Fluoromethylidyne

Formula: CF
Molecular weight: 31.0091
IUPAC Standard InChI: InChI=1S/CF/c1-2
IUPAC Standard InChIKey: ISOSXCFSIDVNNC-UHFFFAOYSA-N
CAS Registry Number: 3889-75-6
Chemical structure:
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Reaction thermochemistry data

Go To: Top, Constants of diatomic molecules, References, Notes

Data compiled by: John E. Bartmess

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Individual Reactions

(CF₂^- • 4294967295 Fluoromethylidyne ) + = CF₂^-

By formula: (CF₂^- • 4294967295CF) + CF = CF₂^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	51.2 ± 2.3	kcal/mol	N/A	Schwartz, Davico, et al., 1999	gas phase; Neutral carbene triplet 54±3 kcal/mol above singlet
Δ_rH°	46.6 ± 3.6	kcal/mol	Ther	Murray, Leopold, et al., 1988	gas phase; Singlet-triplet splitting in neutral > 50 kcal/mol

(CAS Reg. No. 226407-20-1 • 4294967295 Fluoromethylidyne ) + = CAS Reg. No. 226407-20-1

By formula: (CAS Reg. No. 226407-20-1 • 4294967295CF) + CF = CAS Reg. No. 226407-20-1

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	21.9 ± 1.1	kcal/mol	CIDT	Jesinger and Squires, 1999	gas phase

Constants of diatomic molecules

Go To: Top, Reaction thermochemistry data, References, Notes

Data compiled by: Klaus P. Huber and Gerhard H. Herzberg

Data collected through August, 1976

Symbols used in the table of constants
Symbol	Meaning
State	electronic state and / or symmetry symbol
T_e	minimum electronic energy (cm^-1)
ω_e	vibrational constant – first term (cm^-1)
ω_ex_e	vibrational constant – second term (cm^-1)
ω_ey_e	vibrational constant – third term (cm^-1)
B_e	rotational constant in equilibrium position (cm^-1)
α_e	rotational constant – first term (cm^-1)
γ_e	rotation-vibration interaction constant (cm^-1)
D_e	centrifugal distortion constant (cm^-1)
β_e	rotational constant – first term, centrifugal force (cm^-1)
r_e	internuclear distance (Å)
Trans.	observed transition(s) corresponding to electronic state
ν₀₀	position of 0-0 band (units noted in table)

Diatomic constants for ¹²C¹⁹F
State	T_e	ω_e	ω_ex_e	ω_ey_e	B_e	α_e	γ_e	D_e	β_e	r_e	Trans.	ν₀₀
Fragments of additional systems in the absorption spectrum above 50000 cm^-1.
↳Mathews, 1971
C' ²Σ⁺					[1.5327] 1			[3.3E-6]		1.223	C' ← X V	53597.0
C' ²Σ⁺	↳Mathews, 1971
D ²Π	52272.5 2	1803.9 Z	13.0		1.7301	0.0193		6.5E-6		1.1510	D ← X V	52519.9 3
D ²Π	↳Mathews, 1971
B ²Δ_r	49399.6 4	[1153.3₄] Z	19.48 H	-0.4	1.320₆ 5	0.022₈		4.0E-6		1.317₄	B ↔ X 6 R	49340.1 7 Z
B ²Δ_r	↳missing citation; Margrave and Wieland, 1953; missing citation
State	T_e	ω_e	ω_ex_e	ω_ey_e	B_e	α_e	γ_e	D_e	β_e	r_e	Trans.	ν₀₀
A ²Σ⁺	42692.9	1780.4₅ Z	30.7₃		1.7228 8	0.0189 9	-0.0028	[6.80E-6] 10		1.1535	A ↔ X 11 V	42924.17 12 Z
A ²Σ⁺	↳missing citation; Margrave and Wieland, 1953; Mann, Broida, et al., 1954; Kuzyakov and Tatevskii, 1958; Thrush and Zwolenik, 1963; Porter, Mann, et al., 1965; Mathews, 1971
a ⁴Σ^-	(22000) 13	(1324) 13	(11) 13		(1.302) 13	(0.013) 13
X ²Π_r	0 14	1308.1 Z	11.10 15	0.093	1.4172 16	0.0184₀	0.00011	6.5E-6		1.2718 17
X ²Π_r	↳Carrington and Howard, 1970

Notes

Line width increases with N. Vibrational numbering uncertain.

A ~ +0.2 or +6.5.

By extrapolation from the 1-0,2-0, and 3-0 bands; the 0-0 band was not observed.

A₀= +0.76. The alternative value, A₀= +4.48, leads to disagreement between observed and calculated relative line intensities Mathews, 1971.

Strong perturbations in v=2 Mathews, 1971.

Radiative lifetime τ(v'=0) = 18.₈ ns Hesser and Dressler, 1966, Hesser, 1968; f₀₀(B←x) =0.022 (recalculated for a ²Δ upper state). See also Wentink and Isaacson, 1967.

J'=3/2 (average of {F₁} and F₂) relative to J"=1/2 (average of F₁ and {F₂}). The band centers in Carroll and Grennan, 1970 must all be reduced by 1.4 cm^-1 Mathews, 1971 owing to an error resulting from the incorrect application of the vacuum correction.

Predissociation above v=1, due to a curve crossing with the a ⁴Σ^- state at an internuclear distance smaller than r_e: see Mathews, 1971, Hall and Richards, 1972.

(B₀ and B₁ from Porter, Mann, et al., 1965, B₂ from Mathews, 1971).

D₁= 7.1₀E-6 Porter, Mann, et al., 1965, D₂= 9.0₀E-6 Mathews, 1971.

Radiative lifetime τ(v'=1) = 19.₀ ns Hesser and Dressler, 1966, Hesser, 1968, f₀₀(A←X) ~ 0.0027, f_el ~ 0.026 Harrington, Modica, et al., 1966, Hesser, 1968. See also Wentink and Isaacson, 1967.

N'=0 relative to J"=1/2 (average of F"₁ and {F"₂}).

Preliminary results of theoretical calculations Mathews, 1971, Hall and Richards, 1972.

A_v=77.12 - 0.655v + 0.0057v².

w_ez_e = - 0.0011

Λ-type doubling; see Porter, Mann, et al., 1965.

ESR sp. (²Π_3/2)^u

Thermochemical value (mass-spectrom.) Hildenbrand, 1975. From the predissociation in A ²Σ⁺; D₀⁰ ≤ 5.74 eV.

Photoionization Walter, Lifshitz, et al., 1969 and electron impact Hildenbrand, 1975 appearance potential measurements; supported by theoretical calculations O'Hare and Wahl, 1971.

μ_el(C^-F⁺)= 0.65 D; polarity predicted by the theoretical work of O'Hare and Wahl, 1971 and Hall and Richards, 1972.

References

Go To: Top, Reaction thermochemistry data, Constants of diatomic molecules, Notes

Schwartz, Davico, et al., 1999
Schwartz, R.L.; Davico, G.E.; Ramond, T.M.; Lineberger, W.C., Singlet-triplet splittings in CX2 (X = F, Cl, Br, I) dihalocarbenes via negative ion photoelectron spectroscopy, J. Phys. Chem. A, 1999, 103, 41, 8213-8221, https://doi.org/10.1021/jp992214c . [all data]

Murray, Leopold, et al., 1988
Murray, K.K.; Leopold, D.G.; Miller, T.M.; Lineberger, W.C., Photoelectron Spectroscopy of the Halocarbene Anions HCF^-, HCCl^-, HCBr^-, HCI^-, CF₂^-, and CCl₂^-, J. Chem. Phys., 1988, 89, 9, 5442, https://doi.org/10.1063/1.455596 . [all data]

Jesinger and Squires, 1999
Jesinger, R.A.; Squires, R.R., Carbyne thermochemistry from energy-resolved collision-induced dissociation. The heats of formation of CH, CF, and CCl, Int. J. Mass Spectrom., 1999, 187, 745-757, https://doi.org/10.1016/S1387-3806(98)14182-9 . [all data]

Mathews, 1971
Mathews, C.W., Private communication cited in Huber and Herzberg, 1979, 1971, 139. [all data]

Margrave and Wieland, 1953
Margrave, J.L.; Wieland, K., Equilibria involving the CF(g) and CF₂(g) radicals at high temperatures, J. Chem. Phys., 1953, 21, 1552. [all data]

Mann, Broida, et al., 1954
Mann, D.E.; Broida, H.P.; Squires, B.E., The decomposition of CF₄ flames, J. Chem. Phys., 1954, 22, 348. [all data]

Kuzyakov and Tatevskii, 1958
Kuzyakov, Yu.Ya.; Tatevskii, V.M., New bands of the CF molecule, Opt. Spektrosk., 1958, 5, 699. [all data]

Thrush and Zwolenik, 1963
Thrush, B.A.; Zwolenik, J.J., Predissociation in the absorption spectra of CF and CF2, Trans. Faraday Soc., 1963, 59, 582, https://doi.org/10.1039/tf9635900582 . [all data]

Porter, Mann, et al., 1965
Porter, T.L.; Mann, D.E.; Acquista, N., Emission spectrum of CF, J. Mol. Spectrosc., 1965, 16, 228. [all data]

Carrington and Howard, 1970
Carrington, A.; Howard, B.J., Gas-phase electron resonance spectrum and dipole moment of CF, Mol. Phys., 1970, 18, 225. [all data]

Hesser and Dressler, 1966
Hesser, J.E.; Dressler, K., Radiative lifetimes of ultraviolet molecular transitions, J. Chem. Phys., 1966, 45, 3149. [all data]

Hesser, 1968
Hesser, J.E., Absolute Transition Probabilities in Ultraviolet Molecular Spectra, J. Chem. Phys., 1968, 48, 6, 2518, https://doi.org/10.1063/1.1669477 . [all data]

Wentink and Isaacson, 1967
Wentink, T., Jr.; Isaacson, L., Oscillator strengths of CF and comments on heats of formation of CF and CF₂, J. Chem. Phys., 1967, 46, 603. [all data]

Carroll and Grennan, 1970
Carroll, P.K.; Grennan, T.P., The B-X system of CF, J. Phys. B:, 1970, 3, 865. [all data]

Hall and Richards, 1972
Hall, J.A.; Richards, W.G., A theoretical study of the spectroscopic states of the CF molecule, Mol. Phys., 1972, 23, 331. [all data]

Harrington, Modica, et al., 1966
Harrington, J.A.; Modica, A.P.; Libby, D.R., Erratum: Shock-tube determination of the C₂(A³Π → X³Π) and CF(A²Σ⁺ → X²Π) band-system oscillator strengths, J. Chem. Phys., 1966, 45, 2720. [all data]

Hildenbrand, 1975
Hildenbrand, D.L., Dissociation energy and ionization potential of the molecule CF, Chem. Phys. Lett., 1975, 32, 523. [all data]

Walter, Lifshitz, et al., 1969
Walter, T.A.; Lifshitz, C.; Chupka, W.A.; Berkowitz, J., Mass-spectrometric study of the photoionization of C₂F₄ and CF₄, J. Chem. Phys., 1969, 51, 3531. [all data]

O'Hare and Wahl, 1971
O'Hare, P.A.G.; Wahl, A.C., Molecular orbital investigation of CF and SiF and their positive and negative ions, J. Chem. Phys., 1971, 55, 666. [all data]

Huber and Herzberg, 1979
Huber, K.P.; Herzberg, G., Molecular Spectra and Molecular Structure. IV. Constants of Diatomic Molecules, Van Nostrand Reinhold Company, New York, 1979, 716. [all data]

Notes

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Symbols used in this document:

Δ_rH° Enthalpy of reaction at standard conditions
Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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