Dicarbon

• Formula: C₂
• Molecular weight: 24.0214
• IUPAC Standard InChI: InChI=1S/C2/c1-2 Copy

  
• IUPAC Standard InChIKey: LBVWYGNGGJURHQ-UHFFFAOYSA-N Copy
• CAS Registry Number: 12070-15-4
• 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.
• 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
  • Gas phase ion energetics data
  • Ion clustering data
  • References
  • Notes
• Other data available:
  • Constants of diatomic molecules
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
• Options:
  • Switch to calorie-based units

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.

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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View table.

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 as indicated in comments:
B - John E. Bartmess
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias

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

(C₂H^- • 4294967295) +  = C₂H^-

By formula: (C₂H^- • 4294967295C₂) + C₂ = C₂H^-

( • 2) +  = ( •  • 2)

By formula: (C⁺ • 2C) + C₂ = (C⁺ • C₂ • 2C)

C₆₂⁺ +  = (C₆₂⁺ • )

By formula: C₆₂⁺ + C₂ = (C₆₂⁺ • C₂)

C₅₈⁺ +  = (C₅₈⁺ • )

By formula: C₅₈⁺ + C₂ = (C₅₈⁺ • C₂)

C₆₀⁺ +  = (C₆₀⁺ • )

By formula: C₆₀⁺ + C₂ = (C₆₀⁺ • C₂)

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:
LL - Sharon G. Lias and Joel F. Liebman
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
B - John E. Bartmess

View reactions leading to C₂⁺ (ion structure unspecified)

Electron affinity determinations

Ionization energy determinations

Ion clustering data

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics 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 as indicated in comments:
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
B - John E. Bartmess

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. Searches may be limited to ion clustering reactions. A general reaction search form is also available.

Clustering reactions

( • 2) +  = ( •  • 2)

By formula: (C⁺ • 2C) + C₂ = (C⁺ • C₂ • 2C)

(C₂H^- • 4294967295) +  = C₂H^-

By formula: (C₂H^- • 4294967295C₂) + C₂ = C₂H^-

C₅₈⁺ +  = (C₅₈⁺ • )

By formula: C₅₈⁺ + C₂ = (C₅₈⁺ • C₂)

C₆₀⁺ +  = (C₆₀⁺ • )

By formula: C₆₀⁺ + C₂ = (C₆₀⁺ • C₂)

C₆₂⁺ +  = (C₆₂⁺ • )

By formula: C₆₂⁺ + C₂ = (C₆₂⁺ • C₂)

References

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, 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]

Zhou, Garand, et al., 2007
Zhou, J.; Garand, E.; Neumark, D.M., Vibronic structure in C2H and C2D from anion slow electron velocity-map imaging spectroscopy, J. Chem. Phys., 2007, 127, 11, 114313, https://doi.org/10.1063/1.2768932 . [all data]

Ruscic and Berkowitz, 1990
Ruscic, B.; Berkowitz, J., Photoion-pair Formation and Photoelectron-induced Dissociative Attachment in C2H2: D0(HCC-H), J. Chem. Phys., 1990, 93, 8, 5586, https://doi.org/10.1063/1.459629 . [all data]

Gurvich, Veyts, et al.
Gurvich, L.V.; Veyts, I.V.; Alcock, C.B., Hemisphere Publishing, NY, 1989, V. 1 2, Thermodynamic Properties of Individual Substances, 4th Ed. [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]

Radi, Rincon, et al., 1989
Radi, P.P.; Rincon, M.E.; Hsu, M.T.; Brodbelt-Lustig, J.; Kemper, P.; Bowers, M.T., Structure, Reactivity and Energetics of Covalently Bound Carbon Cluster Ions, C5+ to C11+: Experiment and Theory, J. Phys. Chem., 1989, 93, 16, 6187, https://doi.org/10.1021/j100353a045 . [all data]

Radi, Hsu, et al., 1990
Radi, P.R.; Hsu, M.T.; Rincon, M.E.; Kemper, P.R.; Bowers, M.T., On the Structure, Reactivity and Relative Stability of the Large Carbon Cluster Ions C62+, C60+ and C58+, Chem. Phys. Lett., 1990, 174, 3-4, 223, https://doi.org/10.1016/0009-2614(90)85336-B . [all data]

Arnold, Bradforth, et al., 1991
Arnold, D.W.; Bradforth, S.E.; Kitsopoulos, T.N.; Neumark, D.M., Vibrationally Resolved Spectra of C2-C11 by Anion Photoelectron Spectroscopy, J. Chem. Phys., 1991, 95, 12, 8753, https://doi.org/10.1063/1.461211 . [all data]

Ervin, Gronert, et al., 1990
Ervin, K.M.; Gronert, S.; Barlow, S.E.; Gilles, M.K.; Harrison, A.G.; Bierbaum, V.M.; DePuy, C.H.; Lin, W.C., Bonds Strengths of Ethylene and Acetylene, J. Am. Chem. Soc., 1990, 112, 15, 5750, https://doi.org/10.1021/ja00171a013 . [all data]

Jones, Mead, et al., 1980
Jones, P.L.; Mead, R.D.; Kohler, B.E.; Rosner, S.D.; Lineberger, W.C., Photodetachment spectroscopy of C₂- autodetaching resonances, J. Chem. Phys., 1980, 73, 4419. [all data]

Yang, Taylor, et al., 1989
Yang, S.; Taylor, K.J.; Craycraft, M.J.; Conceicao, J.; Pettiette, C.L.; Cherhnovsky, O.; Smalley, R.E., UPS of 2-30 Atom Carbon Clusters: Chains and Rings, Chem. Phys. Lett., 1989, 144, 5-6, 431, https://doi.org/10.1016/0009-2614(88)87291-9 . [all data]

Feldman, 1970
Feldman, D., Photoablosung von Elektronen bei einigen Stabilen Negativen Ionen, Z. Naturfor., 1970, 25A, 621. [all data]

Locht and Momigny, 1970
Locht, R.; Momigny, J., Mass Spectrometric Determination of the Electron Affinities of Radicals, Chem. Phys. Lett., 1970, 6, 4, 273, https://doi.org/10.1016/0009-2614(70)85072-2 . [all data]

Trepka and Neuert, 1963
Trepka, L.v.; Neuert, H., Uber die Entstehenung von Negativen Ionen aus einigen Kohlenwasserstoffen und Alkoholen durch Elektronenstoss, Z. Naturfor., 1963, 18A, 1295. [all data]

Thynne and MacNiel, 1971
Thynne, J.C.J.; MacNiel, K.A.G., Negative ion formation by ethylene and 1,1-difluoroethylene, J. Phys. Chem., 1971, 75, 2584. [all data]

Honig, 1954
Honig, R.E., Mass spectrometric study of the molecular sublimation of graphite, J. Chem. Phys., 1954, 22, 126. [all data]

Reid, Ballantine, et al., 1995
Reid, C.J.; Ballantine, J.A.; Andrews, S.R.; Harris, F.M., Charge inversion of ground-state and metastable-state C₂⁺ cations formed from electroionised C₂H₂ and C₂N₂, and a re-evaluation of the carbon dimer's ionisation energy, Chem. Phys., 1995, 190, 113. [all data]

Plessis and Marmet, 1986
Plessis, P.; Marmet, P., Electroionization study of acetylene and fragment ions, Int. J. Mass Spectrom. Ion Processes, 1986, 70, 23. [all data]

Huber and Herzberg, 1979
Huber, K.P.; Herzberg, G., Molecular Spectra and Molecular Structure. IV. Constants of Diatomic Molecules,, Van Nostrand Reinhold Co., 1979, ,1. [all data]

Gupta and Gingerich, 1979
Gupta, S.K.; Gingerich, K.A., Observation and atomization energies of the gaseous uranium carbides, UC, UC₂, UC₃, UC₄, UC₅, and UC₆ by high temperature mass spectrometry, J. Chem. Phys., 1979, 71, 3072. [all data]

Cocke and Gingerich, 1974
Cocke, D.L.; Gingerich, K.A., Thermodynamic investigation of the gaseous molecules TiRh, Rh₂, and Ti₂Rh by mass spectrometry, J. Chem. Phys., 1974, 60, 1958. [all data]

Cocke and Gingerich, 1972
Cocke, D.L.; Gingerich, K.A., Mass spectrometric determination of the bond dissociation energies of the molecules CePd and CeC₂, J. Phys. Chem., 1972, 76, 2332. [all data]

Drowart, Burns, et al., 1959
Drowart, J.; Burns, R.P.; DeMaria, G.; Inghram, M.G., Mass spectrometric study of carbon vapor, J. Chem. Phys., 1959, 31, 1131. [all data]

Field, Franklin, et al., 1957
Field, F.H.; Franklin, J.L.; Lampe, F.W., Reactions of gaseous ions. II. Acetylene, J. Am. Chem. Soc., 1957, 79, 2665. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, References

• Symbols used in this document:
  

  EA	Electron affinity
  IE (evaluated)	Recommended ionization energy
  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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