Methylene, difluoro-

• Formula: CF₂
• Molecular weight: 50.0075
• IUPAC Standard InChI: InChI=1S/CF2/c2-1-3 Copy

  
• IUPAC Standard InChIKey: LTVOKYUPTHZZQH-UHFFFAOYSA-N Copy
• 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
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Gas phase thermochemistry data
  • Reaction thermochemistry data
  • Vibrational and/or electronic energy levels
  • References
  • Notes
• Other data available:
  • Gas phase ion energetics data
  • Ion clustering data
• Data at other public NIST sites:
  • Microwave spectra (on physics lab web site)
  • Electron-Impact Ionization Cross Sections (on physics web site)
  • Gas Phase Kinetics Database
  • X-ray Photoelectron Spectroscopy Database, version 5.0
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Gas phase thermochemistry data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Gas Phase Heat Capacity (Shomate Equation)

C_p° = A + B*t + C*t² + D*t³ + E/t²
H° − H°_298.15= A*t + B*t²/2 + C*t³/3 + D*t⁴/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t²/2 + D*t³/3 − E/(2*t²) + G
    C_p = heat capacity (cal/mol*K)
    H° = standard enthalpy (kcal/mol)
    S° = standard entropy (cal/mol*K)
    t = temperature (K) / 1000.

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Reaction thermochemistry data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

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) +  = CF₃^-

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

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

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

Vibrational and/or electronic energy levels

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

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled by: Marilyn E. Jacox

State:   B ?

State:   A

State:   a

State:   B

State:   X

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

References

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

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Chase, 1998
Chase, M.W., Jr., NIST-JANAF Themochemical Tables, Fourth Edition, J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951. [all data]

Ehlert, 1969
Ehlert, T.C., Bonding in C₁ and C₂ fluroides, J. Phys. Chem., 1969, 73, 949-953. [all data]

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, Gas phase thermochemistry data, Reaction thermochemistry data, Vibrational and/or electronic energy levels, References

• Symbols used in this document:
  

  S°gas,1 bar	Entropy of gas at standard conditions (1 bar)
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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