Hydrogen cyanide

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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:
B - John E. Bartmess
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

View reactions leading to CHN+ (ion structure unspecified)

Quantity Value Units Method Reference Comment
IE (evaluated)13.60 ± 0.01eVN/AN/AL
Quantity Value Units Method Reference Comment
Proton affinity (review)712.9kJ/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity681.6kJ/molN/AHunter and Lias, 1998HL

Electron affinity determinations

EA (eV) Method Reference Comment
0.00156N/AArd, Garrett, et al., 2009B
>1.00171EIAETsuda, Yokohata, et al., 1971From CH3CN; G3MP2B3 calculations indicate that the anion is unbound by ca. 1 eV. Possibly C2H3- instead.; B

Ionization energy determinations

IE (eV) Method Reference Comment
13.71EILageot, 1972LLK
13.59 ± 0.01PIDibeler and Liston, 1968RDSH
13.60 ± 0.01PEBaker and Turner, 1968RDSH
13.73 ± 0.09EIVarsel, Morrell, et al., 1960RDSH
13.7 ± 0.1EIKusch, Hustrulid, et al., 1937RDSH
13.61PEKreile, Schweig, et al., 1982Vertical value; LBLHLM
13.607 ± 0.002PEFridh and Asbrink, 1975Vertical value; LLK
13.60PEPotts and Williams, 1974Vertical value; LLK
13.61 ± 0.01PEFrost, Lee, et al., 1973Vertical value; LLK

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
C+23.8 ± 0.5?EIKusch, Hustrulid, et al., 1937RDSH
CH+21.8 ± 0.5NEIKusch, Hustrulid, et al., 1937RDSH
CN+19.43 ± 0.01HPIBerkowitz, Chupka, et al., 1969RDSH
CN+19.40 ± 0.02HPIDibeler and Liston, 1968RDSH
CN+20.1 ± 0.2HEIKusch, Hustrulid, et al., 1937RDSH
H+15.18 ± 0.02CN-PIBerkowitz, Chupka, et al., 1969RDSH
H+19.00 ± 0.01CNPIBerkowitz, Chupka, et al., 1969RDSH
NH+24.9 ± 0.5CEIKusch, Hustrulid, et al., 1937RDSH
N+25.6 ± 0.5CHEIKusch, Hustrulid, et al., 1937RDSH

De-protonation reactions

CN- + Hydrogen cation = Hydrogen cyanide

By formula: CN- + H+ = CHN

Quantity Value Units Method Reference Comment
Δr1464. ± 4.2kJ/molCIDTAkin and Ervin, 2006gas phase; B
Δr1466.5 ± 0.71kJ/molD-EABradforth, Kim, et al., 1993gas phase; B
Δr1469. ± 8.8kJ/molG+TSBartmess, Scott, et al., 1979gas phase; value altered from reference due to change in acidity scale; B
Quantity Value Units Method Reference Comment
Δr1433. ± 4.6kJ/molH-TSAkin and Ervin, 2006gas phase; B
Δr1435.8 ± 1.1kJ/molH-TSBradforth, Kim, et al., 1993gas phase; B
Δr1438. ± 8.4kJ/molIMREBartmess, Scott, et al., 1979gas phase; value altered from reference due to change in acidity scale; B


Go To: Top, 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.

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]

Ard, Garrett, et al., 2009
Ard, S.; Garrett, W.R.; Compton, R.N.; Adamowicz, L.; Stepanian, S.G., Rotational states of dipole-bound anions of hydrogen cyanide., Chem. Phys. Lett., 2009, 473, 4-6, 223, https://doi.org/10.1016/j.cplett.2009.04.007 . [all data]

Tsuda, Yokohata, et al., 1971
Tsuda, S.; Yokohata, A.; Umaba, T., Measurement of negative ions formed by electron impact. VIII. Ionization efficiency curves of negative ions from methyl and ethyl cyanides, Bull. Chem. Soc. Jpn., 1971, 44, 1486. [all data]

Lageot, 1972
Lageot, C., Etude des etats excites de l'ion HCN+, J. Chim. Phys. Phys.-Chim. Biol., 1972, 68, 214. [all data]

Dibeler and Liston, 1968
Dibeler, V.H.; Liston, S.K., Mass-spectrometric study of photoionization. IX. Hydrogen cyanide and acetonitrile, J. Chem. Phys., 1968, 48, 4765. [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]

Varsel, Morrell, et al., 1960
Varsel, C.J.; Morrell, F.A.; Resnik, F.E.; Powell, W.A., Qualitative and quantitative analysis of organic compounds. Use of low-voltage mass spectrometry, Anal. Chem., 1960, 32, 182. [all data]

Kusch, Hustrulid, et al., 1937
Kusch, P.; Hustrulid, A.; Tate, J.T., The dissociation of HCN, C2H2, C2N2 and C2H4 by electron impact, Phys. Rev., 1937, 52, 843. [all data]

Kreile, Schweig, et al., 1982
Kreile, J.; Schweig, A.; Thiel, W., Experimental and theoretical investigation of the photoionization of hydrogen cyanide, Chem. Phys. Lett., 1982, 87, 473. [all data]

Fridh and Asbrink, 1975
Fridh, C.; Asbrink, L., Photoelectron electron impact spectrum of HCN, J. Electron Spectrosc. Relat. Phenom., 1975, 7, 119. [all data]

Potts and Williams, 1974
Potts, A.W.; Williams, T.A., The observation of "forbidden" transitions in He II photoelectron spectra, J. Electron Spectrosc. Relat. Phenom., 1974, 3, 3. [all data]

Frost, Lee, et al., 1973
Frost, D.C.; Lee, S.T.; McDowell, C.A., The photoelectron spectrum of HCP and comments on the first photoelectron band of HCN, Chem. Phys. Lett., 1973, 23, 472. [all data]

Berkowitz, Chupka, et al., 1969
Berkowitz, J.; Chupka, W.A.; Walter, T.A., Photoionization of HCN: the electron affinity and heat of formation of CN, J. Chem. Phys., 1969, 50, 1497. [all data]

Akin and Ervin, 2006
Akin, F.A.; Ervin, K.M., Collision-induced dissociation of HS-(HCN): Unsymmetrical hydrogen bonding in a proton-bound dimer anion, J. Phys. Chem. A, 2006, 110, 4, 1342-1349, https://doi.org/10.1021/jp0540454 . [all data]

Bradforth, Kim, et al., 1993
Bradforth, S.E.; Kim, E.H.; Arnold, D.W.; Neumark, D.M., Photoelectron Spectroscopy of CN-, NCO-, and NCS-, J. Chem. Phys., 1993, 98, 2, 800, https://doi.org/10.1063/1.464244 . [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]


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