Cyanogen
- Formula: C2N2
- Molecular weight: 52.0348
- IUPAC Standard InChIKey: JMANVNJQNLATNU-UHFFFAOYSA-N
- 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
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Gas phase thermochemistry data
Go To: Top, Phase change data, Henry's Law 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 as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°gas | 309.07 | kJ/mol | Review | Chase, 1998 | Data last reviewed in March, 1961 |
ΔfH°gas | 308.9 ± 1.8 | kJ/mol | Ccb | Knowlton and Prosen, 1951 | ALS |
ΔfH°gas | 263. | kJ/mol | Cm | McMorris and Badger, 1933 | ALS |
ΔfH°gas | 306.7 ± 0.84 | kJ/mol | Ccb | Wartenberg and Schutza, 1933 | Reanalyzed by Cox and Pilcher, 1970, Original value = 305. ± 0.8 kJ/mol; ALS |
Quantity | Value | Units | Method | Reference | Comment |
ΔcH°gas | -1096.0 ± 1.8 | kJ/mol | Ccb | Knowlton and Prosen, 1951 | ALS |
ΔcH°gas | -1051.9 ± 5.0 | kJ/mol | Cm | McMorris and Badger, 1933 | ALS |
ΔcH°gas | -1093.7 ± 0.84 | kJ/mol | Ccb | Wartenberg and Schutza, 1933 | Reanalyzed by Cox and Pilcher, 1970, Original value = -1093. ± 0.8 kJ/mol; ALS |
Quantity | Value | Units | Method | Reference | Comment |
S°gas,1 bar | 241.57 | J/mol*K | Review | Chase, 1998 | Data last reviewed in March, 1961 |
Gas Phase Heat Capacity (Shomate Equation)
Cp° = 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
Cp = heat capacity (J/mol*K)
H° = standard enthalpy (kJ/mol)
S° = standard entropy (J/mol*K)
t = temperature (K) / 1000.
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Temperature (K) | 298. to 1300. | 1300. to 6000. |
---|---|---|
A | 51.69290 | 83.01014 |
B | 36.79351 | 2.209166 |
C | -12.46154 | -0.419735 |
D | 0.701803 | 0.027676 |
E | -0.428743 | -9.308648 |
F | 290.6951 | 264.0342 |
G | 291.2884 | 315.7192 |
H | 309.0725 | 309.0725 |
Reference | Chase, 1998 | Chase, 1998 |
Comment | Data last reviewed in March, 1961 | Data last reviewed in March, 1961 |
Phase change data
Go To: Top, Gas phase thermochemistry data, Henry's Law 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 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
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tboil | 252.0 | K | N/A | Weast and Grasselli, 1989 | BS |
Tboil | 252. | K | N/A | Majer and Svoboda, 1985 | |
Quantity | Value | Units | Method | Reference | Comment |
Ttriple | 245.32 | K | N/A | Ruehrwein and Giauque, 1939 | Uncertainty assigned by TRC = 0.02 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Ptriple | 0.751 | bar | N/A | Hamann, Mcmanamey, et al., 1953 | Uncertainty assigned by TRC = 0.0133 bar; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔvapH° | 20.8 | kJ/mol | N/A | Majer and Svoboda, 1985 |
Enthalpy of vaporization
ΔvapH (kJ/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
23.330 | 252.0 | N/A | Ruehrwein and Giauque, 1939, 2 | P = 101.325 kPa; DH |
23.33 | 252. | N/A | Majer and Svoboda, 1985 | |
24.5 | 246. | A | Stephenson and Malanowski, 1987 | Based on data from 240. to 253. K.; AC |
23.3 ± 0.2 | 251.95 | V | Ruehrwein and Giauque, 1939, 3 | ALS |
23.9 | 257. | N/A | Perry and Bardwell, 1925 | Based on data from 246. to 273. K.; AC |
23.5 | 267. | N/A | Perry and Bardwell, 1925 | Based on data from 246. to 273. K.; AC |
Entropy of vaporization
ΔvapS (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
92.58 | 252.0 | Ruehrwein and Giauque, 1939, 2 | P; DH |
Antoine Equation Parameters
log10(P) = A − (B / (T + C))
P = vapor pressure (bar)
T = temperature (K)
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Temperature (K) | A | B | C | Reference | Comment |
---|---|---|---|---|---|
252. to 391.3 | 4.51661 | 1041.518 | -21.288 | Stull, 1947 | Coefficents calculated by NIST from author's data. |
Enthalpy of sublimation
ΔsubH (kJ/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
33.0 | 224. | N/A | Stephenson and Malanowski, 1987 | Based on data from 202. to 239. K.; AC |
32.4 | 224. | N/A | Govers, 1975 | Based on data from 198. to 240. K. See also Perry and Bardwell, 1925.; AC |
33.6 | 204. | A | Stull, 1947 | Based on data from 177. to 230. K.; AC |
34.4 | 202. to 245. | CATH | Ruehrwein and Giauque, 1939, 2 | AC |
Enthalpy of fusion
ΔfusH (kJ/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
8.109 | 245.32 | Ruehrwein and Giauque, 1939, 2 | DH |
8.11 | 245.3 | Domalski and Hearing, 1996 | AC |
Entropy of fusion
ΔfusS (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
33.05 | 245.32 | Ruehrwein and Giauque, 1939, 2 | DH |
Henry's Law 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: Rolf Sander
Henry's Law constant (water solution)
kH(T) = k°H exp(d(ln(kH))/d(1/T) ((1/T) - 1/(298.15 K)))
k°H = Henry's law constant for solubility in water at 298.15 K (mol/(kg*bar))
d(ln(kH))/d(1/T) = Temperature dependence constant (K)
k°H (mol/(kg*bar)) | d(ln(kH))/d(1/T) (K) | Method | Reference | Comment |
---|---|---|---|---|
0.19 | Q | N/A | missing citation give several references for the Henry's law constants but don't assign them to specific species. Value at T = 293. K. |
Gas phase ion energetics data
Go To: Top, Gas phase thermochemistry data, Phase change data, Henry's Law 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 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
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
IE (evaluated) | 13.37 ± 0.01 | eV | N/A | N/A | L |
Quantity | Value | Units | Method | Reference | Comment |
Proton affinity (review) | 674.7 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 645.8 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Gas basicity at 298K
Gas basicity (review) (kJ/mol) | Reference | Comment |
---|---|---|
622.8 | Milligan, Fairley, et al., 1998 | T = 300K; ΔG =-RTln(kf/kr) from ratio of rate coefficients; MM |
621.7 | Milligan, Fairley, et al., 1998 | T = 300K; ΔG =-RTln(kf/kr) from ratio of rate coefficients; MM |
<642. | Milligan, Fairley, et al., 1998 | Irreversible PT from C2N2 to C2H5+; MM |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
13.5 ± 0.3 | EI | Smith, 1983 | LBLHLM |
13.36 ± 0.01 | PI | Baker and Turner, 1968 | RDSH |
13.374 ± 0.008 | PI | Dibeler and Liston, 1967 | RDSH |
13.5 | EI | Dorsch and Kallman, 1930 | RDSH |
13.51 | PE | Asbrink, Von Niessen, et al., 1980 | Vertical value; LLK |
Appearance energy determinations
Ion | AE (eV) | Other Products | Method | Reference | Comment |
---|---|---|---|---|---|
C+ | 22.5 | C+N2 | EI | Dorsch and Kallman, 1930 | RDSH |
CN+ | 20.9 ± 0.3 | CN | EI | Smith, 1983 | LBLHLM |
CN+ | 20.4 | CN | EI | Haney and Franklin, 1968 | RDSH |
CN+ | 20.42 ± 0.02 | CN | PI | Dibeler and Liston, 1967 | RDSH |
CN+ | 18. | CN | EI | Dorsch and Kallman, 1930 | RDSH |
C2+ | 18.0 ± 0.3 | N2 | EI | Smith, 1983 | LBLHLM |
C2+ | 17.46 ± 0.02 | N2 | PI | Dibeler and Liston, 1967 | RDSH |
C2+ | 17. | N2 | EI | Dorsch and Kallman, 1930 | RDSH |
C2N+ | 18.84 ± 0.05 | N | EI | Harland and McIntosh, 1985 | LBLHLM |
C2N+ | 19.5 ± 0.3 | N | EI | Smith, 1983 | LBLHLM |
C2N+ | 19.5 ± 0.1 | N | EI | Dibeler, Reese, et al., 1961 | RDSH |
Ion clustering data
Go To: Top, Gas phase thermochemistry data, Phase change data, Henry's Law 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 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)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 43.5 | kJ/mol | PHPMS | Speller and Meot-Ner (Mautner), 1985 | gas phase; Entropy change calculated or estimated, DG<, ΔrH< |
Quantity | Value | Units | Method | Reference | Comment |
ΔrS° | 96. | J/mol*K | N/A | Speller and Meot-Ner (Mautner), 1985 | gas phase; Entropy change calculated or estimated, DG<, ΔrH< |
Free energy of reaction
ΔrG° (kJ/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
13. | 315. | PHPMS | Speller and Meot-Ner (Mautner), 1985 | gas phase; Entropy change calculated or estimated, DG<, ΔrH< |
References
Go To: Top, Gas phase thermochemistry data, Phase change data, Henry's Law 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]
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]
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 HxCCN+ and HxCNC+ (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]
Notes
Go To: Top, Gas phase thermochemistry data, Phase change data, Henry's Law data, Gas phase ion energetics data, Ion clustering data, References
- Symbols used in this document:
AE Appearance energy IE (evaluated) Recommended ionization energy Ptriple Triple point pressure S°gas,1 bar Entropy of gas at standard conditions (1 bar) T Temperature Tboil Boiling point Ttriple Triple point temperature d(ln(kH))/d(1/T) Temperature dependence parameter for Henry's Law constant k°H Henry's Law constant at 298.15K 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
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