Study of N–H, O–H, and S–H bond dissociation enthalpies and ionization potentials of substituted anilines, phenols, and thiophenols

Klein, Erik; Lukeš, Vladimı́r; Cibulková, Zuzana; Polovková, Júlia

doi:10.1016/j.theochem.2005.10.015

Cited by 69 publications

(56 citation statements)

References 39 publications

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“…B3LYP functional represent widely applied approach for the theoretical study of the reaction energetics. For mono-substituted phenols, thiophenols and anilines, it has been found that B3LYP functional provided the energetics of both the homolytic and heterolytic bond cleavage in very good accordance with available experimental and/or theoretical results (Klein et al 2006, Klein and Lukeš 2006a, 2006b, 2006c, Vagánek et al 2011, 2013, Najafi et al 2012). The pK a values of carboxylic acids calculated using the same functional are also in acceptable accordance with experiment (Charif et al 2007, Namazian et al 2004, Dissanayake and Senthilnithy 2009, Sastre et al 2013.…”

Section: Computational Detailssupporting

confidence: 64%

The DFT calculations of pK_a values of the cationic acids of aniline and pyridine derivatives in common solvents

Poliak

2014

Acta Chimica Slovaca

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Abstract:The theoretical pK a values of the derivatives of anilinium and pyridinium ions in 7 solvents are presented. For this purpose, the usage of isodesmic reaction scheme using the DFT/B3LYP approach with IEFPCM solvation was evaluated. We have shown that the suitable selection of reference species has the primary influence on the resulting data. For the studied anilinium ion derivatives the nonsubstituted anilinium ion seems to be a satisfactory reference system. The calculated values are in good accordance with the available experimental data with the RMS error of 1.00 and 0.99 pK a units in water and THF, respectively. The highest error in predicted pK a value is less than 2.0 pK a units in all cases. The chemical accuracy of the applied treatment is limited in the case of nitroaniline ions and the maximal therotetical uncertainty for derivatives of the pyridinium ion is within 2.1 pK a units. Our theoretical results enable us to predict the values of pK a for the solvents, where the experimental data are not completely available. Also the influence of the chemical structure on the accuracy of the applied method was discussed.

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Section: Computational Detailssupporting

confidence: 64%

The DFT calculations of pK_a values of the cationic acids of aniline and pyridine derivatives in common solvents

Poliak

2014

Acta Chimica Slovaca

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“…39,42,83,93 DiLabio et al 16,88,95 found that BDE and ΔBDE values of para-substituted phenols, 6-substituted-3-pyridinols, 2-substituted-5-pyrimidinols, and anilines are linearly dependent on Hammett constants σ p . Klein et al 37,48 found that BDE and ΔBDE values of para-substituted and meta-substituted phenols are linearly dependent on Hammett constants σ p and σ m .…”

Section: 36mentioning

confidence: 99%

“…In previous study show that B3LYP/6-311+G(2d,2p) method significantly underestimates vertical gas-phase ionization potentials obtained from E HOMO according to Koopmans' theorem for mono-substituted anilines, phenols and thiophenols. 93 However, the trends in ionization potentials, in terms of ΔIPs, are described reliably. Therefore, we decided to find expected linear dependence between calculated IPs and corresponding E HOMO values (Figure 4).…”

Section: 104mentioning

confidence: 99%

“…Knowledge of BDEs has been accumulating substantially for the past 15-20 years owing to the development of both experimental and quantum chemical techniques. 38,39,41,45,47,69,70,[82][83][84][85][86][87][88][89][90][91][92][93][94] In this study, all conformers have been optimized and the conformer with higher stability has been used in each case. The calculated BDE for the basic structure, Magnolol, in gas-phase reached 375 kJ mol .…”

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confidence: 99%

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DFT/B3LYP Study of the Substituent Effects on the Reaction Enthalpies of the Antioxidant Mechanisms of Magnolol Derivatives in the Gas-Phase and Water

Najafi¹,

Najafi²,

Najafi³

2012

Bulletin of the Korean Chemical Society

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In this paper, the study of various ortho-and meta-substituted Magnolol derivatives is presented. The reaction enthalpies related to three antioxidant action mechanisms HAT, SET-PT and SPLET for substituted Magnolols have been calculated using DFT/B3LYP method in gas-phase and water. Calculated results show that electronwithdrawing substituents increase the bond dissociation enthalpy (BDE), ionization potential (IP) and oxidation/ reduction enthalpy (O/RE), while electron-donating ones cause a rise in the proton dissociation enthalpy (PDE) and proton affinity (PA). In ortho-position, substituents show larger effect on reaction enthalpies than in metaposition. In comparison to gas-phase, water attenuates the substituent effect on all reaction enthalpies. In gasphase, BDEs are lower than PAs and IPs, i.e. HAT represents the thermodynamically preferred pathway. On the other hand, SPLET mechanism represents the thermodynamically favored process in water. Results show that calculated enthalpies can be successfully correlated with Hammett constants (σ m ) of the substituted Magnolols. Furthermore, calculated IP and PA values for substituted Magnolols show linear dependence on the energy of the highest occupied molecular orbital (E HOMO ).

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“…Therefore, it is a natural question how the energy gap between p-Y-C 6 H 4 S· ( ) and p-Y-C 6 H 4 S· ( ) will be changed as the electron donating or withdrawing Y group is substituted instead of H. Though the substitution effect on the S-H bond dissociation energy of thiophenols had been previously studied, [18][19][20][21][22][23] those studies were naturally focused only on the ground state of the thiophenoxyl radical.…”

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confidence: 99%

Chemical Substitution Effect on Energetic and Structural Differences between Ground and First Electronically Excited States of Thiophenoxyl Radicals

Yoon¹,

Lim²,

Woo³

et al. 2013

Bulletin of the Korean Chemical Society

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Effect of chemical substitution at the para-position of the thiophenoxyl radical has been theoretically investigated in terms of energetics, structures, charge densities and orbital shapes for the ground and first electronically excited states. It is found that the adiabatic energy gap increases when CH 3 or F is substituted at the para-position. This change is attributed to the stabilization of the ground state of thiophenoxyl radical through the electron-donating effect of F or CH 3 group as the charge or spin of the singly-occupied molecular orbital is delocalized over the entire molecule especially in the ground state whereas in the excited state it is rather localized on sulfur and little affected by chemical substitutions. Quantitative comparison of predictions based on four different quantum-mechanical calculation methods is presented.

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Study of N–H, O–H, and S–H bond dissociation enthalpies and ionization potentials of substituted anilines, phenols, and thiophenols

Cited by 69 publications

References 39 publications

The DFT calculations of pK_a values of the cationic acids of aniline and pyridine derivatives in common solvents

The DFT calculations of pK_a values of the cationic acids of aniline and pyridine derivatives in common solvents

DFT/B3LYP Study of the Substituent Effects on the Reaction Enthalpies of the Antioxidant Mechanisms of Magnolol Derivatives in the Gas-Phase and Water

Chemical Substitution Effect on Energetic and Structural Differences between Ground and First Electronically Excited States of Thiophenoxyl Radicals

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Study of N–H, O–H, and S–H bond dissociation enthalpies and ionization potentials of substituted anilines, phenols, and thiophenols

Cited by 69 publications

References 39 publications

The DFT calculations of pKa values of the cationic acids of aniline and pyridine derivatives in common solvents

The DFT calculations of pKa values of the cationic acids of aniline and pyridine derivatives in common solvents

DFT/B3LYP Study of the Substituent Effects on the Reaction Enthalpies of the Antioxidant Mechanisms of Magnolol Derivatives in the Gas-Phase and Water

Chemical Substitution Effect on Energetic and Structural Differences between Ground and First Electronically Excited States of Thiophenoxyl Radicals

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The DFT calculations of pK_a values of the cationic acids of aniline and pyridine derivatives in common solvents

The DFT calculations of pK_a values of the cationic acids of aniline and pyridine derivatives in common solvents