Cyanogen

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Gas phase thermochemistry data

Go To: Top, Condensed 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:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Quantity Value Units Method Reference Comment
Δfgas73.870kcal/molReviewChase, 1998Data last reviewed in March, 1961
Δfgas73.84 ± 0.43kcal/molCcbKnowlton and Prosen, 1951ALS
Δfgas62.9kcal/molCmMcMorris and Badger, 1933ALS
Δfgas73.30 ± 0.20kcal/molCcbWartenberg and Schutza, 1933Reanalyzed by Cox and Pilcher, 1970, Original value = 72.8 ± 0.2 kcal/mol; ALS
Quantity Value Units Method Reference Comment
Δcgas-261.94 ± 0.43kcal/molCcbKnowlton and Prosen, 1951ALS
Δcgas-251.4 ± 1.2kcal/molCmMcMorris and Badger, 1933ALS
Δcgas-261.40 ± 0.20kcal/molCcbWartenberg and Schutza, 1933Reanalyzed by Cox and Pilcher, 1970, Original value = -261.3 ± 0.2 kcal/mol; ALS
Quantity Value Units Method Reference Comment
gas,1 bar57.737cal/mol*KReviewChase, 1998Data 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 (cal/mol*K)
    H° = standard enthalpy (kcal/mol)
    S° = standard entropy (cal/mol*K)
    t = temperature (K) / 1000.

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Temperature (K) 298. to 1300.1300. to 6000.
A 12.3549019.83990
B 8.7938600.528003
C -2.978380-0.100319
D 0.1677350.006615
E -0.102472-2.224821
F 69.4778063.10569
G 69.6196075.45870
H 73.8701073.87010
ReferenceChase, 1998Chase, 1998
Comment Data last reviewed in March, 1961 Data last reviewed in March, 1961

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: Eugene S. Domalski and Elizabeth D. Hearing

Quantity Value Units Method Reference Comment
liquid33.181cal/mol*KN/ARuehrwein and Giauque, 1939 

Constant pressure heat capacity of liquid

Cp,liquid (cal/mol*K) Temperature (K) Reference Comment
25.270255.Ruehrwein and Giauque, 1939T = 15 to 252 K.

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:
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

NH4+ + Cyanogen = (NH4+ • Cyanogen)

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

Quantity Value Units Method Reference Comment
Δr10.4kcal/molPHPMSSpeller and Meot-Ner (Mautner), 1985gas phase; Entropy change calculated or estimated, DG<, ΔrH<; M
Quantity Value Units Method Reference Comment
Δr23.cal/mol*KN/ASpeller and Meot-Ner (Mautner), 1985gas phase; Entropy change calculated or estimated, DG<, ΔrH<; M

Free energy of reaction

ΔrG° (kcal/mol) T (K) Method Reference Comment
3.2315.PHPMSSpeller and Meot-Ner (Mautner), 1985gas phase; Entropy change calculated or estimated, DG<, ΔrH<; M

Cyanogen + Ethane, hexafluoro- = 2Acetonitrile, trifluoro-

By formula: C2N2 + C2F6 = 2C2F3N

Quantity Value Units Method Reference Comment
Δr10.54 ± 0.14kcal/molEqkWalker, Sinke, et al., 1970gas phase; ALS

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:
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 ± 0.01eVN/AN/AL
Quantity Value Units Method Reference Comment
Proton affinity (review)161.3kcal/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity154.3kcal/molN/AHunter and Lias, 1998HL

Gas basicity at 298K

Gas basicity (review) (kcal/mol) Reference Comment
148.9Milligan, Fairley, et al., 1998T = 300K; ΔG =-RTln(kf/kr) from ratio of rate coefficients; MM
148.6Milligan, Fairley, et al., 1998T = 300K; ΔG =-RTln(kf/kr) from ratio of rate coefficients; MM
<153.Milligan, Fairley, et al., 1998Irreversible PT from C2N2 to C2H5+; MM

Ionization energy determinations

IE (eV) Method Reference Comment
13.5 ± 0.3EISmith, 1983LBLHLM
13.36 ± 0.01PIBaker and Turner, 1968RDSH
13.374 ± 0.008PIDibeler and Liston, 1967RDSH
13.5EIDorsch and Kallman, 1930RDSH
13.51PEAsbrink, Von Niessen, et al., 1980Vertical value; LLK

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
C+22.5C+N2EIDorsch and Kallman, 1930RDSH
CN+20.9 ± 0.3CNEISmith, 1983LBLHLM
CN+20.4CNEIHaney and Franklin, 1968RDSH
CN+20.42 ± 0.02CNPIDibeler and Liston, 1967RDSH
CN+18.CNEIDorsch and Kallman, 1930RDSH
C2+18.0 ± 0.3N2EISmith, 1983LBLHLM
C2+17.46 ± 0.02N2PIDibeler and Liston, 1967RDSH
C2+17.N2EIDorsch and Kallman, 1930RDSH
C2N+18.84 ± 0.05NEIHarland and McIntosh, 1985LBLHLM
C2N+19.5 ± 0.3NEISmith, 1983LBLHLM
C2N+19.5 ± 0.1NEIDibeler, Reese, et al., 1961RDSH

References

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

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]

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]

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]


Notes

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