Solvent Effects on n → σ* Transitions; Complex Formation Between Amines and Halomethanes

Stevenson, D. P.; Coppinger, Galvin M.

doi:10.1021/ja00861a004

Cited by 122 publications

(33 citation statements)

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“…[46][47][48] Substituted benzyl dimethylamines (48 and 49) were prepared by methylation of the corresponding benzyl chlorides by using the procedure recommended by Lee and Srinivasan. [49] Some amines react with CCl 4 [50,51] and were therefore analysed in C 2 Cl 4 . The differences between the data obtained in the two solvents are small [16] and no correction was attempted to scale the values obtained in tetrachloroethylene.…”

Section: Methodsmentioning

confidence: 99%

A Theoretical Evaluation of the pK_HBand Δ$H{{{\,\ominus}\hfill \atop {\rm HB}\hfill}}}$ Hydrogen‐Bond Scales of Nitrogen Bases

Besseau

Graton

Berthelot

2008

Chemistry A European J

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The experimental pKHB hydrogen-bond (HB) basicity scale and the corresponding DeltaH[symbol: see text]HB enthalpic scale of nitrogen compounds are extended and analysed in light of simple theoretical descriptors using the B3LYP density functional method and a medium-size basis set (6-31+G(d,p)).The selected training set includes 59 monofunctional unhindered nitrogen bases for which homogeneous and accurate experimental pKHB and DeltaH[symbol: see text]HB data have been determined by means of the association equilibrium of the bases with a reference hydrogen-bond acid, 4-fluorophenol, in CCl4. The three hybridisation states encountered in the nitrogen atom, sp, sp2 and sp3, are equally represented in this data set. A proper estimation of their experimental enthalpy (DeltaH[symbol: see text]HB) is directly attainable from the theoretical enthalpy of the complexation reaction with hydrogen fluoride (DeltaH[symbol: see text](HF)). However, a second parameter is required to calculate with good accuracy the experimental free energy of association represented by pKHB. About 99% of the variance of the pKHB scale is described by a bilinear equation using the minimum electrostatic potential (Vs,min) of the monomer in addition to the interaction energy (D0(HF). The equations are tested for an external set of 99 additional compounds including very different nitrogen bases such as ortho-substituted pyridines, polyazines and azoles.Theoretical calculations give a reliable estimation of hydrogen-bond basicity provided that the populations of the different isomers of the bases are taken into account by using the Boltzmann law, and that a specific halogen-bond interaction with the solvent CCl4 is considered for polybasic molecules.The pKHB scale can thus be extended to important classes of species experimentally inaccessible in CCl4, to polynitrogen compounds and to molecules of biological significance.

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Section: Methodsmentioning

confidence: 99%

A Theoretical Evaluation of the pK_HBand Δ$H{{{\,\ominus}\hfill \atop {\rm HB}\hfill}}}$ Hydrogen‐Bond Scales of Nitrogen Bases

Besseau

Graton

Berthelot

2008

Chemistry A European J

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“…The calculated partial molar volumes at infinite dilution and the partial molar excess volumes at infinite dilution can be presented mathematically as in equations (11) and (12). Calculated values are presented in tables 4 and 5 …”

Section: Resultsmentioning

confidence: 99%

Volumetric properties of dichloromethane with aniline or nitrobenzene at different temperatures: A theoretical and experimental study

Wang

2009

The Journal of Chemical Thermodynamics

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“…7-1 1). The nature of these solvent effects has been investigated in the case of halogenated solvents by a number of different methods and various types of interactions, contact pair formation, charge transfer, 'electrostatic' interactions have been invoked (12)(13)(14)(15).…”

Section: Discussionmentioning

confidence: 99%

'Breaking' and formation of hydrogen bonds by proton donor anesthetics

Massuda¹,

Sándorfy²

1977

Can. J. Chem.

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It has been shown previously that halofluorocarbons having anesthetic potency hinder the formation of hydrogen bonds (HB) of the [Formula: see text] types and it has been suggested that this is linked to a competitive mechanism involving another type of association. Since some of the most potent and widely used fluorocarbon anesthetics contain a mobile hydrogen atom the question arises if in such molecules the competitive mechanism involves the formation of HB's with the anesthetic as the proton donor instead of, or in addition to, association due to the electron acceptor properties of the higher halogens as seems to be the case for those fluorocarbon anesthetics which contain no hydrogen. Chloroform, halothane, methoxyflurane, enflurane, and 4,5-dichloro-2,2-difluoro-l,3-dioxolane have been studied from this point of view with the result that both mechanisms appear to operate.

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**Solvent Effects on n → σ^* Transitions; Complex Formation Between Amines and Halomethanes**

Cited by 122 publications

References 0 publications

A Theoretical Evaluation of the pK_HBand Δ$H{{{\,\ominus}\hfill \atop {\rm HB}\hfill}}}$ Hydrogen‐Bond Scales of Nitrogen Bases

A Theoretical Evaluation of the pK_HBand Δ$H{{{\,\ominus}\hfill \atop {\rm HB}\hfill}}}$ Hydrogen‐Bond Scales of Nitrogen Bases

Volumetric properties of dichloromethane with aniline or nitrobenzene at different temperatures: A theoretical and experimental study

'Breaking' and formation of hydrogen bonds by proton donor anesthetics

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Solvent Effects on n → σ* Transitions; Complex Formation Between Amines and Halomethanes

Cited by 122 publications

References 0 publications

A Theoretical Evaluation of the pKHBand Δ$H{{{\,\ominus}\hfill \atop {\rm HB}\hfill}}}$ Hydrogen‐Bond Scales of Nitrogen Bases

A Theoretical Evaluation of the pKHBand Δ$H{{{\,\ominus}\hfill \atop {\rm HB}\hfill}}}$ Hydrogen‐Bond Scales of Nitrogen Bases

Volumetric properties of dichloromethane with aniline or nitrobenzene at different temperatures: A theoretical and experimental study

'Breaking' and formation of hydrogen bonds by proton donor anesthetics

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Product

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**Solvent Effects on n → σ^* Transitions; Complex Formation Between Amines and Halomethanes**

A Theoretical Evaluation of the pK_HBand Δ$H{{{\,\ominus}\hfill \atop {\rm HB}\hfill}}}$ Hydrogen‐Bond Scales of Nitrogen Bases

A Theoretical Evaluation of the pK_HBand Δ$H{{{\,\ominus}\hfill \atop {\rm HB}\hfill}}}$ Hydrogen‐Bond Scales of Nitrogen Bases