with different atomic charge schemes to predict the rate constants of three SN2 reactions in eight protic and aprotic solvents. It is revealed that the prediction of rate constants in organic solvents is not necessarily less challenging than in water and popular solvent models struggle to predict their rate constants to within 3 log units of experimental values. Among the continuum solvent models, the ADF-COSMO-RS model performed the best in predicting absolute rate contants while the SM12 model was best at predicting relative rate constants with an average accuracy of about 1.5 and 0.8 log units, respectively. The use of computationally more demanding MM explicit solvent models did not translate to improvements in absolute rate constants but was quite effective at predicting relative rate constants due to systematic error cancellation. Free energy barriers obtained from umbrella sampling with explicit solvent QM/MM simulations led to excellent agreement with experimental values, provided that a validated level of theory is used to treat the QM region.
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Affiliation(s)
- Mackenzie Taylor
- School of Chemistry, The University of New South Wales, Sydney, New South Wales2052, Australia
| | - Haibo Yu
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales2522, Australia
| | - Junming Ho
- School of Chemistry, The University of New South Wales, Sydney, New South Wales2052, Australia
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6
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Robinson HT, Corkish TR, Haakansson CT, Watson PD, McKinley AJ, Wild DA. Spectroscopic Study of the Br - +CH 3 I→I - +CH 3 Br S N 2 Reaction. Chemphyschem 2022; 23:e202200278. [PMID: 35708114 PMCID: PMC9804238 DOI: 10.1002/cphc.202200278] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 06/06/2022] [Indexed: 01/05/2023]
Abstract
Mass spectrometry and anion photoelectron spectroscopy have been used to study the gas-phase <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics> <mml:mrow><mml:msub><mml:mi>S</mml:mi> <mml:mi>N</mml:mi></mml:msub> <mml:mn>2</mml:mn></mml:mrow> <mml:annotation>${{{\rm S}}_{{\rm N}}2}$</mml:annotation> </mml:semantics> </mml:math> reaction involving <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics> <mml:msup><mml:mrow><mml:mi>B</mml:mi> <mml:mi>r</mml:mi></mml:mrow> <mml:mo>-</mml:mo></mml:msup> <mml:annotation>${{{\rm B}{\rm r}}^{-}}$</mml:annotation> </mml:semantics> </mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics> <mml:mrow> <mml:msub><mml:mrow><mml:mi>C</mml:mi> <mml:mi>H</mml:mi></mml:mrow> <mml:mn>3</mml:mn></mml:msub> <mml:mi>I</mml:mi></mml:mrow> <mml:annotation>${{{\rm C}{\rm H}}_{3}{\rm I}}$</mml:annotation> </mml:semantics> </mml:math> . The anion photoelectron spectra associated with the reaction intermediates of this <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics> <mml:mrow><mml:msub><mml:mi>S</mml:mi> <mml:mi>N</mml:mi></mml:msub> <mml:mn>2</mml:mn></mml:mrow> <mml:annotation>${{{\rm S}}_{{\rm N}}2}$</mml:annotation> </mml:semantics> </mml:math> reaction are presented. High-level CCSD(T) calculations have been utilised to investigate the reaction intermediates that may form as a result of the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics> <mml:mrow><mml:msub><mml:mi>S</mml:mi> <mml:mi>N</mml:mi></mml:msub> <mml:mn>2</mml:mn></mml:mrow> <mml:annotation>${{{\rm S}}_{{\rm N}}2}$</mml:annotation> </mml:semantics> </mml:math> reaction along various different reaction pathways, including back-side attack and front-side attack. In addition, simulated vertical detachment energies of each reaction intermediate have been calculated to rationalise the photoelectron spectra.
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Affiliation(s)
- Hayden T. Robinson
- School of Molecular SciencesThe University of Western AustraliaCrawleyWestern Australia6009
| | - Timothy R. Corkish
- School of Molecular SciencesThe University of Western AustraliaCrawleyWestern Australia6009
| | | | - Peter D. Watson
- School of Molecular SciencesThe University of Western AustraliaCrawleyWestern Australia6009,Department of ChemistryUniversity of OxfordSouth Parks RoadOxfordUnited KingdomOX1 3QZ
| | - Allan J. McKinley
- School of Molecular SciencesThe University of Western AustraliaCrawleyWestern Australia6009
| | - Duncan A. Wild
- School of Molecular SciencesThe University of Western AustraliaCrawleyWestern Australia6009,School of ScienceEdith Cowan UniversityJoondalupWestern Australia6027
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7
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Unexpected steric hindrance failure in the gas phase F - + (CH 3) 3CI S N2 reaction. Nat Commun 2022; 13:4427. [PMID: 35907925 PMCID: PMC9338938 DOI: 10.1038/s41467-022-32191-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 07/18/2022] [Indexed: 11/13/2022] Open
Abstract
Base-induced elimination (E2) and bimolecular nucleophilic substitution (SN2) reactions are of significant importance in physical organic chemistry. The textbook example of the retardation of SN2 reactivity by bulky alkyl substitution is widely accepted based on the static analysis of molecular structure and steric environment. However, the direct dynamical evidence of the steric hindrance of SN2 from experiment or theory remains rare. Here, we report an unprecedented full-dimensional (39-dimensional) machine learning-based potential energy surface for the 15-atom F− + (CH3)3CI reaction, facilitating the reliable and efficient reaction dynamics simulations that can reproduce well the experimental outcomes and examine associated atomic-molecular level mechanisms. Moreover, we found surprisingly high “intrinsic” reactivity of SN2 when the E2 pathway is completely blocked, indicating the reaction that intends to proceed via E2 transits to SN2 instead, due to a shared pre-reaction minimum. This finding indicates that the competing factor of E2 but not the steric hindrance determines the small reactivity of SN2 for the F− + (CH3)3CI reaction. Our study provides new insight into the dynamical origin that determines the intrinsic reactivity in gas-phase organic chemistry. Base-induced elimination (E2) and bimolecular nucleophilic substitution (SN2) are of significant importance in physical organic chemistry. Here, the authors show that the competing factor of E2 as opposed to steric hindrance determines the low reactivity of SN2 in the F− + (CH3)3CI reaction.
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8
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Panapitiya G, Girard M, Hollas A, Sepulveda J, Murugesan V, Wang W, Saldanha E. Evaluation of Deep Learning Architectures for Aqueous Solubility Prediction. ACS OMEGA 2022; 7:15695-15710. [PMID: 35571767 PMCID: PMC9096921 DOI: 10.1021/acsomega.2c00642] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 04/11/2022] [Indexed: 05/17/2023]
Abstract
Determining the aqueous solubility of molecules is a vital step in many pharmaceutical, environmental, and energy storage applications. Despite efforts made over decades, there are still challenges associated with developing a solubility prediction model with satisfactory accuracy for many of these applications. The goals of this study are to assess current deep learning methods for solubility prediction, develop a general model capable of predicting the solubility of a broad range of organic molecules, and to understand the impact of data properties, molecular representation, and modeling architecture on predictive performance. Using the largest currently available solubility data set, we implement deep learning-based models to predict solubility from the molecular structure and explore several different molecular representations including molecular descriptors, simplified molecular-input line-entry system strings, molecular graphs, and three-dimensional atomic coordinates using four different neural network architectures-fully connected neural networks, recurrent neural networks, graph neural networks (GNNs), and SchNet. We find that models using molecular descriptors achieve the best performance, with GNN models also achieving good performance. We perform extensive error analysis to understand the molecular properties that influence model performance, perform feature analysis to understand which information about the molecular structure is most valuable for prediction, and perform a transfer learning and data size study to understand the impact of data availability on model performance.
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9
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Ji X, Xie J. Proton transfer-induced competing product channels of microsolvated Y -(H 2O) n + CH 3I (Y = F, Cl, Br, I) reactions. Phys Chem Chem Phys 2022; 24:7539-7550. [PMID: 35289813 DOI: 10.1039/d1cp04873b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The potential energy profiles of three proton transfer-involved product channels for the reactions of Y-(H2O)1,2 + CH3I (Y = F, Cl, Br, I) were characterized using the B97-1/ECP/d method. These three channels include the (1) PTCH3 product channel that transfers a proton from methyl to nucleophile, (2) HO--induced nucleophilic substitution (HO--SN2) product channel, and (3) oxide ion substitution (OIS) product channel that gives CH3O- and HY products. The reaction enthalpies and barrier heights follow the order OIS > PTCH3 > HO--SN2 > Y--SN2, and thus HO--SN2 can compete with the most favored Y--SN2 product channel under singly-/doubly-hydrated conditions, while the PTCH3 channel only occurs under high collision energy and the OIS channel is the least probable. All product channels share the same pre-reaction complex, Y-(H2O)n-CH3I, in the entrance of the potential energy profile, signifying the importance of the pre-reaction complex. For HO-/Y--SN2 channels, we considered front-side attack, back-side attack, and halogen-bonded complex mechanisms. Incremental hydration increases the barriers of both HO-/Y--SN2 channels as well as their barrier difference, implying that the HO--SN2 channel becomes less important when further hydrated. Varying the nucleophile Y- from F- to I- also increases the barrier heights and barrier difference, which correlates with the proton affinity of the nucleophiles. Energy decomposition analyses show that both the orbital interaction energy and structural deformation energy of the transition states determine the SN2 barrier change trend with incremental hydration and varying Y-. In brief, this work computes the comprehensive potential energy surfaces of the HO--SN2 and PTCH3 channels and shows how proton transfer affects the microsolvated Y-(H2O)1,2 + CH3I reaction by competing with the traditional Y--SN2 channel.
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Affiliation(s)
- Xiaoyan Ji
- Key Laboratory of Cluster Science of Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China.
| | - Jing Xie
- Key Laboratory of Cluster Science of Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China.
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10
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Abstract
Ufmylation is a post-translational modification essential for regulating key cellular processes. A three-enzyme cascade involving E1, E2 and E3 is required for UFM1 attachment to target proteins. How UBA5 (E1) and UFC1 (E2) cooperatively activate and transfer UFM1 is still unclear. Here, we present the crystal structure of UFC1 bound to the C-terminus of UBA5, revealing how UBA5 interacts with UFC1 via a short linear sequence, not observed in other E1-E2 complexes. We find that UBA5 has a region outside the adenylation domain that is dispensable for UFC1 binding but critical for UFM1 transfer. This region moves next to UFC1’s active site Cys and compensates for a missing loop in UFC1, which exists in other E2s and is needed for the transfer. Overall, our findings advance the understanding of UFM1’s conjugation machinery and may serve as a basis for the development of ufmylation inhibitors. Ufmylation is a well-established ubiquitin-like protein modification, but its mechanism is largely unclear. Here, the authors present a crystal structure of the ufmylation-specific E1-E2 complex, revealing differences to the ubiquitination machinery and mechanistic details of the ufmylation process.
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11
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Gallegos M, Costales A, Pendás ÁM. Energetic Descriptors of Steric Hindrance in Real Space: An Improved IQA Picture*. Chemphyschem 2021; 22:775-787. [PMID: 33497008 DOI: 10.1002/cphc.202000975] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/05/2021] [Indexed: 11/11/2022]
Abstract
Steric hindrance (SH) plays a central role in the modern chemical narrative, lying at the core of chemical intuition. As it however happens with many successful chemical concepts, SH lacks an underlying physically sound root, and multiple mutually inconsistent approximations have been devised to relate this fuzzy concept to computationally derivable descriptors. We here argue that being SH related to spatial as well as energetic features of interacting systems, SH can be properly handled if we chose a real space energetic stance like the Interacting Quantum Atoms (IQA) approach. Drawing on previous work by Popelier and coworkers (ChemistryOpen 8, 560, 2019) we build an energetic estimator of SH, referred to as EST . We show that the rise in the self-energy of a fragment that accompanies steric congestion is a faithful proxy for the chemist's SH concept if we remove the effect of charge transfer. This can be done rigorously, and the EST here defined provides correct sterics even for hydrogen atoms, where the plain use of deformation energies leads to non-chemical results. The applicability of EST is validated in several chemical scenarios, going from atomic compressions to archetypal SN2 reactions. EST is shown to be a robust steric hindrance descriptor.
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Affiliation(s)
- Miguel Gallegos
- Department of Analytical and Physical Chemistry, University of Oviedo, E-33006, Oviedo, Spain
| | - Aurora Costales
- Department of Analytical and Physical Chemistry, University of Oviedo, E-33006, Oviedo, Spain
| | - Ángel Martín Pendás
- Department of Analytical and Physical Chemistry, University of Oviedo, E-33006, Oviedo, Spain
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12
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Transition-State Expansion: A Quantitative Model for Counterion Effects in Ionic Reactions. iScience 2020; 23:101593. [PMID: 33083752 PMCID: PMC7554029 DOI: 10.1016/j.isci.2020.101593] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 08/03/2020] [Accepted: 09/17/2020] [Indexed: 11/21/2022] Open
Abstract
Ionic reactions are the most common reactions used in chemical synthesis. In relatively low dielectric constant solvents (e.g., dichloromethane, toluene), ions usually exist as ion pairs. Despite the importance of counterions, a quantitative description of how the paired 'counterion' affects the reaction kinetic is still elusive. We introduce a general and quantitative model, namely transition-state expansion (TSE), that describes how the size of a counterion affects the transition-state structure and the kinetics of an ionic reaction. This model could rationalize the counterion effects in nucleophilic substitutions and gold-catalyzed enyne cycloisomerizations. A quantitative model for counterion effects was introduced 'Transition State Expansion' was used to describes how the size of a counterion affects the kinetics
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13
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Tang W, Zhao J, Jiang P, Xu X, Zhao S, Tong Z. Solvent Effects on the Symmetric and Asymmetric S N2 Reactions in the Acetonitrile Solution: A Reaction Density Functional Theory Study. J Phys Chem B 2020; 124:3114-3122. [PMID: 32208658 DOI: 10.1021/acs.jpcb.0c00607] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Bimolecular nucleophilic substitution (SN2) reactions are of great importance in chemistry and biochemistry due to their capability of constructing functional groups. In this work, we investigate the solvent effect on the free energy profiles of symmetric and asymmetric SN2 reactions in the acetonitrile solution using the proposed reaction density functional theory (RxDFT) method. This multiscale method utilizes quantum density functional theory for calculating intrinsic reaction free energy coupled with classical density functional theory for addressing solvation contribution. We find that the presence of acetonitrile brings both the polarization effect and solvation effect on the reaction pathways. For the eight selected symmetric SN2 reactions, the predicated reaction pathways agree well with the results from the direct and thermodynamic cycle (TC) methods with the SMD-M062X solvation model. In addition, the polarization effect reduces the free energy barriers by about 6 kcal/mol, while the solvation effect increases the barriers by about 18 kcal/mol. For the four selected asymmetric SN2 reactions, the predicted reaction pathways agree well with the results from the Monte Carlo simulations and experiments. The polarization effect and the solvation effect mutually reduce the free energy barriers, and the solvation effect plays a dominant role.
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Affiliation(s)
- Weiqiang Tang
- State Key Laboratory of Chemical Engineering and School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Jihao Zhao
- State Key Laboratory of Chemical Engineering and School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Peng Jiang
- State Key Laboratory of Chemical Engineering and School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China.,Key Laboratory for Green Chemical Process of Ministry of Education, School of Chemical Engineering & Pharmacy, Wuhan Institute of Technology, Wuhan 430073, China
| | - Xiaofei Xu
- State Key Laboratory of Chemical Engineering and School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Shuangliang Zhao
- State Key Laboratory of Chemical Engineering and School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China.,Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology and School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China
| | - Zhangfa Tong
- Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology and School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China
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14
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Bettens T, Alonso M, De Proft F, Hamlin TA, Bickelhaupt FM. Ambident Nucleophilic Substitution: Understanding Non-HSAB Behavior through Activation Strain and Conceptual DFT Analyses. Chemistry 2020; 26:3884-3893. [PMID: 31957943 PMCID: PMC7154642 DOI: 10.1002/chem.202000272] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Indexed: 01/31/2023]
Abstract
The ability to understand and predict ambident reactivity is key to the rational design of organic syntheses. An approach to understand trends in ambident reactivity is the hard and soft acids and bases (HSAB) principle. The recent controversy over the general validity of this principle prompted us to investigate the competing gas-phase SN 2 reaction channels of archetypal ambident nucleophiles CN- , OCN- , and SCN- with CH3 Cl (SN 2@C) and SiH3 Cl (SN 2@Si), using DFT calculations. Our combined analyses highlight the inability of the HSAB principle to correctly predict the reactivity trends of these simple, model reactions. Instead, we have successfully traced reactivity trends to the canonical orbital-interaction mechanism and the resulting nucleophile-substrate interaction energy. The HOMO-LUMO orbital interactions set the trend in both SN 2@C and SN 2@Si reactions. We provide simple rules for predicting the ambident reactivity of nucleophiles based on our Kohn-Sham molecular orbital analysis.
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Affiliation(s)
- Tom Bettens
- Eenheid Algemene Chemie (ALGC)Vrije Universiteit BrusselPleinlaan 21050BrusselsBelgium
| | - Mercedes Alonso
- Eenheid Algemene Chemie (ALGC)Vrije Universiteit BrusselPleinlaan 21050BrusselsBelgium
| | - Frank De Proft
- Eenheid Algemene Chemie (ALGC)Vrije Universiteit BrusselPleinlaan 21050BrusselsBelgium
| | - Trevor A. Hamlin
- Department of Theoretical ChemistryAmsterdam Institute of Molecular and Life Sciences (AIMMS)Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081HVAmsterdamThe Netherlands
| | - F. Matthias Bickelhaupt
- Department of Theoretical ChemistryAmsterdam Institute of Molecular and Life Sciences (AIMMS)Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081HVAmsterdamThe Netherlands
- Institute for Molecules and Materials (IMM)Radboud University NijmegenHeyendaalseweg 1356525AJNijmegenThe Netherlands
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15
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Tirado-Rives J, Jorgensen WL. QM/MM Calculations for the Cl - + CH 3Cl S N2 Reaction in Water Using CM5 Charges and Density Functional Theory. J Phys Chem A 2019; 123:5713-5717. [PMID: 31246023 DOI: 10.1021/acs.jpca.9b04121] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The prototypical SN2 reaction of chloride ion with methyl chloride has been reinvestigated in aqueous solution using QM/MM methodology featuring MO6-2X/6-31+G(d) calculations with the TIP4P water model, and partial charges were computed with the CM5 method. Though the DFT method yields excellent gas-phase energetics for the reaction, the QM/MM approach is found to yield overestimation of the activation barrier by ca. 12 kcal/mol. The discrepancy is traced to underestimate of the magnitude of the partial charges on the chlorine atoms in the transition structure. When CM1 or CM3 charges based on semiempirical wave functions are used instead, the agreement with experiment is much improved. The findings emphasize the sensitivity of the results of QM/MM calculations to the choice of QM method, the MM force field, and implementation of the QM/MM interface.
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Affiliation(s)
- Julian Tirado-Rives
- Department of Chemistry , Yale University , New Haven , Connecticut 06520-8107 , United States
| | - William L Jorgensen
- Department of Chemistry , Yale University , New Haven , Connecticut 06520-8107 , United States
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16
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Chen J, Shao Y, Ho J. Are Explicit Solvent Models More Accurate than Implicit Solvent Models? A Case Study on the Menschutkin Reaction. J Phys Chem A 2019; 123:5580-5589. [DOI: 10.1021/acs.jpca.9b03995] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Junbo Chen
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia
| | - Yihan Shao
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - Junming Ho
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia
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17
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Effect of solvent polarity on the potential energy surface in the SN2 reaction of F− + CH3Cl. COMPUT THEOR CHEM 2019. [DOI: 10.1016/j.comptc.2019.01.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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18
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Cai C, Tang W, Qiao C, Jiang P, Lu C, Zhao S, Liu H. A reaction density functional theory study of the solvent effect in prototype SN2 reactions in aqueous solution. Phys Chem Chem Phys 2019; 21:24876-24883. [DOI: 10.1039/c9cp03888d] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Reaction density functional theory (RxDFT), combining quantum DFT with classical DFT, has been employed to investigate the solvent effect and free energy profiles of SN2 reactions in aqueous solution.
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Affiliation(s)
- Cheng Cai
- State Key Laboratory of Chemical Engineering and School of Chemical Engineering, East China University of Science and Technology
- Shanghai
- China
- School of Chemistry and Molecular Engineering
- East China University of Science and Technology
| | - Weiqiang Tang
- State Key Laboratory of Chemical Engineering and School of Chemical Engineering, East China University of Science and Technology
- Shanghai
- China
| | - Chongzhi Qiao
- State Key Laboratory of Chemical Engineering and School of Chemical Engineering, East China University of Science and Technology
- Shanghai
- China
| | - Peng Jiang
- State Key Laboratory of Chemical Engineering and School of Chemical Engineering, East China University of Science and Technology
- Shanghai
- China
| | - Changjie Lu
- State Key Laboratory of Chemical Engineering and School of Chemical Engineering, East China University of Science and Technology
- Shanghai
- China
| | - Shuangliang Zhao
- State Key Laboratory of Chemical Engineering and School of Chemical Engineering, East China University of Science and Technology
- Shanghai
- China
| | - Honglai Liu
- School of Chemistry and Molecular Engineering
- East China University of Science and Technology
- Shanghai
- China
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19
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Hamlin TA, Swart M, Bickelhaupt FM. Nucleophilic Substitution (S N 2): Dependence on Nucleophile, Leaving Group, Central Atom, Substituents, and Solvent. Chemphyschem 2018; 19:1315-1330. [PMID: 29542853 PMCID: PMC6001448 DOI: 10.1002/cphc.201701363] [Citation(s) in RCA: 118] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Indexed: 11/12/2022]
Abstract
The reaction potential energy surface (PES), and thus the mechanism of bimolecular nucleophilic substitution (SN 2), depends profoundly on the nature of the nucleophile and leaving group, but also on the central, electrophilic atom, its substituents, as well as on the medium in which the reaction takes place. Here, we provide an overview of recent studies and demonstrate how changes in any one of the aforementioned factors affect the SN 2 mechanism. One of the most striking effects is the transition from a double-well to a single-well PES when the central atom is changed from a second-period (e. g. carbon) to a higher-period element (e.g, silicon, germanium). Variations in nucleophilicity, leaving group ability, and bulky substituents around a second-row element central atom can then be exploited to change the single-well PES back into a double-well. Reversely, these variations can also be used to produce a single-well PES for second-period elements, for example, a stable pentavalent carbon species.
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Affiliation(s)
- Trevor A. Hamlin
- Department of Theoretical Chemistry andAmsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081 HVAmsterdamThe Netherlands
| | - Marcel Swart
- Department of Theoretical Chemistry andAmsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081 HVAmsterdamThe Netherlands
- Institut de Química Computacional I Catàlisi and Department de QuímicaUniversitat de Girona17003GironaSpain
- ICREAPg. Lluís Companys 2308010BarcelonaSpain
| | - F. Matthias Bickelhaupt
- Department of Theoretical Chemistry andAmsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081 HVAmsterdamThe Netherlands
- Institute of Molecules and Materials (IMM)Radboud UniversityHeyendaalseweg 1356525 AJNijmegenThe Netherlands
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20
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Laloo JZA, Rhyman L, Larrañaga O, Ramasami P, Bickelhaupt FM, de Cózar A. Ion-Pair S N 2 Reaction of OH - and CH 3 Cl: Activation Strain Analyses of Counterion and Solvent Effects. Chem Asian J 2018; 13:1138-1147. [PMID: 29437289 DOI: 10.1002/asia.201800082] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 02/12/2018] [Indexed: 11/10/2022]
Abstract
We have theoretically studied the non-identity SN 2 reactions of Mn OH(n-1) +CH3 Cl (M+ =Li+ , Na+ , K+ , and MgCl+ ; n=0, 1) in the gas phase and in THF solution at the OLYP/6-31++G(d,p) level using polarizable continuum model (PCM) implicit solvation. We want to explore and understand the effect of the metal counterion M+ and solvation on the reaction profile and the stereoselectivity of these processes. To this end, we have explored the potential energy surfaces of the backside (SN 2-b) and frontside (SN 2-f) pathways. To explain the computed trends, we have carried out analyses with an extended activation strain model (ASM) of chemical reactivity that includes the treatment of solvation effects.
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Affiliation(s)
- Jalal Z A Laloo
- Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit, 80837, Mauritius
| | - Lydia Rhyman
- Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit, 80837, Mauritius.,Department of Applied Chemistry, University of Johannesburg, Doornfontein Campus, Johannesburg, 2028, South Africa
| | - Olatz Larrañaga
- Departamento de Química Orgánica I, Facultad de Química, Universidad del País Vasco (UPV/EHU) and Donostia International Physics Center (DIPC), P. K. 1072, 20018, San Sebastián-Donostia, Spain
| | - Ponnadurai Ramasami
- Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit, 80837, Mauritius.,Department of Applied Chemistry, University of Johannesburg, Doornfontein Campus, Johannesburg, 2028, South Africa
| | - F Matthias Bickelhaupt
- Department of Theoretical Chemistry, Amsterdam Center for Multiscale Modeling (ACMM), Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081, HV, Amsterdam, The Netherlands.,Institute of Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525, AJ, Nijmegen, The Netherlands
| | - Abel de Cózar
- Departamento de Química Orgánica I, Facultad de Química, Universidad del País Vasco (UPV/EHU) and Donostia International Physics Center (DIPC), P. K. 1072, 20018, San Sebastián-Donostia, Spain.,Department of Theoretical Chemistry, Amsterdam Center for Multiscale Modeling (ACMM), Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081, HV, Amsterdam, The Netherlands.,IKERBASQUE, Basque Foundation for Science, 48013, Bilbao, Spain
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21
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Microsolvation effects on the reactivity of oxy-nucleophiles: the case of gas-phase S N2 reactions of YO -(CH 3OH) n=1,2 towards CH 3Cl. J Mol Model 2017; 23:192. [PMID: 28528446 DOI: 10.1007/s00894-017-3351-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Accepted: 04/19/2017] [Indexed: 10/19/2022]
Abstract
The modified G4(MP2) method was applied to explore microsolvation effects on the reactivity of four solvated normal oxy-nucleophiles YO-(CH3OH) n=1,2 (Y = CH3, C2H5, FC2H4, ClC2H4), and five α-oxy-nucleophiles YO-(CH3OH) n=1,2 (Y = HO, CH3O, F, Cl, Br), in gas-phase SN2 reactions towards the substrate CH3Cl. Based on a Brønsted-type plot, our calculations reveal that the overall activation barriers of five microsolvated α-oxy-nucleophiles are obviously smaller than the prediction from the correlation line constructed by four normal microsolvated ones to different degrees, and clearly demonstrate the existence of an α-effect in the presence of one or two methanol molecule(s). Moreover, it was found that the α-effect of the mono-methanol microsolvated α-nucleophile is stronger than that of the monohydrated α-nucleophile. However, the α-effect of YO-(CH3OH)2 becomes weaker for Y = HO and CH3O, whereas it becomes stronger for Y = F, Cl, Br than that of YO-(H2O)2, which can be explained by analyses of the activation strain model in the two cases. It was also found that the rationale about the low ionization energy of α-nucleophile inducing the α-effect was not widely significant. Graphical abstract Variation of alpha-effect in the gas-phase SN2 reaction with the microsolvation.
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22
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Egorova KS, Gordeev EG, Ananikov VP. Biological Activity of Ionic Liquids and Their Application in Pharmaceutics and Medicine. Chem Rev 2017; 117:7132-7189. [PMID: 28125212 DOI: 10.1021/acs.chemrev.6b00562] [Citation(s) in RCA: 879] [Impact Index Per Article: 125.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Ionic liquids are remarkable chemical compounds, which find applications in many areas of modern science. Because of their highly tunable nature and exceptional properties, ionic liquids have become essential players in the fields of synthesis and catalysis, extraction, electrochemistry, analytics, biotechnology, etc. Apart from physical and chemical features of ionic liquids, their high biological activity has been attracting significant attention from biochemists, ecologists, and medical scientists. This Review is dedicated to biological activities of ionic liquids, with a special emphasis on their potential employment in pharmaceutics and medicine. The accumulated data on the biological activity of ionic liquids, including their antimicrobial and cytotoxic properties, are discussed in view of possible applications in drug synthesis and drug delivery systems. Dedicated attention is given to a novel active pharmaceutical ingredient-ionic liquid (API-IL) concept, which suggests using traditional drugs in the form of ionic liquid species. The main aim of this Review is to attract a broad audience of chemical, biological, and medical scientists to study advantages of ionic liquid pharmaceutics. Overall, the discussed data highlight the importance of the research direction defined as "Ioliomics", studies of ions in liquids in modern chemistry, biology, and medicine.
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Affiliation(s)
- Ksenia S Egorova
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences , Leninsky prospect 47, Moscow 119991, Russia
| | - Evgeniy G Gordeev
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences , Leninsky prospect 47, Moscow 119991, Russia
| | - Valentine P Ananikov
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences , Leninsky prospect 47, Moscow 119991, Russia.,Department of Chemistry, Saint Petersburg State University , Stary Petergof 198504, Russia
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23
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Uggerud E. The Factors Determining Reactivity in Nucleophilic Substitution. ADVANCES IN PHYSICAL ORGANIC CHEMISTRY 2017. [DOI: 10.1016/bs.apoc.2017.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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24
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Haddon RC, Tian Z, Jiang DE. Comparative Reaction Diagrams for the SN2 Reaction Formulated According to the Leffler Analysis and the Hammond Postulate. J Org Chem 2016; 81:3648-53. [DOI: 10.1021/acs.joc.6b00298] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Robert C. Haddon
- Chemistry Department and
Chemical Engineering Department, University of California, Riverside, California 92521, United States
| | - Ziqi Tian
- Chemistry Department and
Chemical Engineering Department, University of California, Riverside, California 92521, United States
| | - De-en Jiang
- Chemistry Department and
Chemical Engineering Department, University of California, Riverside, California 92521, United States
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25
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Laloo JZA, Rhyman L, Ramasami P, Bickelhaupt FM, de Cózar A. Ion-Pair SN 2 Substitution: Activation Strain Analyses of Counter-Ion and Solvent Effects. Chemistry 2016; 22:4431-9. [PMID: 26879231 DOI: 10.1002/chem.201504456] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Indexed: 12/20/2022]
Abstract
The ion-pair SN 2 reactions of model systems MnF(n-1) +CH3Cl(M(+) =Li(+), Na(+), K(+), and MgCl(+); n=0, 1) have been quantum chemically explored by using DFT at the OLYP/6-31++G(d,p) level. The purpose of this study is threefold: 1) to elucidate how the counterion M(+) modifies ion-pair SN 2 reactivity relative to the parent reaction F(-) +CH3Cl; 2) to determine how this influences stereochemical competition between the backside and frontside attacks; and 3) to examine the effect of solvation on these ion-pair SN2 pathways. Trends in reactivity are analyzed and explained by using the activation strain model (ASM) of chemical reactivity. The ASM has been extended to treat reactivity in solution. These findings contribute to a more rational design of tailor-made substitution reactions.
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Affiliation(s)
- Jalal Z A Laloo
- Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit, 80837, Mauritius
| | - Lydia Rhyman
- Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit, 80837, Mauritius
| | - Ponnadurai Ramasami
- Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit, 80837, Mauritius. .,Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh, 11451, Saudi Arabia.
| | - F Matthias Bickelhaupt
- Department of Theoretical Chemistry, Amsterdam Center for Multiscale Modeling (ACMM), Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV, Amsterdam, The Netherlands. .,Institute of Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands.
| | - Abel de Cózar
- Department of Theoretical Chemistry, Amsterdam Center for Multiscale Modeling (ACMM), Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV, Amsterdam, The Netherlands. .,Departamento de Química Orgánica I, Facultad de Química, Universidad del País Vasco P. K. 1072, 200880, San Sebastián-Donostia, Spain. .,IKERBASQUE, Basque Foundation for Science, 48013, Bilbao, Spain.
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26
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Abstract
We recently showed for a large data set of pKas and reduction potentials that free energies calculated directly within the SMD continuum model compares very well with corresponding thermodynamic cycle calculations in both aqueous and organic solvents [ Phys. Chem. Chem. Phys. 2015 , 17 , 2859 ]. In this paper, we significantly expand the scope of our study to examine the suitability of this approach for calculating general solution phase kinetics and thermodynamics, in conjunction with several commonly used solvation models (SMD-M062X, SMD-HF, CPCM-UAKS, and CPCM-UAHF) for a broad range of systems. This includes cluster-continuum schemes for pKa calculations as well as various neutral, radical, and ionic reactions such as enolization, cycloaddition, hydrogen and chlorine atom transfer, and SN2 and E2 reactions. On the basis of this benchmarking study, we conclude that the accuracies of both approaches are generally very similar-the mean errors for Gibbs free energy changes of neutral and ionic reactions are approximately 5 and 25 kJ mol(-1), respectively. In systems where there are significant structural changes due to solvation, as is the case for certain ionic transition states and amino acids, the direct approach generally afford free energy changes that are in better agreement with experiment.
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Affiliation(s)
- Junming Ho
- Agency for Science, Technology and Research, Institute of High Performance Computing , 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632.,Department of Chemistry, Yale University , P.O. Box 208107, New Haven, Connecticut 06520, United States
| | - Mehmed Z Ertem
- Chemistry Department, Brookhaven National Laboratory , Upton, New York 11973, United States
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27
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Ahmadi AA, Fattahi A. Influence of a β-OH substituent on SN2 reactions of fluoroethane: Intramolecular hydrogen bonding catalysis or inhibition? A theoretical study. COMPUT THEOR CHEM 2015. [DOI: 10.1016/j.comptc.2015.05.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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28
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Huang L, Wang W, Wei X, Wei H. New insights into hydrosilylation of unsaturated carbon-heteroatom (C═O, C═N) bonds by rhenium(V)-dioxo complexes. J Phys Chem A 2015; 119:3789-99. [PMID: 25827215 DOI: 10.1021/acs.jpca.5b00567] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The hydrosilylation of unsaturated carbon-heteroatom (C═O, C═N) bonds catalyzed by high-valent rhenium(V)-dioxo complex ReO2I(PPh3)2 (1) were studied computationally to determine the underlying mechanism. Our calculations revealed that the ionic outer-sphere pathway in which the organic substrate attacks the Si center in an η(1)-silane rhenium adduct to prompt the heterolytic cleavage of the Si-H bond is the most energetically favorable process for rhenium(V)-dioxo complex 1 catalyzed hydrosilylation of imines. The activation energy of the turnover-limiting step was calculated to be 22.8 kcal/mol with phenylmethanimine. This value is energetically more favorable than the [2 + 2] addition pathway by as much as 10.0 kcal/mol. Moreover, the ionic outer-sphere pathway competes with the [2 + 2] addition mechanism for rhenium(V)-dioxo complex 1 catalyzing the hydrosilylation of carbonyl compounds. Furthermore, the electron-donating group on the organic substrates would induce a better activity favoring the ionic outer-sphere mechanistic pathway. These findings highlight the unique features of high-valent transition-metal complexes as Lewis acids in activating the Si-H bond and catalyzing the reduction reactions.
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Affiliation(s)
- Liangfang Huang
- Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, Jiangsu Provincial Key Laboratory for NSLSCS, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210046, China
| | - Wenmin Wang
- Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, Jiangsu Provincial Key Laboratory for NSLSCS, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210046, China
| | - Xiaoqin Wei
- Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, Jiangsu Provincial Key Laboratory for NSLSCS, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210046, China
| | - Haiyan Wei
- Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, Jiangsu Provincial Key Laboratory for NSLSCS, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210046, China
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29
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Affiliation(s)
- Andrew J. Orr-Ewing
- School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom;
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30
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Orr-Ewing AJ. Perspective: Bimolecular chemical reaction dynamics in liquids. J Chem Phys 2014; 140:090901. [PMID: 24606343 DOI: 10.1063/1.4866761] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Bimolecular reactions in the gas phase exhibit rich and varied dynamical behaviour, but whether a profound knowledge of the mechanisms of isolated reactive collisions can usefully inform our understanding of reactions in liquid solutions remains an open question. The fluctuating environment in a liquid may significantly alter the motions of the reacting particles and the flow of energy into the reaction products after a transition state has been crossed. Recent experimental and computational studies of exothermic reactions of CN radicals with organic molecules indicate that many features of the gas-phase dynamics are retained in solution. However, observed differences may also provide information on the ways in which a solvent modifies fundamental chemical mechanisms. This perspective examines progress in the use of time-resolved infra-red spectroscopy to study reaction dynamics in liquids, discusses how existing theories can guide the interpretation of experimental data, and suggests future challenges for this field of research.
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Affiliation(s)
- Andrew J Orr-Ewing
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
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31
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Yang YF, Chung LW, Zhang X, Houk KN, Wu YD. Ligand-Controlled Reactivity, Selectivity, and Mechanism of Cationic Ruthenium-Catalyzed Hydrosilylations of Alkynes, Ketones, and Nitriles: A Theoretical Study. J Org Chem 2014; 79:8856-64. [DOI: 10.1021/jo501730n] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Yun-Fang Yang
- Lab
of Computational Chemistry and Drug Design, Laboratory of Chemical
Genomics, Peking University Shenzhen Graduate School, Shenzhen 518055, China
- Department
of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Lung Wa Chung
- Department
of Chemistry, South University of Science and Technology of China, Shenzhen 518055, China
| | - Xinhao Zhang
- Lab
of Computational Chemistry and Drug Design, Laboratory of Chemical
Genomics, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - K. N. Houk
- Department
of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Yun-Dong Wu
- Lab
of Computational Chemistry and Drug Design, Laboratory of Chemical
Genomics, Peking University Shenzhen Graduate School, Shenzhen 518055, China
- College
of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
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32
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Acevedo O, Jorgensen WL. Quantum and Molecular Mechanical (QM/MM) Monte Carlo Techniques for Modeling Condensed-Phase Reactions. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2014; 4:422-435. [PMID: 25431625 DOI: 10.1002/wcms.1180] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A recent review (Acc. Chem. Res. 2010, 43:142-151) examined our use and development of a combined quantum and molecular mechanical (QM/MM) technique for modelling organic and enzymatic reactions. Advances included the PDDG/PM3 semiempirical QM (SQM) method, computation of multi-dimensional potentials of mean force (PMF), incorporation of on-the-fly QM in Monte Carlo simulations, and a polynomial quadrature method for rapidly treating proton-transfer reactions. The current article serves as a follow up on our progress. Highlights include new reactions, alternative SQM methods, a polarizable OPLS force field, and novel solvent environments, e.g., "on water" and room temperature ionic liquids. The methodology is strikingly accurate across a wide range of condensed-phase and antibody-catalyzed reactions including substitution, decarboxylation, elimination, isomerization, and pericyclic classes. Comparisons are made to systems treated with continuum-based solvents and ab initio or density functional theory (DFT) methods. Overall, the QM/MM methodology provides detailed characterization of reaction paths, proper configurational sampling, several advantages over implicit solvent models, and a reasonable computational cost.
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Affiliation(s)
- Orlando Acevedo
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849
| | - Wiliiam L Jorgensen
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107
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33
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Rablen PR, McLarney BD, Karlow BJ, Schneider JE. How alkyl halide structure affects E2 and SN2 reaction barriers: E2 reactions are as sensitive as SN2 reactions. J Org Chem 2014; 79:867-79. [PMID: 24437451 DOI: 10.1021/jo4026644] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
High-level electronic structure calculations, including a continuum treatment of solvent, are employed to elucidate and quantify the effects of alkyl halide structure on the barriers of SN2 and E2 reactions. In cases where such comparisons are available, the results of these calculations show close agreement with solution experimental data. Structural factors investigated include α- and β-methylation, adjacency to unsaturated functionality (allyl, benzyl, propargyl, α to carbonyl), ring size, and α-halogenation and cyanation. While the influence of these factors on SN2 reactivity is mostly well-known, the present study attempts to provide a broad comparison of both SN2 and E2 reactivity across many cases using a single methodology, so as to quantify relative reactivity trends. Despite the fact that most organic chemistry textbooks say far more about how structure affects SN2 reactions than about how it affects E2 reactions, the latter are just as sensitive to structural variation as are the former. This sensitivity of E2 reactions to structure is often underappreciated.
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Affiliation(s)
- Paul R Rablen
- Department of Chemistry and Biochemistry, Swarthmore College , 500 College Avenue, Swarthmore, Pennsylvania 19081, United States
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34
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Klippenstein SJ, Pande VS, Truhlar DG. Chemical Kinetics and Mechanisms of Complex Systems: A Perspective on Recent Theoretical Advances. J Am Chem Soc 2014; 136:528-46. [DOI: 10.1021/ja408723a] [Citation(s) in RCA: 187] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Stephen J. Klippenstein
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Vijay S. Pande
- Department
of Chemistry and Structural Biology, Stanford University, Stanford, California 94305, United States
| | - Donald G. Truhlar
- Department
of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
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35
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Schmidt TC, Paasche A, Grebner C, Ansorg K, Becker J, Lee W, Engels B. QM/MM investigations of organic chemistry oriented questions. Top Curr Chem (Cham) 2014; 351:25-101. [PMID: 22392477 DOI: 10.1007/128_2011_309] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
About 35 years after its first suggestion, QM/MM became the standard theoretical approach to investigate enzymatic structures and processes. The success is due to the ability of QM/MM to provide an accurate atomistic picture of enzymes and related processes. This picture can even be turned into a movie if nuclei-dynamics is taken into account to describe enzymatic processes. In the field of organic chemistry, QM/MM methods are used to a much lesser extent although almost all relevant processes happen in condensed matter or are influenced by complicated interactions between substrate and catalyst. There is less importance for theoretical organic chemistry since the influence of nonpolar solvents is rather weak and the effect of polar solvents can often be accurately described by continuum approaches. Catalytic processes (homogeneous and heterogeneous) can often be reduced to truncated model systems, which are so small that pure quantum-mechanical approaches can be employed. However, since QM/MM becomes more and more efficient due to the success in software and hardware developments, it is more and more used in theoretical organic chemistry to study effects which result from the molecular nature of the environment. It is shown by many examples discussed in this review that the influence can be tremendous, even for nonpolar reactions. The importance of environmental effects in theoretical spectroscopy was already known. Due to its benefits, QM/MM can be expected to experience ongoing growth for the next decade.In the present chapter we give an overview of QM/MM developments and their importance in theoretical organic chemistry, and review applications which give impressions of the possibilities and the importance of the relevant effects. Since there is already a bunch of excellent reviews dealing with QM/MM, we will discuss fundamental ingredients and developments of QM/MM very briefly with a focus on very recent progress. For the applications we follow a similar strategy.
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Affiliation(s)
- Thomas C Schmidt
- Institut für Phys. und Theor. Chemie, Emil-Fischer-Strasse 42, Campus Hubland Nord, 97074, Würzburg, Germany
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36
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Kimura A, Kawauchi S, Yamamoto T, Tezuka Y. SN2 regioselectivity in the esterification of 5- and 7-membered azacycloalkane quaternary salts: a DFT study to reveal the transition state ring conformation prevailing over the ground state ring strain. Org Biomol Chem 2014; 12:6717-24. [DOI: 10.1039/c4ob00695j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
SN2 regioselectivity in 5- and 7-membered azacycloalkanes quaternary salts is directed by the transition state ring conformation.
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Affiliation(s)
- Akihiro Kimura
- Department of Organic and Polymeric Materials
- Tokyo Institute of Technology
- Tokyo, Japan
| | - Susumu Kawauchi
- Department of Organic and Polymeric Materials
- Tokyo Institute of Technology
- Tokyo, Japan
| | - Takuya Yamamoto
- Department of Organic and Polymeric Materials
- Tokyo Institute of Technology
- Tokyo, Japan
| | - Yasuyuki Tezuka
- Department of Organic and Polymeric Materials
- Tokyo Institute of Technology
- Tokyo, Japan
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37
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Parker VD, Li Z, Hao W. Is the Single-Transition-State Model Appropriate for the Fundamental Reactions of Organic Chemistry? Experimental Methods and Data Treatment, Pertinent Reactions, and Complementary Computational Studies. ADVANCES IN PHYSICAL ORGANIC CHEMISTRY 2014. [DOI: 10.1016/b978-0-12-800256-8.00001-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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38
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Mihaylov TT, Parac-Vogt TN, Pierloot K. A Mechanistic Study of the Spontaneous Hydrolysis of Glycylserine as the Simplest Model for Protein Self-Cleavage. Chemistry 2013; 20:456-66. [DOI: 10.1002/chem.201303564] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Indexed: 11/05/2022]
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39
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Thomsen DL, Reece JN, Nichols CM, Hammerum S, Bierbaum VM. Investigating the α-effect in gas-phase S(N)2 reactions of microsolvated anions. J Am Chem Soc 2013; 135:15508-14. [PMID: 24047410 DOI: 10.1021/ja4066943] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The α-effect-enhanced reactivity of nucleophiles with a lone-pair adjacent to the attacking center-was recently demonstrated for gas-phase S(N)2 reactions of HOO(-), supporting an intrinsic component of the α-effect. In the present work we explore the gas-phase reactivity of microsolvated nucleophiles in order to investigate in detail how the α-effect is influenced by solvent. We compare the gas-phase reactivity of the microsolvated α-nucleophile HOO(-)(H2O) to that of microsolvated normal alkoxy nucleophiles, RO(-)(H2O), in reaction with CH3Cl using a flowing afterglow-selected ion flow tube instrument. The results reveal enhanced reactivity of HOO(-)(H2O) and clearly demonstrate the presence of an α-effect for the microsolvated α-nucleophile. The association of the nucleophile with a single water molecule results in a larger Brønsted βnuc value than is the case for the unsolvated nucleophiles. Accordingly, the reactions of the microsolvated nucleophiles proceed through later transition states in which bond formation has progressed further. Calculations show a significant difference in solvent interaction for HOO(-) relative to the normal nucleophiles at the transition states, indicating that differential solvation may well contribute to the α-effect. The reactions of the microsolvated anions with CH3Cl can lead to formation of either the bare Cl(-) anion or the Cl(-)(H2O) cluster. The product distributions show preferential formation of the Cl(-) anion even though the formation of Cl(-)(H2O) would be favored thermodynamically. Although the structure of the HOO(-)(H2O) cluster resembles HO(-)(HOOH), we demonstrate that HOO(-) is the active nucleophile when the cluster reacts.
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Affiliation(s)
- Ditte L Thomsen
- Department of Chemistry, University of Copenhagen , Universitetsparken 5, Copenhagen, DK-2100 Denmark
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40
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Liang S, Roitberg AE. AM1 Specific Reaction Parameters for Reactions of Hydroxide Ion with Halomethanes in Complex Environments: Development and Testing. J Chem Theory Comput 2013; 9:4470-80. [DOI: 10.1021/ct400471m] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Shuai Liang
- Department of Chemistry and Quantum Theory Project, University of Florida, Gainesville, Florida 32611, United States
| | - Adrian E. Roitberg
- Department of Chemistry and Quantum Theory Project, University of Florida, Gainesville, Florida 32611, United States
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41
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Conner KM, Gronert S. Impact of alkyl substituents on the gas-phase competition between substitution and elimination. J Org Chem 2013; 78:8606-13. [PMID: 23895292 DOI: 10.1021/jo4013354] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The S(N)2 and E2 reactions of a series of alkyl bromides with varying substitution patterns at the α- and β-carbons have been studied in the gas phase using naphthoate and phenoxide-based nucleophiles. The experimental work is supported by calculations at the MP2/6-31+G(d,p)//MP2/6-31+G(d) level. The results parallel reactivity patterns observed in the condensed phase, but offer new insights into steric factors in S(N)2 processes. In the gas phase, polarizability is more important, and the highest S(N)2 reactivity is observed when the β-carbon is 2°. In addition, the data confirm that alkyl substituents at the β-carbon have a greater accelerating effect on E2 reactions than those at the α-carbon. Finally, computed data based on lowest enthalpy pathways provide poor descriptions of the reactions of the larger alkyl bromides and are skewed toward crowded systems that offer stabilizing, nonbonded interactions at the expense of conformational freedom.
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Affiliation(s)
- Keyanna M Conner
- Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284, USA
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42
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Swart M, Bickelhaupt FM. Benchmark study on the smallest bimolecular nucleophilic substitution reaction: H⁻+CH₄-->CH₄+H⁻. Molecules 2013; 18:7726-38. [PMID: 23823873 PMCID: PMC6270058 DOI: 10.3390/molecules18077726] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 06/03/2013] [Accepted: 06/28/2013] [Indexed: 11/16/2022] Open
Abstract
We report here a benchmark study on the bimolecular nucleophilic substitution (S(N)2) reaction between hydride and methane, for which we have obtained reference energies at the coupled cluster toward full configuration-interaction limit (CC-cf/CBS). Several wavefunction (HF, MP2, coupled cluster) and density functional methods are compared for their reliability regarding these reference data.
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Affiliation(s)
- Marcel Swart
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Pg. Lluís Companys 23, 08010 Barcelona, Spain
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, 17071 Girona, Spain
| | - F. Matthias Bickelhaupt
- Department of Theoretical Chemistry & Amsterdam Center for Multiscale Modeling, VU University, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands; E-Mail:
- Institute of Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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43
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LIANG JINXIA, WANG BINJU, CAO ZEXING. THE MECHANISM OF ACID-CATALYZED DECARBOXYLATION OF PYRROLE-2-CARBOXYLIC ACID: INSIGHTS FROM CLUSTER-CONTINUUM MODEL CALCULATIONS. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2013. [DOI: 10.1142/s021963361350017x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The decarboxylation of pyrrole-2-carboxylic acid comprises the addition of water to the carboxyl group and the C–C bond cleavage leading to the protonated carbonic acid. Herein possible concerted and stepwise mechanisms for the C-protonated and O-protonated pathways were extensively investigated by using the cluster-continuum model. The calculated results indicate that the initial hydration or the nucleophilic attack of water at the carbonyl group of both C- and O-protonated derivatives is the rate-determining step for the overall reaction, and the O-protonated pathway will dominate the whole reaction. The predicted activation Gibbs energies for the overall reaction initialized by the O-protonated species fall in the range of 83.3 ∼ 123.0 kJ/mol, showing good agreement with experimental values of 91.6 ∼ 101.3 kJ/mol. On the basis of extensive calculations, the remarkable dependence of the predicted mechanisms and thermodynamic values on the number of explicit water molecules in the cluster-continuum model was discussed.
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Affiliation(s)
- JINXIA LIANG
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial, Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 360015, P. R. China
| | - BINJU WANG
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial, Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 360015, P. R. China
| | - ZEXING CAO
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial, Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 360015, P. R. China
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44
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Otto R, Brox J, Trippel S, Stei M, Best T, Wester R. Exit Channel Dynamics in a Micro-Hydrated SN2 Reaction of the Hydroxyl Anion. J Phys Chem A 2013; 117:8139-44. [DOI: 10.1021/jp401347p] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- R. Otto
- Institut für
Ionenphysik
und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - J. Brox
- Physikalisches Institut, Universität Freiburg, Hermann-Herder-Straße
3, 79104 Freiburg, Germany
| | - S. Trippel
- Center for Free-Electron Laser
Science, DESY, Notke-Straße 85, 22706
Hamburg, Germany
| | - M. Stei
- Institut für
Ionenphysik
und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - T. Best
- Institut für
Ionenphysik
und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - R. Wester
- Institut für
Ionenphysik
und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
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45
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Doi K, Togano E, Xantheas SS, Nakanishi R, Nagata T, Ebata T, Inokuchi Y. Microhydration Effects on the Intermediates of the SN2 Reaction of Iodide Anion with Methyl Iodide. Angew Chem Int Ed Engl 2013; 52:4380-3. [DOI: 10.1002/anie.201207697] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Revised: 11/30/2012] [Indexed: 11/10/2022]
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46
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Doi K, Togano E, Xantheas SS, Nakanishi R, Nagata T, Ebata T, Inokuchi Y. Microhydration Effects on the Intermediates of the SN2 Reaction of Iodide Anion with Methyl Iodide. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201207697] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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47
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Kruse H, Goerigk L, Grimme S. Why the Standard B3LYP/6-31G* Model Chemistry Should Not Be Used in DFT Calculations of Molecular Thermochemistry: Understanding and Correcting the Problem. J Org Chem 2012; 77:10824-34. [DOI: 10.1021/jo302156p] [Citation(s) in RCA: 320] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Holger Kruse
- Theoretische Organische Chemie, Organisch-Chemisches Institut der Universität Münster, Corrensstrasse 40, D-48149 Münster, Germany
| | - Lars Goerigk
- School of Chemistry, The University of Sydney, Sydney, New South Wales 2006,
Australia
| | - Stefan Grimme
- Mulliken Center
for Theoretical
Chemistry, Institut für Physikalische und Theoretische Chemie der Universität Bonn, Beringstrasse 4,
D-53115 Bonn, Germany
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48
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Wang B, Cao Z. How water molecules modulate the hydration of CO2in water solution: Insight from the cluster-continuum model calculations. J Comput Chem 2012; 34:372-8. [DOI: 10.1002/jcc.23144] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Revised: 09/03/2012] [Accepted: 09/12/2012] [Indexed: 11/10/2022]
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49
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Matić M, Denegri B, Kronja O. Method for Estimating SN1 Rate Constants: Solvolytic Reactivity of Benzoates. J Org Chem 2012; 77:8986-98. [DOI: 10.1021/jo3013308] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Mirela Matić
- University of Zagreb, Faculty
of Pharmacy and Biochemistry, A. Kovačića 1, 10000 Zagreb,
Croatia
| | - Bernard Denegri
- University of Zagreb, Faculty
of Pharmacy and Biochemistry, A. Kovačića 1, 10000 Zagreb,
Croatia
| | - Olga Kronja
- University of Zagreb, Faculty
of Pharmacy and Biochemistry, A. Kovačića 1, 10000 Zagreb,
Croatia
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50
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Kretschmer R, Schlangen M, Kaupp M, Schwarz H. Neutral Metal Atoms Acting as a Leaving Group in Gas-Phase SN2 Reactions: M(CH3)+ + NH3 → CH3NH3+ + M (M = Zn, Cd, Hg). Organometallics 2012. [DOI: 10.1021/om300116c] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Robert Kretschmer
- Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni
135, 10623 Berlin
| | - Maria Schlangen
- Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni
135, 10623 Berlin
| | - Martin Kaupp
- Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni
135, 10623 Berlin
| | - Helmut Schwarz
- Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni
135, 10623 Berlin
- Chemistry Department, Faculty
of Science, King Abdulaziz University,
Jeddah 21589, Saudi Arabia
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