Ideal gas thermodynamic properties of propanone and 2-butanone

Chao, Jing; Zwolinski, Bruno J.

doi:10.1063/1.555535

Cited by 30 publications

(7 citation statements)

References 29 publications

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“…In Table , we see that entropy is significantly underestimated when only the low barrier methyl rotors are considered, in one case by more than 5 cal mol –1 K –1 , relative to the data in Stull. There is much better agreement to Stull for acetone, 2-butanone, and 2-pentanone when all of the rotors are considered where there are maximum absolute differences of 0.8 cal mol –1 K –1 for S ° 298 and 1.2 cal mol –1 K –1 for C p °( T ) between 300 and 1000 K. Similar agreement for 2-butanone to data from Chao is also observed.…”

Section: Resultssupporting

confidence: 70%

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Thermochemistry and Bond Dissociation Energies of Ketones

Hudzik

Bozzelli

2012

J. Phys. Chem. A

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Ketones are a major class of organic chemicals and solvents, which contribute to hydrocarbon sources in the atmosphere, and are important intermediates in the oxidation and combustion of hydrocarbons and biofuels. Their stability, thermochemical properties, and chemical kinetics are important to understanding their reaction paths and their role as intermediates in combustion processes and in atmospheric chemistry. In this study, enthalpies (ΔH°(f 298)), entropies (S°(T)), heat capacities (C(p)°(T)), and internal rotor potentials are reported for 2-butanone, 3-pentanone, 2-pentanone, 3-methyl-2-butanone, and 2-methyl-3-pentanone, and their radicals corresponding to loss of hydrogen atoms. A detailed evaluation of the carbon-hydrogen bond dissociation energies (C-H BDEs) is also performed for the parent ketones for the first time. Standard enthalpies of formation and bond energies are calculated at the B3LYP/6-31G(d,p), B3LYP/6-311G(2d,2p), CBS-QB3, and G3MP2B3 levels of theory using isodesmic reactions to minimize calculation errors. Structures, moments of inertia, vibrational frequencies, and internal rotor potentials are calculated at the B3LYP/6-31G(d,p) density functional level and are used to determine the entropies and heat capacities. The recommended ideal gas-phase ΔH°(f 298), from the average of the CBS-QB3 and G3MP2B3 levels of theory, as well as the calculated values for entropy and heat capacity are shown to compare well with the available experimental data for the parent ketones. Bond energies for primary, secondary, and tertiary radicals are determined; here, we find the C-H BDEs on carbons in the α position to the ketone group decrease significantly with increasing substitution on these α carbons. Group additivity and hydrogen-bond increment values for these ketone radicals are also determined.

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Section: Resultssupporting

confidence: 70%

“…In some cases, the work reactions utilized generated a ketone compound that is analyzed in this study. The reference Δ H ° f 298 values used in these cases are from literature values − shown in Table .…”

Section: Resultsmentioning

confidence: 99%

Thermochemistry and Bond Dissociation Energies of Ketones

Hudzik

Bozzelli

2012

J. Phys. Chem. A

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“…Table 9 also reveals that the standard deviations for each of the isodesmic reactions are of a similar magnitude to the pre- À57.02 AE 0.2/À56. 89 Chao and Zwolinski [46] /Cox and Pilcher [3] …”

Section: Isodesmic Reactionsmentioning

confidence: 99%

Thermodynamic and Ab Initio Analysis of the Controversial Enthalpy of Formation of Formaldehyde

et al. 2006

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There are two values, -26.0 and -27.7 kcal mol(-1), that are routinely reported in literature evaluations for the standard enthalpy of formation, Delta(f) H(o)(298), of formaldehyde (CH(2)=O), where error limits are less than the difference in values. In this study, we summarize the reported literature for formaldehyde enthalpy values based on evaluated measurements and on computational studies. Using experimental reaction enthalpies for a series of reactions involving formaldehyde, in conjunction with known enthalpies of formation, its enthalpy is determined to be -26.05+/-0.42 kcal mol(-1), which we believe is the most accurate enthalpy currently available. For the same reaction series, the reaction enthalpies are evaluated using six computational methods: CBS-Q, CBS-Q//B3, CBS-APNO, G2, G3, and G3B3 yield Delta(f) H(o)(298)=-25.90+/-1.17 kcal mol(-1), which is in good agreement to our experimentally derived result. Furthermore, the computational chemistry methods G3, G3MP2B3, CCSD/6-311+G(2df,p)//B3LYP/6-31G(d), CCSD(T)/6-311+G(2df,p)//B3LYP/6-31G(d), and CBS-APNO in conjunction with isodesmic and homodesmic reactions are used to determine Delta(f) H(o)(298). Results from a series of five work reactions at the higher levels of calculation are -26.30+/-0.39 kcal mol(-1) with G3, -26.45+/-0.38 kcal mol(-1) with G3MP2B3, -26.09+/-0.37 kcal mol(-1) with CBS-APNO, -26.19+/-0.48 kcal mol(-1) with CCSD, and -26.16+/-0.58 kcal mol(-1) with CCSD(T). Results from heat of atomization calculations using seven accurate ab initio methods yields an enthalpy value of -26.82+/-0.99 kcal mol(-1). The results using isodesmic reactions are found to give enthalpies more accurate than both other computational approaches and are of similar accuracy to atomization enthalpy calculations derived from computationally intensive W1 and CBS-APNO methods. Overall, our most accurate calculations provide an enthalpy of formation in the range of -26.2 to -26.7 kcal mol(-1), which is within computational error of the suggested experimental value. The relative merits of each of the three computational methods are discussed and depend upon the accuracy of experimental enthalpies of formation required in the calculations and the importance of systematic computational errors in the work reaction. Our results also calculate Delta(f) H(o)(298) for the formyl anion (HCO(-)) as 1.28+/-0.43 kcal mol(-1).

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“…In this Article, we extend this investigation of fluorinated molecules to the study of 1,1,1-trifluoro-2-butanone (TFB) for comparison with 2-butanone. The thermodynamic and spectroscopic properties of 2-butanone have been extensively studied. − The microwave spectrum was used to identify the lowest energy conformer and to derive the barriers to internal rotation of the two methyl groups. To the best of our knowledge, there is no comparable microwave study of TFB.…”

Section: Introductionmentioning

confidence: 99%

“…The thermodynamic and spectroscopic properties of 2-butanone have been extensively studied. [14][15][16][17][18] The microwave spectrum was used to identify the lowest energy conformer and to derive the barriers to internal rotation of the two methyl groups. To the best of our knowledge, there is no comparable microwave study of TFB.…”

Section: ' Introductionmentioning

confidence: 99%

Rotational Spectrum of 1,1,1-Trifluoro-2-butanone Using Chirped-Pulse Fourier Transform Microwave Spectroscopy

2011

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The pure rotational spectra of 1,1,1-trifluoro-2-butanone and its four (13)C isotopologues have been studied using the new chirped-pulsed Fourier transform microwave spectrometer at the University of Manitoba in combination with a conventional Balle-Flygare-type instrument. Quantum chemical calculations, at the MP2/6-311++G(d,p) level, were carried out to obtain information about the structure, relative stability, and difference in populations of the three lowest energy conformers corresponding to dihedral angles of 0°, 82.8°, and 119.2° along the carbon backbone. The observed spectra are that of conformer I (dihedral angle 0°), and, based on analysis of the observed splitting, the V(3) barrier to internal rotation of the methyl group has been determined to be 9.380(5) kJ mol(-1). The spectroscopic constants of the five isotopologues were used to precisely derive the r(s) and partial r(0) geometries of this conformer based on an assumed planar carbon backbone (as supported by the spectra and ab initio calculations).

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Ideal gas thermodynamic properties of propanone and 2-butanone

Cited by 30 publications

References 29 publications

Thermochemistry and Bond Dissociation Energies of Ketones

Thermochemistry and Bond Dissociation Energies of Ketones

Thermodynamic and Ab Initio Analysis of the Controversial Enthalpy of Formation of Formaldehyde

Rotational Spectrum of 1,1,1-Trifluoro-2-butanone Using Chirped-Pulse Fourier Transform Microwave Spectroscopy

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