Ethyne, dichloro-

• Formula: C₂Cl₂
• Molecular weight: 94.927
• IUPAC Standard InChI: InChI=1S/C2Cl2/c3-1-2-4 Copy

  
• IUPAC Standard InChIKey: ZMJOVJSTYLQINE-UHFFFAOYSA-N Copy
• CAS Registry Number: 7572-29-4
• 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.
• Species with the same structure:
  • Dichloroacetylene
• Other names: Acetylene, dichloro-; Dichloroacetylene; Dichloroethyne; ClC≡CCl; C2Cl2
• Information on this page:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Phase change data
  • Reaction thermochemistry data
  • Gas phase ion energetics data
  • Mass spectrum (electron ionization)
  • References
  • Notes
• Other data available:
  • Vibrational and/or electronic energy levels
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
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• NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)

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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:
DRB - Donald R. Burgess, Jr.

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 (J/mol*K)
    H° = standard enthalpy (kJ/mol)
    S° = standard entropy (J/mol*K)
    t = temperature (K) / 1000.

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Condensed 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 by: Donald R. Burgess, Jr.

Phase change 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:
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
DRB - Donald R. Burgess, Jr.

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: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

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

=  + 

By formula: C₂H₂Cl₂ = H₂ + C₂Cl₂

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 evaluated as indicated in comments:
L - Sharon G. Lias

Data compiled as indicated in comments:
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron

Ionization energy determinations

Appearance 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

References

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

Manion, 2002
Manion, J.A., Evaluated Enthalpies of Formation of the Stable Closed Shell C1 and C2 Chlorinated Hydrocarbons, J. Phys. Chem. Ref. Data, 2002, 31, 1, 123-172, https://doi.org/10.1063/1.1420703 . [all data]

Timmermans, 1952
Timmermans, J., Freezing points of organic compounds. VVI New determinations., Bull. Soc. Chim. Belg., 1952, 61, 393. [all data]

Laursen and Pimentel, 1989
Laursen, S.L.; Pimentel, G.C., Matrix-induced intersystem crossing in the photochemistry of the 1,2-dichloroethenes, J. Phys. Chem., 1989, 93, 2328-2333. [all data]

Maier and Thommen, 1984
Maier, J.P.; Thommen, F., Relaxation dynamics of open-shell cations studied by photoelectron-photon coincidence spectroscopy, Gas Phase Ion Chem., 1984, 3, 357. [all data]

Klapstein, Maier, et al., 1983
Klapstein, D.; Maier, J.P.; Zambach, W., Emission spectra of rotationally cooled dihaloacetylene cations in the gas phase: A²Π_(Ω,g) → x²Π_(Ω,u) band systems, Chem. Phys., 1983, 77, 463. [all data]

Bock, Ried, et al., 1981
Bock, H.; Ried, W.; Stein, U., Analyse und optimierung von gasphasen-reaktionen, 19. Pyrolyse von cyclobuten-1,2-dionen zu acetylenen, Chem. Ber., 1981, 114, 673. [all data]

Kloster-Jensen, Pascual, et al., 1970
Kloster-Jensen, E.; Pascual, C.; Vogt, J., Mass spectrometric studies of mono- and di-haloacetylenes,, Helv. Chim. Acta, 1970, 53, 2109. [all data]

Heilbronner, Hornung, et al., 1970
Heilbronner, E.; Hornung, V.; Kloster-Jensen, E., Die Photoelektron-Spektren der Dihalogen-acetylene, Helv. Chim. Acta, 1970, 53, 331. [all data]

Notes

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• Symbols used in this document:
  

  AE	Appearance energy
  IE (evaluated)	Recommended ionization energy
  S°gas,1 bar	Entropy of gas at standard conditions (1 bar)
  Tfus	Fusion (melting) point
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔfH°liquid	Enthalpy of formation of liquid at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔvapH°	Enthalpy of vaporization at standard conditions

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