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:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Phase change data
  • Reaction thermochemistry data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • Vibrational and/or electronic energy levels
  • References
  • Notes
• Other data available:
  • Henry's Law data
  • Gas phase ion energetics data
  • Ion clustering data
  • Gas Chromatography
• Data at other public NIST sites:
  • Computational Chemistry Comparison and Benchmark Database
  • 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.

Gas phase thermochemistry data

Go To: Top, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, IR Spectrum, Mass spectrum (electron ionization), 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:
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 (J/mol*K)
    H° = standard enthalpy (kJ/mol)
    S° = standard entropy (J/mol*K)
    t = temperature (K) / 1000.

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

View table.

Condensed phase thermochemistry data

Go To: Top, Gas phase thermochemistry data, Phase change data, Reaction thermochemistry data, IR Spectrum, Mass spectrum (electron ionization), 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: Eugene S. Domalski and Elizabeth D. Hearing

Constant pressure heat capacity of liquid

Phase change data

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Reaction thermochemistry data, IR Spectrum, Mass spectrum (electron ionization), 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

Reaction thermochemistry data

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, IR Spectrum, Mass spectrum (electron ionization), 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:
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
ALS - 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: H₄N⁺ + C₂N₂ = (H₄N⁺ • C₂N₂)

Free energy of reaction

 +  = 2

By formula: C₂N₂ + C₂F₆ = 2C₂F₃N

IR Spectrum

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Mass spectrum (electron ionization), Vibrational and/or electronic energy levels, References, Notes

Data compiled by: Coblentz Society, Inc.

• GAS; Not specified, most likely a prism, grating, or hybrid spectrometer.; DIGITIZED BY NIST FROM HARD COPY; 4 cm^-1 resolution
• GAS (280 mmHg DILUTED TO A TOTAL PRESSURE OF 600 mmHg WITH N2); DOW KBr FOREPRISM-GRATING; DIGITIZED BY NIST FROM HARD COPY (FROM TWO SEGMENTS); 4 cm^-1 resolution
• GAS (280 mmHg, N2 ADDED, TOTAL PRESSURE 600 mmHg); DOW KBr FOREPRISM-GRATING; DIGITIZED BY NIST FROM HARD COPY (FROM TWO SEGMENTS); 2 cm^-1 resolution

Mass spectrum (electron ionization)

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, IR Spectrum, 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: NIST Mass Spectrometry Data Center, William E. Wallace, director

Spectrum

Notice: This spectrum may be better viewed with a Javascript and HTML 5 enabled browser.

For Zoom

1.) Enter the desired X axis range (e.g., 100, 200)

2.) Check here for automatic Y scaling

3.) Press here to zoom

Additional Data

Vibrational and/or electronic energy levels

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

Knowlton and Prosen, 1951
Knowlton, J.W.; Prosen, E.J., Heat of combustion and formation of cyanogen, J. Res. NBS, 1951, 46, 489-495. [all data]

McMorris and Badger, 1933
McMorris, J.; Badger, R.M., The heat of combustion, entropy and free energy of cyanogen gas, J. Am. Chem. Soc., 1933, 55, 1952-1957. [all data]

Wartenberg and Schutza, 1933
Wartenberg, H.V.; Schutza, H., Die verbrennungswarme des cyans, Z. Phys. Chem., 1933, 164, 386-388. [all data]

Cox and Pilcher, 1970
Cox, J.D.; Pilcher, G., Thermochemistry of Organic and Organometallic Compounds, Academic Press, New York, 1970, 1-636. [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, 2940-2944. [all data]

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, 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, 2940-4. [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]

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]

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]

Walker, Sinke, et al., 1970
Walker, L.C.; Sinke, G.C.; Perettie, D.J.; Janz, G.J., Enthalpy of formation of trifluoroacetonitrile, J. Am. Chem. Soc., 1970, 92, 4525-4526. [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, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, IR Spectrum, Mass spectrum (electron ionization), Vibrational and/or electronic energy levels, References

• Symbols used in this document:
  

  Cp,liquid	Constant pressure heat capacity of liquid
  Ptriple	Triple point pressure
  S°gas,1 bar	Entropy of gas at standard conditions (1 bar)
  S°liquid	Entropy of liquid at standard conditions
  T	Temperature
  Tboil	Boiling point
  Ttriple	Triple point temperature
  ΔcH°gas	Enthalpy of combustion of gas at standard conditions
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  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.