The microwave spectrum, force field and dipole moment of CF2

Kirchhoff, William H.; Lide, David R.; Powell, F. X.

doi:10.1016/0022-2852(73)90096-9

Cited by 71 publications

(25 citation statements)

References 15 publications

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“…11 It should be noted that these experimental values of r e and e are actually identical to the r av and av values of Kirchhoff et al 8 determined by microwave spectroscopy; they are probably the averaged values rather than the equilibrium values.…”

Section: Introductionsupporting

confidence: 64%

Simulation of Ã 1B1→X̃ 1A1 CF2 single vibronic level emissions: Including anharmonic and Duschinsky effects

Chau

Dyke

Lee

et al. 2001

The Journal of Chemical Physics

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CASSCF/MRCI/aug-cc-pVQZ͑no g͒ and RCCSD͑T͒/aug-cc-pVQZ potential energy functions were reported for the Ã 1 B 1 and X 1 A 1 states of CF 2 , respectively. Vibrational wave functions of the symmetric stretching and bending modes of the two states of CF 2 were obtained in variational calculations, employing Watson's Hamiltonian for a nonlinear molecule and anharmonic vibrational wave functions expressed as linear combinations of harmonic basis functions. Franck-Condon factors ͑FCFs͒ were computed for Ã 1 B 1 →X 1 A 1 CF 2 single vibronic level ͑SVL͒ emissions and the SVL emission spectra were simulated with the computed FCFs. When compared with the observed spectra, the simulated spectra obtained in the present investigation, which include allowance for anharmonicity and the Duschinsky effect, were found to be significantly superior to those reported previously, based on the harmonic oscillator model. Using the iterative Franck-Condon analysis procedure, with the geometry of the X 1 A 1 state fixed at the recently determined experimental equilibrium geometry, the geometry of the Ã 1 B 1 state of CF 2 , which gave the best match between simulated and observed spectra, was found to be r e (CF͒ϭ1.317 Å and e (FCF)ϭ121.25°.

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Section: Introductionsupporting

confidence: 64%

Simulation of Ã 1B1→X̃ 1A1 CF2 single vibronic level emissions: Including anharmonic and Duschinsky effects

Chau

Dyke

Lee

et al. 2001

The Journal of Chemical Physics

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“…It has been studied in some detail spectroscopically in the ultraviolet, [1][2][3][4] microwave [5,6] and infrared regions. [7][8][9][10] Structural parameters of the ground state, X 1 A 1 , and a number of excited states have been derived from electronic emission [4] and absorption spectroscopy, [2,3] and single vibronic level (SVL) fluorescence.…”

Section: Introductionmentioning

confidence: 99%

“…[1] Several microwave studies have been reported which provide precise rotational constants for the X 1 A 1 state. [5,6] Small reactive intermediates, such as CF 2 , play important roles in determining the etching rate, selectivity and anisotropy of plasma-etching processes. The mechanisms of CF 2 production and destruction in fluorocarbon reactive ionetching processes have been investigated using techniques such as laser induced fluorescence, [11] broad-band UV absorption spectroscopy, [12,13] infrared diode laser spectroscopy [14,15] and cavity-ring down spectroscopy.…”

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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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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“…The results of the literature (Jacox and Milligan, 1970) Dixon and Simon, 1970;al., 1979, 1982) Mathews, 1966Mathews, , 1967Powell and Lide, 1966;Kirchhoff and al., 1973;Bondybey, 1976, Ishiguro andHastie and al. 1969;Milligan and Jacox, 1967;Vaida, 1976;UY and al.…”

Section: Dihalogenocarbenes Bond Lengthmentioning

confidence: 99%

“…Bond lengths in Angstrom, degree, bond angle a = cc-pvtz Length bond in Angstrom, a= cc-pVTZ, b= (Balázs et Coll., 2000), g= al . , 1979, 1982 ;Mathews ,1966Mathews , ,1967Powell and Lide,1966 ;Kirchhoff and al., 1973 ;Bondybey, 1976 ;Ishiguro and al. , 1981 ) ,h= (Jacox and Milligan, 1970 ;al., 1979, 1982 ;Hastie and al.…”

Section: Dihalogenocarbenes Bond Lengthmentioning

confidence: 99%

Contribution of the study of the properties of carbenes with advanced quantum chemistry calculations: geometries

Alao¹,

Bede²

2012

AJSIR

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The purpose of this work is to determine the geometric parameters of methylene and six (6) analogues in the first electronic states: singlet state (S0) and triplet state (T1) with advanced quantum chemistry methods for a better knowledge of their structures. For this reason, we used Hartree-Fock (HF), MP2, B3LYP, G3, CBS -Q and CBS APNO levels of theory associated with correlated Dunning basis set (cc-pVTZ), using the Gaussian 03 suite of programs. According to this study, we observe that C -H bond lengths are always larger in the S0 state than in the T1 state for the methylene; according to the results of all computational methods used. For C -X (X = Cl) bond, we have the same behavior as for C -H bond in the methylene. When X = F, we have an opposite behavior. Indeed, C -X bond is always longer in the state T1 than in the state S0. Concerning bond angles, we observe that, the angle XCY is always smaller (100 ° -110°) in the S0 state than the T1 one (118° -135°). The valence angle increases from F to Cl; this may be explained both by the decrease of electronegativity and the steric hindrance of atoms becoming increasingly large. In the particular case of the monohydroxycarbene and dihydroxycarbene, we have a slightly more complex geometry than methylene and group of the halogenocarbenes because here, a dihedral angle is in addition to other internal drawcords.

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The microwave spectrum, force field and dipole moment of CF2

Cited by 71 publications

References 15 publications

Simulation of Ã 1B1→X̃ 1A1 CF2 single vibronic level emissions: Including anharmonic and Duschinsky effects

Simulation of Ã 1B1→X̃ 1A1 CF2 single vibronic level emissions: Including anharmonic and Duschinsky effects

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

Contribution of the study of the properties of carbenes with advanced quantum chemistry calculations: geometries

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The microwave spectrum, force field and dipole moment of CF2

Cited by 71 publications

References 15 publications

Simulation of Ã 1B1→X̃ 1A1 CF2 single vibronic level emissions: Including anharmonic and Duschinsky effects

Simulation of Ã 1B1→X̃ 1A1 CF2 single vibronic level emissions: Including anharmonic and Duschinsky effects

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

Contribution of the study of the properties of carbenes with advanced quantum chemistry calculations: geometries

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