Ionization Energies, Appearance Energies, and Thermochemistry of CF2O and FCO

Buckley, Thomas J.; Johnson, Russell D.; Huie, Robert E.; Zhang, Z.; Kuo, Szu-Cherng; Klemm, R. B.

doi:10.1021/j100014a002

Cited by 59 publications

(75 citation statements)

References 14 publications

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“…Correction of zero point energies of the two states involved yields the best computed AIE 0 value of 11.46 AE 0.02 eV. This value agrees very well with the earlier experimental values of 11.445 AE 0.025 eV and 11.42 AE 0.01 eV obtained from photoionization mass spectrometry [19] and UV photoelectron spectroscopy, respectively [18] but less well with the AIE derived in this work of 11.362 eV. Figure 7 (middle spectrum).…”

supporting

confidence: 88%

“…From the assignment of the vibrational structure, values were obtained for the harmonic and fundamental frequencies of the symmetric stretching mode (n 1 ') and symmetric bending mode (n 2 ') in CF 2 + (X The first adiabatic ionization energy (AIE) of CF 2 is important in contributing to the determination of the enthalpy of ion-molecule reactions involving CF 2 + in plasmas. Previous determinations of the first AIE of CF 2 have included a study by vacuum ultraviolet photoelectron spectroscopy (PES), [18] which gave the first AIE as (11.42 AE 0.01) eV, a study with photoionization mass spectrometry (PIMS), [19] using radiation derived from a synchrotron source, which gave the first AIE as (11.445 AE 0.025) eV, and a study by electron impact mass spectrometry, which gave a value of (11.5 AE 0.4) eV. [20] The PES study [18] shows the first band of CF 2 to consist of regular structure, with at least fifteen components.…”

Section: Introductionmentioning

confidence: 99%

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Difluorocarbene Studied with Threshold Photoelectron Spectroscopy (TPES): Measurement of the First Adiabatic Ionization Energy (AIE) of CF₂

Innocenti¹,

Eypper²,

Lee³

et al. 2008

Chemistry A European J

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The first photoelectron band of difluorocarbene CF(2), has been studied by threshold photoelectron (TPE) spectroscopy. CF(2) was prepared by microwave discharge of a flowing mixture of hexafluoropropene, C(3)F(6), and argon. A vibrationally resolved band was observed in which at least twenty-two components were observed. In the first PE band of CF(2), the adiabatic ionization energy differs significantly from the vertical ionization energy because, for the ionization CF(2) (+) (X(2)A(1))+e(-) <-- CF(2) (X(1)A(1)), there is an increase in the FCF bond angle (by approximately 20 degrees ) and a decrease in the C--F bond length (by approximately 0.7 A). The adiabatic component was not observed in the experimental TPE spectrum. However, on comparing this spectrum with an ab initio/Franck-Condon simulation of this band, using results from high-level ab initio calculations, the structure associated with the vibrational components could be assigned. This led to alignment of the experimental TPE spectrum and the computed Franck-Condon envelope, and a determination of the first adiabatic ionization energy of CF(2) as (11.362+/-0.005) eV. From the assignment of the vibrational structure, values were obtained for the harmonic and fundamental frequencies of the symmetric stretching mode (nu(1)') and symmetric bending mode (nu(2)') in CF(2) (+) (X(2)A(1)).

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supporting

confidence: 88%

Section: Introductionmentioning

confidence: 99%

Difluorocarbene Studied with Threshold Photoelectron Spectroscopy (TPES): Measurement of the First Adiabatic Ionization Energy (AIE) of CF₂

Innocenti¹,

Eypper²,

Lee³

et al. 2008

Chemistry A European J

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“…In this paper we try to shed more light on the issue by applying photoionization mass spectrometry techniques, with the aim of finding additional support either for the theoretical ''high'' or experimental ''low'' value for ⌬H f°͑ CF 2 O͒. CF 2 O has been recently examined by photoionization by Buckley et al 19 However, these researchers were interested only in the threshold regions of the parent CF 2 O ϩ and fragment FCO ϩ ion, and they did not attempt to determine ⌬H f°͑ CF 2 O͒ independently. In fact, Buckley et al use the calculated ⌬H f°͑ CF 2 O͒ as a starting point to derive other thermodynamic quantities.…”

Section: Introductionmentioning

confidence: 99%

On the heat of formation of carbonyl fluoride, CF2O

Asher

Appelman

Ruščić

1996

The Journal of Chemical Physics

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In light of the recent controversy surrounding its heat of formation, CF 2 O was reexamined by photoionization mass spectrometry. In particular, the CO ϩ fragment ion yield curve from CF 2 O was interpreted in terms of a retarded CO ϩ ϩF 2 process, and a more facile two-step fragmentation to CO ϩ ϩ2F. The former process produces a weak, slowly growing tail region without a clear onset, while the latter occurs at higher energy and causes a pronounced growth with a conspicuous onset, which was found to occur at р20.87 ϩ0.03 / Ϫ0.07 eV at 0 K by fitting with a model curve that incorporates ''fluctuations'' associated with second-generation fragments. This onset leads to ⌬H f°298 ͑CF 2 O͒ у Ϫ149.1 ϩ1.4 / Ϫ0.7 kcal/mol, and indicates that the older experimental values for this quantity are too low by at least 3-4 kcal/mol. While the F 2 elimination is retarded by competition with lower energy processes, the two-step process derives its strength from the FCO ϩ fragment, which assumes the role of a pseudoparent. Thus, the onset of CO ϩ ϩ2F is expected to appear reasonably close to the thermochemical threshold. Such an interpretation indicates that recently calculated ab initio values of Ϫ145.3Ϯ1.7 kcal/mol and Ϫ145.6Ϯ1.0 kcal/mol are very likely too high by 3-4 kcal/mol. In addition, the adiabatic ionization potential of CF 2 O was refined to 13.024Ϯ0.004 eV, while the 0 K appearance potential of the FCO ϩ fragment was found by fitting to be р14.752Ϯ0.005 eV. Together with the suggested value for ⌬H f°( CF 2 O), these two onsets lead to ⌬H f°298 (CF 2 O ϩ ) ϭ 151.2 ϩ1.4 / Ϫ0.7 kcal/mol and ⌬H f°298 (FCO ϩ ) ϭ 173.5 ϩ1.4 / Ϫ0.7 kcal/mol.

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“…This prompted us to compare the interaction energies with the basic properties of the ketones. The proton affinities (PA) calculated at the B3LYP-D3/6-311++G(d,p) level as well as the calculated and experimental ionization potentials (IP) of the ketones [56][57][58][59][60][61] are reported in Table 4.…”

Section: Structures Of the Complexes And Interaction Energiesmentioning

confidence: 99%

On the nature of halogen bonded complexes between carbonyl bases and chlorotrifluoromethane

et al. 2015

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Ionization Energies, Appearance Energies, and Thermochemistry of CF2O and FCO

Cited by 59 publications

References 14 publications

Difluorocarbene Studied with Threshold Photoelectron Spectroscopy (TPES): Measurement of the First Adiabatic Ionization Energy (AIE) of CF₂

Difluorocarbene Studied with Threshold Photoelectron Spectroscopy (TPES): Measurement of the First Adiabatic Ionization Energy (AIE) of CF₂

On the heat of formation of carbonyl fluoride, CF2O

On the nature of halogen bonded complexes between carbonyl bases and chlorotrifluoromethane

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Ionization Energies, Appearance Energies, and Thermochemistry of CF2O and FCO

Cited by 59 publications

References 14 publications

Difluorocarbene Studied with Threshold Photoelectron Spectroscopy (TPES): Measurement of the First Adiabatic Ionization Energy (AIE) of CF2

Difluorocarbene Studied with Threshold Photoelectron Spectroscopy (TPES): Measurement of the First Adiabatic Ionization Energy (AIE) of CF2

On the heat of formation of carbonyl fluoride, CF2O

On the nature of halogen bonded complexes between carbonyl bases and chlorotrifluoromethane

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Product

Resources

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Difluorocarbene Studied with Threshold Photoelectron Spectroscopy (TPES): Measurement of the First Adiabatic Ionization Energy (AIE) of CF₂

Difluorocarbene Studied with Threshold Photoelectron Spectroscopy (TPES): Measurement of the First Adiabatic Ionization Energy (AIE) of CF₂