The gas phase acidity of trifluoromethanesulphonic acid. An ab initio MO and density functional theory study

Otto, André; Steiger, Thomas; Schrader, Sigurd

doi:10.1016/s0022-2860(98)00389-5

Cited by 10 publications

(11 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The calculated potential function for triflic acid, HOSO 2 CF 3 (Figure , bottom curve), shows a minimum for gauche orientation with φ = 99.4° and a maximum for trans orientation that is 1.8 kcal mol -1 higher in energy. This result is in good agreement with earlier calculations that predict dihedral angles of φ = 110.4° (HF/3-21G*), 98.8° (HF/6-31G*), and 97.6° (MP2/6-31G**) . The HF/3-21G* method resulted in a barrier of 1.0 kcal mol -1 at φ = 180° .…”

Section: Discussionsupporting

confidence: 91%

“…Due to strong intermolecular hydrogen bonds, however, the conformation in the solid state may be different from that of the free acid. Various theoretical calculations for the isolated molecule predicted gauche orientation of the O−H bond with dihedral angles φ(H−O−S−C) between 110.4° (HF/3-21G*) and 97.6° (MP2/6-31G*) . In the present work we report a structure determination of methyl trifluoromethanesulfonate, CH 3 OSO 2 CF 3 (methyl triflate), applying GED and quantum chemical calculations.…”

Section: Introductionmentioning

confidence: 89%

See 1 more Smart Citation

Gas Phase Structure of Methyl Trifluoromethanesulfonate, CH₃OSO₂CF₃, and Conformational Properties of Covalent Sulfonates

et al. 1999

View full text Add to dashboard Cite

The molecular structure of methyl trifluoromethanesulfonate (CH3OSO2CF3, methyl triflate) was investigated by gas electron diffraction (GED) and quantumchemical calculations (HF/3-21G* and B3LYP/6-31G*). The GED analysis revealed a gauche conformation (methyl group gauche with respect to CF3 group) with a dihedral angle φ(C−O−S−C) = 89(7)°. This value is reproduced correctly by the calculations. Some calculated bond lengths and bond angles, however, differ from experimental values by up to ±0.07 Å and ±6°. Additional B3LYP/6-31G* calculations have been performed for some covalent sulfonates. The potential functions for internal rotation around the S−O single bond in FOSO2F and ClOSO2F possess minima for gauche and trans orientation of the O−X (X = F or Cl) bond. The trans minima are 1.6 and 1.3 kcal mol-1 higher in energy. The potential functions for triflic acid, HOSO2CF3, for CH3OSO2Cl and CH3OSO2F possess minima only for gauche structures and maxima for trans orientation. These results are in partial contrast to previous experimental studies.

show abstract

Section: Discussionsupporting

confidence: 91%

Section: Introductionmentioning

confidence: 89%

Gas Phase Structure of Methyl Trifluoromethanesulfonate, CH₃OSO₂CF₃, and Conformational Properties of Covalent Sulfonates

et al. 1999

View full text Add to dashboard Cite

show abstract

“…The applicability of the density functional theory (DFT) method in the present study to the systems of (CF 3 SO 3 /H/(H 2 O) 0–1 /CF 3 SO 3 ) − was verified as follows. Otto et al8 estimated the gas‐phase deprotonation enthalpy of CF 3 SO 3 H at 298 K by using the DFT method with DNP basis sets and B88‐LYP functionals (Becke 1988 exchange functional and Lee‐Yang‐Parr correlation functional). The estimated value, 298.2 kcal/mol, is in reasonable accord with the corresponding value9 of 299.8 kcal/mol from an ab initio molecular orbital theory method of the highest level, G2(MP2) (Gaussian‐2 method with Møller‐Plesset second order perturbation theory).…”

Section: Methodsmentioning

confidence: 99%

“…The estimated value, 298.2 kcal/mol, is in reasonable accord with the corresponding value9 of 299.8 kcal/mol from an ab initio molecular orbital theory method of the highest level, G2(MP2) (Gaussian‐2 method with Møller‐Plesset second order perturbation theory). We estimated the corresponding value, according to the standard procedure used in the above two previous studies,8, 9 by the DFT method in the present study. The obtained value was 299.8 kcal/mol, which shows good agreement with the above two calculated values.…”

Section: Methodsmentioning

confidence: 99%

Proton transfer in nafion membrane by quantum chemistry calculation

Tanimura

Matsuoka

2004

J Polym Sci B Polym Phys

View full text Add to dashboard Cite

We estimated the energy barriers of proton transfers in the systems of (CF3SO3/H/SO3CF3)− and (CF3SO3/H/H2O/SO3CF3)− as models of a water‐swollen Nafion membrane by an ab initio density functional quantum calculation method with consideration of the hydration effect. As a result, the proton transfer between the SO 3− sites, which is accompanied by one water molecule, was found to be one of the proton‐transfer mechanisms in the water‐swollen Nafion membrane; that is, the surface diffusion mechanism was found to be important for the proton transfer in that membrane. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 1905–1914, 2004

show abstract

“…Superacids play an important role in organic and inorganic chemistry. [1][2][3][4][5][6][7][8] However, there are only few reliable experimental 9,10 and theoretical [10][11][12][13][14] studies dealing with the estimation of their acidities in the gas phase.…”

Section: Introductionmentioning

confidence: 99%

The gas phase acidity of HBF4 (HF-BF3)

Otto¹

1999

PhysChemComm

View full text Add to dashboard Cite

The gas phase acidity of the complex superacid HBF 4 and the interaction of BF 3 with HF as well as the F¯ detachment from BF 4 have been calculated ab initio using high accuracy energy models [CBS-4, CBS-Q, CBS-QB3, G1, G2(MP2) and G2] as well as the density functional B3LYP formalism. All methods but CBS-4 and G1 provide practically equal acidity data for the gas phase and one may recommend 288-289 kcal mol -1 for the Gibbs free energy and 291-292 kcal mol -1 for the corresponding enthalpy at 298 K. The complex HF-BF 3 is unstable in vacuo as the Gibbs free energy of decomposition into HF and BF 3 is predicted to be between -3.6 and -4.6 kcal mol -1 depending on the method used. The conjugated base BF 4 ¯ is stable with respect to fluoride ion detachment. We recommend 81-82 kcal mol -1 and 72-73 kcal mol -1 for the enthalpy and the Gibbs free energy, respectively.

show abstract

The gas phase acidity of trifluoromethanesulphonic acid. An ab initio MO and density functional theory study

Cited by 10 publications

References 14 publications

Gas Phase Structure of Methyl Trifluoromethanesulfonate, CH₃OSO₂CF₃, and Conformational Properties of Covalent Sulfonates

Gas Phase Structure of Methyl Trifluoromethanesulfonate, CH₃OSO₂CF₃, and Conformational Properties of Covalent Sulfonates

Proton transfer in nafion membrane by quantum chemistry calculation

The gas phase acidity of HBF4 (HF-BF3)

Contact Info

Product

Resources

About

The gas phase acidity of trifluoromethanesulphonic acid. An ab initio MO and density functional theory study

Cited by 10 publications

References 14 publications

Gas Phase Structure of Methyl Trifluoromethanesulfonate, CH3OSO2CF3, and Conformational Properties of Covalent Sulfonates

Gas Phase Structure of Methyl Trifluoromethanesulfonate, CH3OSO2CF3, and Conformational Properties of Covalent Sulfonates

Proton transfer in nafion membrane by quantum chemistry calculation

The gas phase acidity of HBF4 (HF-BF3)

Contact Info

Product

Resources

About

Gas Phase Structure of Methyl Trifluoromethanesulfonate, CH₃OSO₂CF₃, and Conformational Properties of Covalent Sulfonates

Gas Phase Structure of Methyl Trifluoromethanesulfonate, CH₃OSO₂CF₃, and Conformational Properties of Covalent Sulfonates