Ethyne, difluoro-

• Formula: C₂F₂
• Molecular weight: 62.0182
• IUPAC Standard InChI: InChI=1S/C2F2/c3-1-2-4 Copy

  
• IUPAC Standard InChIKey: BWTZYYGAOGUPFQ-UHFFFAOYSA-N Copy
• CAS Registry Number: 689-99-6
• Chemical structure:
  This structure is also available as a 2d Mol file
• Other names: Acetylene, difluoro-; Difluoroacetylene; FC≡CF; Difluoroethyne; C2F2
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• Information on this page:
  • Gas phase thermochemistry data
  • Gas phase ion energetics data
  • Mass spectrum (electron ionization)
  • Vibrational and/or electronic energy levels
  • References
  • Notes
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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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Gas phase ion energetics 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:
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron

View reactions leading to C₂F₂⁺ (ion structure unspecified)

Ionization energy determinations

Mass spectrum (electron ionization)

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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: NIST Mass Spectrometry Data Center, William E. Wallace, director

Spectrum

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Additional Data

Vibrational and/or electronic energy levels

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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: Marilyn E. Jacox

State:   X

Additional references: Jacox, 1994, page 197

Notes

References

Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), 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]

Bieri, Schmelzer, et al., 1980
Bieri, G.; Schmelzer, A.; Asbrink, L.; Jonsson, M., Fluorine and the fluoroderivatives of acetylene and diacetylene studied by 30.4 nm He(II) photoelectron spectroscopy, Chem. Phys., 1980, 49, 213. [all data]

Bieri, Heilbronner, et al., 1977
Bieri, G.; Heilbronner, E.; Stadelmann, J.-P.; Vogt, J.; von Niessen, W., Electronic states of difluoroacetylene, difluorodiacetylene, and perfluoropentadiyne-1,3 radical cations. A photoelectron spectroscopic investigation, J. Am. Chem. Soc., 1977, 99, 6832. [all data]

Ehlert, 1969, 2
Ehlert, T.C., Bonding in C₁ and C₂ fluorides, J. Phys. Chem., 1969, 73, 949. [all data]

Burger, Schneider, et al., 1991
Burger, H.; Schneider, W.; Sommer, S.; Thiel, W.; Willner, H., The vibrational spectrum and rotational constants of difluoroethyne FC 3/4 CF. Matrix and high resolution infrared studies and ab initio calculations, J. Chem. Phys., 1991, 95, 8, 5660, https://doi.org/10.1063/1.461640 . [all data]

McNaughton and Elmes, 1992
McNaughton, D.; Elmes, P., Spectrochim. Acta, 1992, 48A, 605. [all data]

Burger and Sommer, 1992
Burger, H.; Sommer, S., The high-resolution infrared spectrum of FC«58876»CF: The 1350 and 2150 cm-1 regions, J. Mol. Spectrosc., 1992, 151, 1, 148, https://doi.org/10.1016/0022-2852(92)90011-C . [all data]

Brahms and Dailey, 1989
Brahms, J.C.; Dailey, W.P., Difluoromaleic anhydride as a source of matrix isolated difluoropropadienone, difluorocyclopropenone and difluoroacetylene, J. Am. Chem. Soc., 1989, 111, 24, 8940, https://doi.org/10.1021/ja00206a039 . [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]

Notes

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• 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

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