Cyanogen

• Formula: C₂N₂
• Molecular weight: 52.0348
• IUPAC Standard InChI: InChI=1S/C2N2/c3-1-2-4 Copy

  
• IUPAC Standard InChIKey: JMANVNJQNLATNU-UHFFFAOYSA-N Copy
• CAS Registry Number: 460-19-5
• 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: Ethanedinitrile; Cyanogen (C2N2); Carbon nitride (C2N2); Dicyanogen; Nitriloacetonitrile; Oxalic acid dinitrile; Oxalonitrile; NCCN; Dicyan; Cyanogen gas; Carbon nitride; Cyanogene; Oxalic nitrile; Prussite; Rcra waste number P031; UN 1026; (CN)2; Oxalyl cyanide
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Phase change data
  • Gas phase ion energetics data
  • Ion clustering data
  • Vibrational and/or electronic energy levels
  • References
  • Notes
• Other data available:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Reaction thermochemistry data
  • Henry's Law data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • Gas Chromatography
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
• Options:
  • Switch to calorie-based units

Data at NIST subscription sites:

• NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)

NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.

Phase change data

Go To: Top, Gas phase ion energetics data, Ion clustering data, Vibrational and/or electronic energy levels, 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:
BS - Robert L. Brown and Stephen E. Stein
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
DH - Eugene S. Domalski and Elizabeth D. Hearing
AC - William E. Acree, Jr., James S. Chickos
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Enthalpy of vaporization

Entropy of vaporization

Antoine Equation Parameters

log₁₀(P) = A − (B / (T + C))
    P = vapor pressure (bar)
    T = temperature (K)

View plot Requires a JavaScript / HTML 5 canvas capable browser.

Enthalpy of sublimation

Enthalpy of fusion

Entropy of fusion

Gas phase ion energetics data

Go To: Top, Phase change data, Ion clustering data, Vibrational and/or electronic energy levels, References, Notes

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:
HL - Edward P. Hunter and Sharon G. Lias
L - Sharon G. Lias

Data compiled as indicated in comments:
MM - Michael M. Meot-Ner (Mautner)
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

Gas basicity at 298K

Ionization energy determinations

Appearance energy determinations

Ion clustering data

Go To: Top, Phase change data, Gas phase ion energetics data, Vibrational and/or electronic energy levels, 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: 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. Searches may be limited to ion clustering reactions. A general reaction search form is also available.

Clustering reactions

 +  = ( • )

By formula: H₄N⁺ + C₂N₂ = (H₄N⁺ • C₂N₂)

Free energy of reaction

Vibrational and/or electronic energy levels

Go To: Top, Phase change data, Gas phase ion energetics data, Ion clustering 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: Takehiko Shimanouchi

Symmetry:   D_xh     Symmetry Number σ = 2

Source: Shimanouchi, 1972

Notes

References

Go To: Top, Phase change data, Gas phase ion energetics data, Ion clustering 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.

Weast and Grasselli, 1989
CRC Handbook of Data on Organic Compounds, 2nd Editon, Weast,R.C and Grasselli, J.G., ed(s)., CRC Press, Inc., Boca Raton, FL, 1989, 1. [all data]

Majer and Svoboda, 1985
Majer, V.; Svoboda, V., Enthalpies of Vaporization of Organic Compounds: A Critical Review and Data Compilation, Blackwell Scientific Publications, Oxford, 1985, 300. [all data]

Ruehrwein and Giauque, 1939
Ruehrwein, R.A.; Giauque, W.F., The entropy of cyanogen heat capacity and vapor pressure of solid and liquid heats of fusion and vaporization, J. Am. Chem. Soc., 1939, 61, 2940-4. [all data]

Hamann, Mcmanamey, et al., 1953
Hamann, S.D.; Mcmanamey, W.J.; Pearse, J.F., The forces between polyatomic molecules, Trans. Faraday Soc., 1953, 49, 351. [all data]

Ruehrwein and Giauque, 1939, 2
Ruehrwein, R.A.; Giauque, W.F., The entropy of cyanogen. Heat capacity and vapor pressure of solid and liquid. Heats of fusion and vaporization, J. Am. Chem. Soc., 1939, 61, 2940-2944. [all data]

Stephenson and Malanowski, 1987
Stephenson, Richard M.; Malanowski, Stanislaw, Handbook of the Thermodynamics of Organic Compounds, 1987, https://doi.org/10.1007/978-94-009-3173-2 . [all data]

Ruehrwein and Giauque, 1939, 3
Ruehrwein, R.A.; Giauque, W.F., The entropy of cyanogen. Heat capacity and vapor pressure of solid and liquid. Heats of fusion and vaporization, J. Am. Chem. Soc., 1939, 61, 2940-29. [all data]

Perry and Bardwell, 1925
Perry, John H.; Bardwell, D.C., THE VAPOR PRESSURES OF SOLID AND LIQUID CYANOGEN ¹, J. Am. Chem. Soc., 1925, 47, 11, 2629-2632, https://doi.org/10.1021/ja01688a002 . [all data]

Stull, 1947
Stull, Daniel R., Vapor Pressure of Pure Substances. Organic and Inorganic Compounds, Ind. Eng. Chem., 1947, 39, 4, 517-540, https://doi.org/10.1021/ie50448a022 . [all data]

Govers, 1975
Govers, H.A.J., Derivation of carbon--nitrogen, hydrogen--nitrogen and nitrogen--nitrogen non-bonded potential parameters in molecular crystals, Acta Crystallogr Sect A Cryst Phys Diffr Theor Gen Crystallogr', 1975, 31, 3, 380-385, https://doi.org/10.1107/S0567739475000800 . [all data]

Domalski and Hearing, 1996
Domalski, Eugene S.; Hearing, Elizabeth D., Heat Capacities and Entropies of Organic Compounds in the Condensed Phase. Volume III, J. Phys. Chem. Ref. Data, 1996, 25, 1, 1, https://doi.org/10.1063/1.555985 . [all data]

Hunter and Lias, 1998
Hunter, E.P.; Lias, S.G., Evaluated Gas Phase Basicities and Proton Affinities of Molecules: An Update, J. Phys. Chem. Ref. Data, 1998, 27, 3, 413-656, https://doi.org/10.1063/1.556018 . [all data]

Milligan, Fairley, et al., 1998
Milligan, D.B.; Fairley, D.A.; Meot-Ner (Mautner), M.; McEwan, M.J., Proton affinity of cyanogen and association reactions of C2N2H+ and C2N2CH3+, Int. J. Mass Spectrom., 1998, 180, 285. [all data]

Smith, 1983
Smith, O.I., Cross sections for formation of parent and fragment ions by electron impact from C₂N₂, Int. J. Mass Spectrom. Ion Processes, 1983, 54, 55. [all data]

Baker and Turner, 1968
Baker, C.; Turner, D.W., High resolution molecular photoelectron spectroscopy. III.Acetylenes and azaacetylenes, Proc. Roy. Soc. (London), 1968, A308, 19. [all data]

Dibeler and Liston, 1967
Dibeler, V.H.; Liston, S.K., Mass-spectrometric study of photoionization. VIII.Dicyanogen and the cyanogen halides, J. Chem. Phys., 1967, 47, 4548. [all data]

Dorsch and Kallman, 1930
Dorsch, K.E.; Kallman, H., Uber die Ionisierung von Dicyan durch langsame Elektronen, Z. Phys., 1930, 60, 376. [all data]

Asbrink, Von Niessen, et al., 1980
Asbrink, L.; Von Niessen, W.; Bieri, G., 30.4-nm He(II) photoelectron spectra of organic molecules, J. Electron Spectrosc. Relat. Phenom., 1980, 21, 93. [all data]

Haney and Franklin, 1968
Haney, M.A.; Franklin, J.L., Correlation of excess energies of electron-impact dissociations with the translational energies of the products, J.Chem. Phys., 1968, 48, 4093. [all data]

Harland and McIntosh, 1985
Harland, P.W.; McIntosh, B.J., Enthalpies of formation for the isomeric ions H_xCCN⁺ and H_xCNC⁺ (x = 0-3) by monochromatic electron impact on C₂N₂, CH₃CN and CH₃NC., Int. J. Mass Spectrom. Ion Processes, 1985, 67, 29. [all data]

Dibeler, Reese, et al., 1961
Dibeler, V.H.; Reese, R.M.; Franklin, J.L., Mass spectrometric study of cyanogen and cyanoacetylenes, J. Am. Chem. Soc., 1961, 83, 1813. [all data]

Speller and Meot-Ner (Mautner), 1985
Speller, C.V.; Meot-Ner (Mautner), M., The Ionic Hydrogen Bond and Ion Solvation. 3. Bonds Involving Cyanides. Correlations with Proton Affinites, J. Phys. Chem., 1985, 81, 24, 5217, https://doi.org/10.1021/j100270a020 . [all data]

Shimanouchi, 1972
Shimanouchi, T., Tables of Molecular Vibrational Frequencies Consolidated Volume II, J. Phys. Chem. Ref. Data, 1972, 6, 3, 993-1102. [all data]

Notes

Go To: Top, Phase change data, Gas phase ion energetics data, Ion clustering data, Vibrational and/or electronic energy levels, References

• Symbols used in this document:
  

  AE	Appearance energy
  IE (evaluated)	Recommended ionization energy
  Ptriple	Triple point pressure
  T	Temperature
  Tboil	Boiling point
  Ttriple	Triple point temperature
  ΔfusH	Enthalpy of fusion
  ΔfusS	Entropy of fusion
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔrS°	Entropy of reaction at standard conditions
  ΔsubH	Enthalpy of sublimation
  ΔvapH	Enthalpy of vaporization
  ΔvapH°	Enthalpy of vaporization at standard conditions
  ΔvapS	Entropy of vaporization

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
• The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
• Customer support for NIST Standard Reference Data products.