Assessment of <i>ab initio</i> MP2 and density functionals for characterizing the potential energy profiles of the S<sub>N</sub>2 reactions at N center

Yu, Feng

doi:10.1002/jcc.22963

Cited by 15 publications

(25 citation statements)

References 92 publications

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“…To the best of our knowledge, CAM‐B3LYP is not assessed as exhaustively as the other two functionals with respect to the energetics of reactions. In a recent study on nitrogen as a center of S N 2 reactions, the performance of the CAM‐B3LYP functional showed significant improvement in accuracy with respect to B3LYP: the mean unsigned error of the functional with the respective basis set was 2.5 kcal/mol . These results corroborate the improvement of CAM‐B3LYP with respect to the calculation of classical barrier heights reported in an earlier assessment of the CAM‐B3LYP functional …”

Section: Resultssupporting

confidence: 81%

Trapping acrylamide by a Michael addition: A computational study of the reaction between acrylamide and niacin

Papamokos

Dreyer

Navarini

et al. 2014

Int J of Quantum Chemistry

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Neurotoxic and carcinogenic acrylamide (ACR) is present in many food products. This finding spurred numerous studies for ACR scavengers. Niacin is putatively one of them because it reacts via Michael addition with ACR to form 1‐propanamide‐3‐carboxy pyridinium. Here, we study the mechanism and energetics of this reaction in aqueous solution by density functional theory. The CAM‐B3LYP and M06‐2X functionals with the 6‐31+G(d,p) basis set and implicit solvent were used. Single point calculations at the MP2 level with the same basis set were performed on optimized structures obtained at the M06‐2X level. Solvent effects comprehended both polarizable continuum model and solvation model density solvation models. The calculated NMR chemical shifts of 1‐propanamide‐3‐carboxy pyridinium are in agreement with experimental results. The theoretical study favors thermodynamically the formation of the adduct while the calculated activation energies turn out not to be too dissimilar from the ones measured for the alkylation reaction between ACR and 4(p‐nitrobenzyl)pyridine. © 2014 Wiley Periodicals, Inc.

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Section: Resultssupporting

confidence: 81%

Trapping acrylamide by a Michael addition: A computational study of the reaction between acrylamide and niacin

Papamokos

Dreyer

Navarini

et al. 2014

Int J of Quantum Chemistry

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“…19 Convergence tolerances of 10 À6 and 10 À4 hartree bohr À1 were used for the self-consistent field density and the gradient, respectively.…”

Section: Electronic Structure Calculationsmentioning

confidence: 99%

“…Most of these improvements are due to a deeper understanding of the role played by the exchange-correlation functional. [12][13][14][15][16][17][18][19][20] Although benchmark sets have contributed significantly to the construction of functionals with increasing applicability and with a minimum loss of accuracy, a fundamental outcome from several benchmark studies found in the literature is that most of the functionals are appropriate for particular sets of problems and systems. [5][6][7][8][9][10][11][12] Therefore, benchmark calculations are a crucial tool to assess the reliability of these functionals.…”

Section: Introductionmentioning

confidence: 99%

“…[2][3][4][5] Numerous attempts have been made to take into account exchange effects, electron correlation and kinetic energy corrections to formulations of the exchange-correlation functional. [17][18][19][20] An accurate description of reaction channels is important to predict chemical selectivity using, for instance, the Rice-Ramsperger-Kassel-Marcus (RRKM) and transition state (TS) theories. [12][13][14][15][16][17][18][19][20] Although benchmark sets have contributed significantly to the construction of functionals with increasing applicability and with a minimum loss of accuracy, a fundamental outcome from several benchmark studies found in the literature is that most of the functionals are appropriate for particular sets of problems and systems.…”

Section: Introductionmentioning

confidence: 99%

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Assessment of density-functionals for describing the X⁻+ CH₃ONO₂gas-phase reactions with X = F, OH, CH₂CN

Proenza

Souza

Ventura

et al. 2014

Phys. Chem. Chem. Phys.

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The energetics of the E CO 2, S N 2@C and S N 2@N channels of X À + CH 3 ONO 2 (X = F, OH, CH 2 CN) gas-phase reactions were computed using the CCSD(T)/CBS method. This benchmark extends a previous study with X = OH [M. A. F. de Souza et al., J. Am. Chem. Soc., 2012, 134, 19004] and was used to ascertain the accuracy and robustness of nineteen density-functionals for describing these potential energy profiles (PEP) as well as the kinetic product distributions obtained from RRKM calculations. Assessments were based on the mean unsigned error (MUE), the mean signed error (MSE), the #best : #worst (BW) criterion and the statistical confidence interval (CI) for the MSE. In general, double-hybrid (DH) functionals perform better than the range-separated ones, and both are better than the global-hybrid functionals. Based on the MUE and CI criteria the B2GPPLYP, B2PLYP, M08-SO, BMK, oB97X-D, CAM-B3LYP, M06, M08-HX, oB97X and B97-K functionals show the best performance in the description of these PEPs. Within this set, the B2GPPLYP functional is the most accurate and robust. The RRKM results indicate that the DHs are the best for describing the selectivities of these reactions. Compared to CCSD(T), the B2PLYP method has a relative error of only ca. 1% for the selectivity and the accuracy to provide the correct conclusion concerning the nonstatistical behavior of these reactions.Scheme 1 Reaction channels for the X À + CH 3 ONO 2 (X = F, 18 OH, CH 2 CN) systems with their experimental relative product distributions 28,30 and experimental DH 0 values 31 (in kcal mol À1 ).

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“…Recently, Yu carried out a detailed evaluation of the performance of MP2 and many DFT functionals for describing PESs of a wide range of nitrogen S N 2 reactions. 25 The dynamical information is more limited for the displacement at N. Ab initio trajectory calculations have been applied to study the F − + NH 2 F and OH − + NH 2 Y (Y = F and Cl) systems and the important nonstatistical behaviors have been suggested. 26 The F − + CH 3 Y → CH 3 F + Y − (Y = Cl and I) reactions are of particular interest since their PESs are substantially different than the conventional double-well model that characterizes gas phase S N 2 reactions at C center.…”

Section: Introductionmentioning

confidence: 99%

Theoretical Studies on F^– + NH₂Cl Reaction: Nucleophilic Substitution at Neutral Nitrogen

Liu

Zhang

et al. 2016

J. Phys. Chem. A

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The SN2 reactions at N center, denoted as SN2@N, has been recognized to play a significant role in carcinogenesis, although they are less studied and less understood. The potential energy profile for the model reaction of SN2@N, chloramine (NH2Cl) with fluorine anion (F(-)), has been characterized by extensive electronic structure calculations. The back-side SN2 channel dominates the reaction with the front-side SN2 channel becoming feasible at higher energies. The minimum energy pathway shows a resemblance to the well-known double-well potential model for SN2 reactions at carbon. However, the complexes involving nitrogen on both sides of the reaction barrier are characterized by NH---X (X = F or Cl) hydrogen bond and possess C1 symmetry, in contrast to the more symmetric ion-dipole carbon analogues. In the F(-) + NH2Cl system, the proton transfer pathway is found to become more competitive with the SN2 pathway than in the F(-) + CH3Cl system. The calculations reported here indicate that stationary point properties on the F(-) + NH2Cl potential energy surface are slightly perturbed by the theories employed. The MP2 and CAM-B3LYP, as well as M06-2X and MPW1K functionals give overall best agreement with the benchmark CCSD(T)/CBS energies for the major SN2 reaction channel, and are recommended as the preferred methods for the direct dynamics simulations to uncover the dynamic behaviors of the title reaction.

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Assessment of ab initio MP2 and density functionals for characterizing the potential energy profiles of the S_N2 reactions at N center

Cited by 15 publications

References 92 publications

Trapping acrylamide by a Michael addition: A computational study of the reaction between acrylamide and niacin

Trapping acrylamide by a Michael addition: A computational study of the reaction between acrylamide and niacin

Assessment of density-functionals for describing the X⁻+ CH₃ONO₂gas-phase reactions with X = F, OH, CH₂CN

Theoretical Studies on F^– + NH₂Cl Reaction: Nucleophilic Substitution at Neutral Nitrogen

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Assessment of ab initio MP2 and density functionals for characterizing the potential energy profiles of the SN2 reactions at N center

Cited by 15 publications

References 92 publications

Trapping acrylamide by a Michael addition: A computational study of the reaction between acrylamide and niacin

Trapping acrylamide by a Michael addition: A computational study of the reaction between acrylamide and niacin

Assessment of density-functionals for describing the X−+ CH3ONO2gas-phase reactions with X = F, OH, CH2CN

Theoretical Studies on F– + NH2Cl Reaction: Nucleophilic Substitution at Neutral Nitrogen

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Assessment of ab initio MP2 and density functionals for characterizing the potential energy profiles of the S_N2 reactions at N center

Assessment of density-functionals for describing the X⁻+ CH₃ONO₂gas-phase reactions with X = F, OH, CH₂CN

Theoretical Studies on F^– + NH₂Cl Reaction: Nucleophilic Substitution at Neutral Nitrogen