Reactivity of hydrogen abstraction in CH2Cl2 by CHX− (X=F, Cl, Br, I) from a theoretical viewpoint

Junxi, Liang; Geng, Zhi‐Yuan; Wang, Yongcheng

doi:10.1016/j.theochem.2010.07.024

Cited by 6 publications

(2 citation statements)

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“…Note that in the Villano et al's experimental study (reactions of ClO − + RCl), the mechanism of deprotonation was not discussed, to the best of our knowledge. Consequently, based on our previous analogous investigations, [18][19][20] this study also examines the process ClO − + CHCl 3 ¡ ClOH + − CCl 3 , a deprotonation reaction. More important, periodic trends in the properties of interest can often be more important than absolute values.…”

Section: Introductionmentioning

confidence: 99%

Gas-phase reaction of ClO⁻with CH_nCl_4-_n(n= 0, 1, 2, 3) and CX₃H (X = F, Cl and Br): Substituent effect from a comparative study

et al. 2014

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Substituent effects on reactivity are studied using the hybrid B3LYP and BHandHLYP methods of density functional theory with the aug-cc-pVDZ basis set. The chosen testing models includes two very representative reactions in chemical research, the bimolecular nucleophilic substitution (S N 2) reaction and the deprotonation reaction, in which the former is represented by ClO − + CH n Cl 4-n (n = 0, 1, 2, 3), and the latter is based on reactions of ClO − with CX 3 H (X = F, Cl, and Br). Our theoretical findings suggest that a heavier substituent X in substrate results in a higher activation energy, a slower S N 2 reaction, but a faster deprotonation reaction. Those are well confirmed by some presented results from bond orders, second-order perturbative energy E (2) , and activation strain model analysis. Moreover, we have further explored the reactivity difference derived from substituent effects in term of the relationships of reactive barrier with the charges transferred and the leavingbond distance in TSs, respectively, especially the TSs in S N 2 reactions. Again, the rate constants at 298-1000 K are also evaluated for the S N 2 reactions presented through the transition state theory.Key words: anion ClO − , substituent effect, density functional theory (DFT).Résumé : L'effet des substituants sur la réactivité a été étudié par l'intermédiaire des fonctionnelles hybrides B3LYP et BHandHLYP de la théorie de la fonctionnelle de la densité, en utilisant la base aug-cc-pVDZ. Le modèle d'étude choisi comprend deux réactions très représentatives en chimie, la substitution nucléophile bimoléculaire (S N 2) et la réaction de déprotonation, qui sont respectivement représentées par la réaction ClO − + CH n Cl 4-n (n = 0, 1, 2, 3) et par la réaction de l'anion ClO − avec CX 3 H (X = F, Cl, et Br). Nos résultats théoriques indiquent que, plus la masse du substituant X du substrat est élevée, plus l'énergie d'activation est élevée, et donc, plus la réaction S N 2 est lente, mais plus la réaction de déprotonation est rapide. Ces résultats ont été largement confirmés par des résultats publiés portant sur les indices de liaison, l'énergie de perturbation de second ordre E (2) , et les calculs de barrière énergétique d'activation. En outre, nous avons exploré les différences de réactivité découlant de l'effet des substituants en fonction de la relation entre la barrière énergétique et les charges transférées ou la longueur du lien partant dans les états de transition, respectivement, et particulièrement dans les états de transition des réactions S N 2. Les constantes de vitesse aux températures allant de 298 à 1000 K ont aussi été calculées pour les réactions S N 2 à l'étude, selon la théorie de l'état de transition. [Traduit par la Rédaction] Mots-clés : anion ClO − , effet des substituants, théories de la fonctionnelle de la densité.

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Section: Introductionmentioning

confidence: 99%

Gas-phase reaction of ClO⁻with CH_nCl_4-_n(n= 0, 1, 2, 3) and CX₃H (X = F, Cl and Br): Substituent effect from a comparative study

et al. 2014

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“…Among many reaction mechanisms induced by radical anions CXY •− (X, Y = halogen), the HAT pattern attracts our great interest. Recently, we conducted many investigations on H‐abstraction reactions with CXY •− based on the reaction models CH 2 Cl 2 + CHX •− (X = halogen), CCl 3 H + CX 1 X 2•– (X 1 X 2 = HF, HCl, HBr, HI, FF, ClCl, BrBr, or II), and CHCl •– /CCl 2 •– + CX 3 H (X = halogen) . We found that the efficiency of H‐abstraction reactions increases when the substituent is changed from F to I, and when the anion CHX •– has activity higher than that of CX 2 •– .…”

Section: Introductionmentioning

confidence: 99%

Understanding halogen‐substituent assistance in H‐atom abstraction‐based reactions of CHCl^•− with CH_4 − nX_n (X = H, F, Cl; n = 0–3)

Junxi

Zhang³

et al. 2014

J of Physical Organic Chem

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The effect of halogen‐substituent on hydrogen abstraction mechanisms was studied by applying density functional theory functional calculations to the gas‐phase reactions between CHCl•− and CH4 − nXn (X = H, F, Cl; n = 0–3), and it is found that a heavier X substituent in the substrate results in a greater stabilization of corresponding complex, a lower activation energy, a faster H‐abstraction reaction, and greater exothermicity. However, CH4– reaction is more reactive than CH3F– reaction under the same condition because of dominant π‐donation from the electronegative F atom. We also explored the reactivity difference for the seven reactions in terms of factors derived from bond order, second‐order perturbative energy, and activation strain model analysis. The rate constants are evaluated over a wide temperature range of 298–1000 K by the conventional transition state theory. Copyright © 2014 John Wiley & Sons, Ltd.

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Substituent effects on the compounds CX1X2•− (X1, X2 = H, F, Cl, Br, I) from theoretical investigation

et al. 2012

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Reactivity of hydrogen abstraction in CH2Cl2 by CHX− (X=F, Cl, Br, I) from a theoretical viewpoint

Cited by 6 publications

References 42 publications

Gas-phase reaction of ClO⁻with CH_nCl_4-_n(n= 0, 1, 2, 3) and CX₃H (X = F, Cl and Br): Substituent effect from a comparative study

Gas-phase reaction of ClO⁻with CH_nCl_4-_n(n= 0, 1, 2, 3) and CX₃H (X = F, Cl and Br): Substituent effect from a comparative study

Understanding halogen‐substituent assistance in H‐atom abstraction‐based reactions of CHCl^•− with CH_4 − nX_n (X = H, F, Cl; n = 0–3)

Substituent effects on the compounds CX1X2•− (X1, X2 = H, F, Cl, Br, I) from theoretical investigation

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Reactivity of hydrogen abstraction in CH2Cl2 by CHX− (X=F, Cl, Br, I) from a theoretical viewpoint

Cited by 6 publications

References 42 publications

Gas-phase reaction of ClO−with CHnCl4-n(n= 0, 1, 2, 3) and CX3H (X = F, Cl and Br): Substituent effect from a comparative study

Gas-phase reaction of ClO−with CHnCl4-n(n= 0, 1, 2, 3) and CX3H (X = F, Cl and Br): Substituent effect from a comparative study

Understanding halogen‐substituent assistance in H‐atom abstraction‐based reactions of CHCl•− with CH4 − nXn (X = H, F, Cl; n = 0–3)

Substituent effects on the compounds CX1X2•− (X1, X2 = H, F, Cl, Br, I) from theoretical investigation

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Gas-phase reaction of ClO⁻with CH_nCl_4-_n(n= 0, 1, 2, 3) and CX₃H (X = F, Cl and Br): Substituent effect from a comparative study

Gas-phase reaction of ClO⁻with CH_nCl_4-_n(n= 0, 1, 2, 3) and CX₃H (X = F, Cl and Br): Substituent effect from a comparative study

Understanding halogen‐substituent assistance in H‐atom abstraction‐based reactions of CHCl^•− with CH_4 − nX_n (X = H, F, Cl; n = 0–3)