Methylene, difluoro-

Formula: CF₂
Molecular weight: 50.0075
IUPAC Standard InChI: InChI=1S/CF2/c2-1-3
IUPAC Standard InChIKey: LTVOKYUPTHZZQH-UHFFFAOYSA-N
CAS Registry Number: 2154-59-8
Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
The 3d structure may be viewed using Java or Javascript.
Other names: Calcium difluoride; Difluoromethylene
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Reaction thermochemistry data

Go To: Top, Vibrational and/or electronic energy levels, References, Notes

Data compiled by: John E. Bartmess

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.

Individual Reactions

(CF₃^- • 4294967295 Methylene, difluoro- ) + = CF₃^-

By formula: (CF₃^- • 4294967295CF₂) + CF₂ = CF₃^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	208. ± 10.	kJ/mol	N/A	Deyerl, Alconcel, et al., 2001	gas phase; Adiabatic EA, from vibrational structure of spectrum
Δ_rH°	213. ± 12.	kJ/mol	N/A	Bartmess, Scott, et al., 1979	gas phase; Paulino and Squires, 1991 suggests that this acidity may be too weak by ca. 5 kcal/mol. However, G2 calcn(JEB) give ΔHacid=379.9, ΔGacid=372.0; value altered from reference due to change in acidity scale
Δ_rH°	234. ± 11.	kJ/mol	CIDT	Paulino and Squires, 1991	gas phase; Neutral heat is based on a fluoroform acidity that may be too weak by up to 5 kcal/mol

(CAS Reg. No. 53959-80-1 • 4294967295 Methylene, difluoro- ) + = CAS Reg. No. 53959-80-1

By formula: (CAS Reg. No. 53959-80-1 • 4294967295CF₂) + CF₂ = CAS Reg. No. 53959-80-1

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	<33.5	kJ/mol	CIDT	Paulino and Squires, 1991, 2	gas phase; Probably CF2..Cl-, non-covalent.

Vibrational and/or electronic energy levels

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

Data compiled by: Marilyn E. Jacox

State: B ?

Energy (cm^-1)		Med.	Transition	λ_min (nm)	λ_max (nm)	References


T_o = 72740	T	gas	B-X	131	138	Mathews, 1967

State: A

Energy (cm^-1)	Med.	Transition	λ_min (nm)	λ_max (nm)	References


T_o = 37216	gas	A-X	220	380	Venkateswarlu, 1950
					Laird, Andrews, et al., 1950
					Mann and Thrush, 1960
					Thrush and Zwolenik, 1963
					Mathews, 1967
					King, Schenck, et al., 1979
					Cameron, Kable, et al., 1995
					Wang, Chen, et al., 1998
T_o = 37219 ± 2	Ne				Bondybey, 1976
T_o = 36878 ± 2	Ar	A-X	210	346	Bass and Mann, 1962
					Milligan, Mann, et al., 1964
					Smith, Jacox, et al., 1976
					Bondybey, 1976
T_o = 37054 ± 2	N₂				Bondybey, 1976

Vib. sym.	No.	Approximate type of mode	cm^-1	Med.	Method	References


a₁	1	Sym. stretch	1012.1 ± 0.5	gas	LF	Cameron, Kable, et al., 1995 Wang, Chen, et al., 1998
	2	Bend	496.7 ± 0.5	gas	UV LF	Venkateswarlu, 1950 Laird, Andrews, et al., 1950 Mann and Thrush, 1960 Thrush and Zwolenik, 1963 Mathews, 1967 Wang, Chen, et al., 1998
	2	Bend	496 ± 2	Ne	LF	Bondybey, 1976
	2	Bend	496 ± 2	Ar	AB	Bass and Mann, 1962 Milligan, Mann, et al., 1964 Smith, Jacox, et al., 1976
	2	Bend	496 ± 2	Ar	LF	Bondybey, 1976
	2	Bend	496 ± 2	N₂	LF	Bondybey, 1976
b₂	3	Asym. stretch	1180.2 ± 0.5	gas	LF	Cameron, Kable, et al., 1995 Wang, Chen, et al., 1998

State: a

Energy (cm^-1)	Med.	Transition	λ_min (nm)	λ_max (nm)	References


T_o = 19828	gas	a-X	430	800	Koda, 1978
					Koda, 1979
					Toby and Toby, 1980
					Koda, 1982
					Zhou, Zhan, et al., 1985
					Murray, Leopold, et al., 1988
					Schwartz, Davico, et al., 1999

Vib. sym.	No.	Approximate type of mode	cm^-1	Med.	Method	References


a₁	1	Sym. stretch	1020 ± 30	gas	PE	Schwartz, Davico, et al., 1999
	2	Bend	517	gas	CL	Koda, 1978 Toby and Toby, 1980 Koda, 1982 Zhou, Zhan, et al., 1985 Schwartz, Davico, et al., 1999

State: B

No.	Approximate type of mode	cm^-1	Med.	Method	References


2	Bend	625	gas	AB	Mathews, 1967

State: X

Vib. sym.	No.	Approximate type of mode	cm^-1		Med.	Method	References


a₁	1	Sym. stretch	1225.08		gas	DL IR	Davies, Lewis-Bevan, et al., 1981 Orlando, Reid, et al., 1987 Burkholder, Howard, et al., 1988 Wormhoudt, McCurdy, et al., 1989
	1	Sym. stretch	1225.08		gas	PE	Murray, Leopold, et al., 1988
	1	Sym. stretch	1221.9		Ne	IR LF	Snelson, 1970 Bondybey, 1976 Forney, Jacox, et al., 1994
	1	Sym. stretch	1222	vs	Ar	IR LF	Milligan, Mann, et al., 1964 Milligan and Jacox, 1968 Bondybey, 1976
	2	Bend	666.25		gas	UV DL	Venkateswarlu, 1950 Mathews, 1967 Murray, Leopold, et al., 1988 Qian and Davies, 1995
	2	Bend	668	w	Ar	IR LF	Milligan, Mann, et al., 1964 Milligan and Jacox, 1968 Bondybey, 1976
b₂	3	Asym.stretch	1114.44		gas	IR DL	Herr and Pimentel, 1965 Lefohn and Pimentel, 1971 Davies, Hamilton, et al., 1983 Burkholder, Howard, et al., 1988 Suto and Steinfeld, 1990
	3	Asym.stretch	1105.8		Ne	IR	Snelson, 1970 Forney, Jacox, et al., 1994
	3	Asym. stretch	1102	vs	Ar	IR	Milligan, Mann, et al., 1964 Milligan and Jacox, 1968

Additional references: Jacox, 1994, page 97; Jacox, 1998, page 196; Jacox, 2003, page 137; Powell and Lide, 1966; Mathews, 1966; Basco and Hathorn, 1971; Kirchhoff, Lide, et al., 1973; Akins, King, et al., 1979; Duignan, Hudgens, et al., 1982; Charo and De Lucia, 1982; Hack and Langel, 1983; Hack and Wilms, 1986; Booth and Hancock, 1988; Ibuki, Hiraya, et al., 1989; Hermann, 1990; Creasey, Lambert, et al., 1990; Cameron and Kable, 1998; Hansen, Mader, et al., 2000

Notes

Weak

Very strong

Tentative assignment or approximate value

Energy separation between the v = 0 levels of the excited and electronic ground states.

References

Go To: Top, Reaction thermochemistry data, Vibrational and/or electronic energy levels, Notes

Deyerl, Alconcel, et al., 2001
Deyerl, H.J.; Alconcel, L.S.; Continetti, R.E., Photodetachment imaging studies of the electron affinity of CF3, J. Phys. Chem. A, 2001, 105, 3, 552-557, https://doi.org/10.1021/jp003137k . [all data]

Bartmess, Scott, et al., 1979
Bartmess, J.E.; Scott, J.A.; McIver, R.T., Jr., The gas phase acidity scale from methanol to phenol, J. Am. Chem. Soc., 1979, 101, 6047. [all data]

Paulino and Squires, 1991
Paulino, J.A.; Squires, R.R., Carbene Thermochemistry from Collision-Induced Dissociation Threshold Energy Measurements - The Heats of Formation of X1A1 CF2 and X1A1 CCl2, J. Am. Chem. Soc., 1991, 113, 15, 5573, https://doi.org/10.1021/ja00015a009 . [all data]

Paulino and Squires, 1991, 2
Paulino, J.A.; Squires, R.R., Carbene Anion Complexes - Unusual Structural and Thermochemical Features of alpha-Halocarbanions in the Gas Phase, J. Am. Chem. Soc., 1991, 113, 5, 1845, https://doi.org/10.1021/ja00005a067 . [all data]

Mathews, 1967
Mathews, C.W., THE ABSORPTION SPECTRUM OF CF, Can. J. Phys., 1967, 45, 7, 2355, https://doi.org/10.1139/p67-188 . [all data]

Venkateswarlu, 1950
Venkateswarlu, P., On the Emission Bands of CF2, Phys. Rev., 1950, 77, 5, 676, https://doi.org/10.1103/PhysRev.77.676 . [all data]

Laird, Andrews, et al., 1950
Laird, R.K.; Andrews, E.B.; Barrow, R.F., The absorption spectrum of CF2, Trans. Faraday Soc., 1950, 46, 803, https://doi.org/10.1039/tf9504600803 . [all data]

Mann and Thrush, 1960
Mann, D.E.; Thrush, B.A., On the Absorption Spectrum of CF2 and Its Vibrational Analysis, J. Chem. Phys., 1960, 33, 6, 1732, https://doi.org/10.1063/1.1731493 . [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]

King, Schenck, et al., 1979
King, D.S.; Schenck, P.K.; Stephenson, J.C., Spectroscopy and photophysics of the CF2 system, J. Mol. Spectrosc., 1979, 78, 1, 1, https://doi.org/10.1016/0022-2852(79)90031-6 . [all data]

Cameron, Kable, et al., 1995
Cameron, M.R.; Kable, S.H.; Bacskay, G.B., The electronic spectroscopy of jet-cooled difluorocarbene (CF2): The missing A-state stretching frequencies, J. Chem. Phys., 1995, 103, 11, 4476, https://doi.org/10.1063/1.470728 . [all data]

Wang, Chen, et al., 1998
Wang, C.; Chen, C.; Dai, J.; Ma, X., Laser-induced fluorescence studies of jet-cooled CF2: determination of Ã-state stretching frequencies, Chem. Phys. Lett., 1998, 288, 2-4, 473, https://doi.org/10.1016/S0009-2614(98)00275-9 . [all data]

Bondybey, 1976
Bondybey, V.E., Vibrationally unrelaxed fluorescence in matrix isolated CF2, J. Mol. Spectrosc., 1976, 63, 2, 164, https://doi.org/10.1016/0022-2852(76)90002-3 . [all data]

Bass and Mann, 1962
Bass, A.M.; Mann, D.E., Absorption Spectrum of CF2 Trapped in an Argon Matrix, J. Chem. Phys., 1962, 36, 12, 3501, https://doi.org/10.1063/1.1732492 . [all data]

Milligan, Mann, et al., 1964
Milligan, D.E.; Mann, D.E.; Jacox, M.E.; Mitsch, R.A., Infrared Spectrum of CF2, J. Chem. Phys., 1964, 41, 5, 1199, https://doi.org/10.1063/1.1726051 . [all data]

Smith, Jacox, et al., 1976
Smith, C.E.; Jacox, M.E.; Milligan, D.E., The absorption and fluorescence spectra of matrix-isolated CF2, J. Mol. Spectrosc., 1976, 60, 1-3, 381, https://doi.org/10.1016/0022-2852(76)90141-7 . [all data]

Koda, 1978
Koda, S., Emission and energy transfer of triplet difluoromethylene produced in the reaction of oxygen atoms with tetrafluoroethylene, Chem. Phys. Lett., 1978, 55, 2, 353, https://doi.org/10.1016/0009-2614(78)87037-7 . [all data]

Koda, 1979
Koda, S., Mechanism of oxygen (3P) atom reaction with tetrafluoroethylene and quenching processes of the emission of difluoromethylene (3B1), J. Phys. Chem., 1979, 83, 16, 2065, https://doi.org/10.1021/j100479a004 . [all data]

Toby and Toby, 1980
Toby, S.; Toby, F.S., Singlet and triplet emission from difluoromethylene in the reaction of ozone with tetrafluorethene, J. Phys. Chem., 1980, 84, 2, 206, https://doi.org/10.1021/j100439a016 . [all data]

Koda, 1982
Koda, S., Initial vibrational distribution and relaxation of 3CF2 produced in the reaction of oxygen atoms with tetrafluoroethylene, Chem. Phys., 1982, 66, 3, 383, https://doi.org/10.1016/0301-0104(82)88038-5 . [all data]

Zhou, Zhan, et al., 1985
Zhou, S.; Zhan, M.; Qiu, Y.; Liu, S.; Shi, J.; Li, F.; Yao, J., Chemiluminescence of CF2(3B1) produced by the reaction O(3P) + C2F4, Chem. Phys. Lett., 1985, 121, 4-5, 395, https://doi.org/10.1016/0009-2614(85)87201-8 . [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]

Schwartz, Davico, et al., 1999
Schwartz, R.L.; Davico, G.E.; Ramond, T.M.; Lineberger, W.C., Singlet-Triplet Splittings in CX, J. Phys. Chem. A, 1999, 103, 41, 8213, https://doi.org/10.1021/jp992214c . [all data]

Davies, Lewis-Bevan, et al., 1981
Davies, P.B.; Lewis-Bevan, W.; Russell, D.K., Infrared diode laser spectrum of the ν1 band of CF2 (X 1A1), J. Chem. Phys., 1981, 75, 12, 5602, https://doi.org/10.1063/1.441998 . [all data]

Orlando, Reid, et al., 1987
Orlando, J.J.; Reid, J.; Smith, D.R., Time-resolved tunable diode laser detection of products of CF2HCl IRMPD: A linestrength measurement for CF2, Chem. Phys. Lett., 1987, 141, 5, 423, https://doi.org/10.1016/0009-2614(87)85053-4 . [all data]

Burkholder, Howard, et al., 1988
Burkholder, J.B.; Howard, C.J.; Hamilton, P.A., Fourier transform spectroscopy of the ν1 and ν3 fundamental bands of CF2, J. Mol. Spectrosc., 1988, 127, 2, 362, https://doi.org/10.1016/0022-2852(88)90126-9 . [all data]

Wormhoudt, McCurdy, et al., 1989
Wormhoudt, J.; McCurdy, K.E.; Burkholder, J.B., Measurements of the strengths of infrared bands of CF2, Chem. Phys. Lett., 1989, 158, 6, 480, https://doi.org/10.1016/0009-2614(89)87374-9 . [all data]

Snelson, 1970
Snelson, A., High Temp. Sci., 1970, 2, 70. [all data]

Forney, Jacox, et al., 1994
Forney, D.; Jacox, M.E.; Irikura, K.K., Matrix isolation study of the interaction of excited neon atoms with CF4. Infrared spectra of CF+3 and CF-3, J. Chem. Phys., 1994, 101, 10, 8290, https://doi.org/10.1063/1.468094 . [all data]

Milligan and Jacox, 1968
Milligan, D.E.; Jacox, M.E., Matrix-Isolation Study of the Reaction of Atomic and Molecular Fluorine with Carbon Atoms. The Infrared Spectra of Normal and 13C-Substituted CF2 and CF3, J. Chem. Phys., 1968, 48, 5, 2265, https://doi.org/10.1063/1.1669423 . [all data]

Qian and Davies, 1995
Qian, H.-B.; Davies, P.B., Infrared Laser Spectroscopy of the ν2 Band of Difluorocarbene (CF2), J. Mol. Spectrosc., 1995, 169, 1, 201, https://doi.org/10.1006/jmsp.1995.1016 . [all data]

Herr and Pimentel, 1965
Herr, K.C.; Pimentel, G.C., A Rapid-Scan Infrared Spectrometer; Flash Photolytic Detection of Chloroformic Acid and of CF_2, Appl. Opt., 1965, 4, 1, 25, https://doi.org/10.1364/AO.4.000025 . [all data]

Lefohn and Pimentel, 1971
Lefohn, A.S.; Pimentel, G.C., Infrared Spectrum of Gaseous CF2 by Rapid Scan Spectroscopy, J. Chem. Phys., 1971, 55, 3, 1213, https://doi.org/10.1063/1.1676207 . [all data]

Davies, Hamilton, et al., 1983
Davies, P.B.; Hamilton, P.A.; Elliott, J.M.; Rice, M.J., Infrared diode laser spectroscopy of the ν3 band of CF2, J. Mol. Spectrosc., 1983, 102, 1, 193, https://doi.org/10.1016/0022-2852(83)90237-0 . [all data]

Suto and Steinfeld, 1990
Suto, O.; Steinfeld, J., Time-resolved diode laser absorption spectroscopy of CF2 produced in UV photodissociation of C2F4 and measurement of ν3 absorption band strength, Chem. Phys. Lett., 1990, 168, 2, 181, https://doi.org/10.1016/0009-2614(90)85126-W . [all data]

Jacox, 1994
Jacox, M.E., Vibrational and electronic energy levels of polyatomic transient molecules, American Chemical Society, Washington, DC, 1994, 464. [all data]

Jacox, 1998
Jacox, M.E., Vibrational and electronic energy levels of polyatomic transient molecules: supplement A, J. Phys. Chem. Ref. Data, 1998, 27, 2, 115-393, https://doi.org/10.1063/1.556017 . [all data]

Jacox, 2003
Jacox, M.E., Vibrational and electronic energy levels of polyatomic transient molecules: supplement B, J. Phys. Chem. Ref. Data, 2003, 32, 1, 1-441, https://doi.org/10.1063/1.1497629 . [all data]

Powell and Lide, 1966
Powell, F.X.; Lide, D.R., Jr., Microwave Spectrum of CF2, J. Chem. Phys., 1966, 45, 3, 1067, https://doi.org/10.1063/1.1727662 . [all data]

Mathews, 1966
Mathews, C.W., 2500-… Absorption Spectrum of CF2, J. Chem. Phys., 1966, 45, 3, 1068, https://doi.org/10.1063/1.1727663 . [all data]

Basco and Hathorn, 1971
Basco, N.; Hathorn, F.G.M., The electronic absorption spectrum of the trifluoromethyl radical, Chem. Phys. Lett., 1971, 8, 3, 291, https://doi.org/10.1016/0009-2614(71)85015-7 . [all data]

Kirchhoff, Lide, et al., 1973
Kirchhoff, W.H.; Lide, D.R., Jr.; Powell, F.X., The microwave spectrum, force field and dipole moment of CF2, J. Mol. Spectrosc., 1973, 47, 3, 491, https://doi.org/10.1016/0022-2852(73)90096-9 . [all data]

Akins, King, et al., 1979
Akins, D.L.; King, D.S.; Stephenson, J.C., Vibrational relaxation of CF2(ν2 = 1--6 in non-reactive collisions, Chem. Phys. Lett., 1979, 65, 2, 257, https://doi.org/10.1016/0009-2614(79)87060-8 . [all data]

Duignan, Hudgens, et al., 1982
Duignan, M.T.; Hudgens, J.W.; Wyatt, J.R., Multiphoton ionization of the trifluoromethyl radical, J. Phys. Chem., 1982, 86, 21, 4156, https://doi.org/10.1021/j100218a013 . [all data]

Charo and De Lucia, 1982
Charo, A.; De Lucia, F.C., The millimeter and submillimeter spectrum of CF2 and its production in a dc glow discharge, J. Mol. Spectrosc., 1982, 94, 2, 363, https://doi.org/10.1016/0022-2852(82)90012-1 . [all data]

Hack and Langel, 1983
Hack, H.; Langel, W., Photophysics of difluoromethylene (~A 1B1 (0,6,0)) excited by a krypton fluoride laser at 248 nm. 3. Direct measurements of 1B1 collisional removal rates, J. Phys. Chem., 1983, 87, 18, 3462, https://doi.org/10.1021/j100241a022 . [all data]

Hack and Wilms, 1986
Hack, W.; Wilms, A., Photophysics of difluoromethylene (A1B1(0,2,0)). 4. Deactivation processes for single rotational states, J. Phys. Chem., 1986, 90, 17, 4007, https://doi.org/10.1021/j100408a036 . [all data]

Booth and Hancock, 1988
Booth, J.P.; Hancock, G., The radiative lifetime of CF(A 2Σ+), Chem. Phys. Lett., 1988, 150, 5, 457, https://doi.org/10.1016/0009-2614(88)87229-4 . [all data]

Ibuki, Hiraya, et al., 1989
Ibuki, T.; Hiraya, A.; Shobatake, K., Photochemistry of CCl3F and CCl2F2 in the 106--200 nm region, J. Chem. Phys., 1989, 90, 11, 6290, https://doi.org/10.1063/1.456345 . [all data]

Hermann, 1990
Hermann, R., Radiat. Phys. Chem., 1990, 36, 227. [all data]

Creasey, Lambert, et al., 1990
Creasey, J.C.; Lambert, I.R.; Tuckett, R.P.; Hopkirk, A., Vacuum UV spectroscopy and dynamics of CHF, Mol. Phys., 1990, 71, 6, 1355, https://doi.org/10.1080/00268979000102531 . [all data]

Cameron and Kable, 1998
Cameron, M.R.; Kable, S.H., Rotational State Dependent Fluorescence Lifetimes in CF2, J. Mol. Spectrosc., 1998, 192, 2, 449, https://doi.org/10.1006/jmsp.1998.7698 . [all data]

Hansen, Mader, et al., 2000
Hansen, N.; Mader, H.; Temps, F., Nuclear spin--rotation interaction in CF2 () observed by Fourier transform microwave spectroscopy, Chem. Phys. Lett., 2000, 327, 1-2, 97, https://doi.org/10.1016/S0009-2614(00)00840-X . [all data]

Notes

Go To: Top, Reaction thermochemistry data, Vibrational and/or electronic energy levels, References

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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