Ammonia - The NIST WebBook

Ammonia

• Formula: H3N
• Molecular weight: 17.0305
• IUPAC Standard InChI: InChI=1S/H3N/h1H3 Copy
• IUPAC Standard InChIKey: QGZKDVFQNNGYKY-UHFFFAOYSA-N Copy
• CAS Registry Number: 7664-41-7
• 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.
• Isotopologues:
  • Ammonia-d3
• Other names: Ammonia gas; Nitro-Sil; Spirit of Hartshorn; NH3; Ammonia, anhydrous; Anhydrous ammonia; Aromatic Ammonia, Vaporole
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Gas phase thermochemistry data
  • Phase change data
  • Reaction thermochemistry data: reactions 1 to 50, reactions 51 to 100, reactions 101 to 146
  • Henry's Law data
  • Ion clustering data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • Vibrational and/or electronic energy levels
  • Gas Chromatography
  • Fluid Properties
• Data at other public NIST sites:
  • Electron-Impact Ionization Cross Sections (on physics web site)
  • Gas Phase Kinetics Database
  • X-ray Photoelectron Spectroscopy Database, version 5.0
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Gas phase ion energetics data

Go To: Top, 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: B - John E. Bartmess LL - Sharon G. Lias and Joel F. Liebman 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 H3N+ (ion structure unspecified)

Quantity	Value	Units	Method	Reference	Comment
IE (evaluated)	10.070 ± 0.020	eV	N/A	N/A	L
Quantity	Value	Units	Method	Reference	Comment
Proton affinity (review)	853.6	kJ/mol	N/A	Hunter and Lias, 1998	HL
Quantity	Value	Units	Method	Reference	Comment
Gas basicity	819.0	kJ/mol	N/A	Hunter and Lias, 1998	HL

Ionization energy determinations

IE (eV)	Method	Reference	Comment
10.02	PI	Qi, Sheng, et al., 1995	T = 0K; LL
10.07 ± 0.01	PIPECO	Ruede, Troxler, et al., 1993	LL
10.186	TE	Reiser, Habenicht, et al., 1993	LL
10.069 ± 0.002	PI	Locht, Hottmann, et al., 1992	LL
10.072 ± 0.010	PI	Locht, Leyh, et al., 1991	LL
10.2985 ± 0.0001	TE	Habenicht, 1989	LL
10.45	EI	Baldwin, Loudon, et al., 1977	LLK
10.2	PE	Debies and Rabalais, 1975	LLK
10.18 ± 0.09	PE	Aue, Webb, et al., 1975	LLK
10.2	EI	Morrison and Traeger, 1973	LLK
10.15	PE	Potts and Price, 1972	LLK
10.18 ± 0.01	PE	Weiss and Lawrence, 1970	RDSH
14.94 ± 0.03	PE	Weiss and Lawrence, 1970	RDSH
10.14	PE	Branton, Frost, et al., 1969	RDSH
14.92	PE	Branton, Frost, et al., 1969	RDSH
10.16 ± 0.02	PI	Potapov, 1968	RDSH
10.17	PI	Chupka and Russell, 1968	RDSH
10.162 ± 0.008	PI	Dibeler, Walker, et al., 1966	RDSH
10.166	S	Watanabe and Sood, 1965	RDSH
10.16	PE	Al-Joboury and Turner, 1964	RDSH
15.02	PE	Al-Joboury and Turner, 1964	RDSH
10.15 ± 0.01	PI	Watanabe and Mottl, 1957	RDSH
10.82	PE	Baumgartel, Jochims, et al., 1989	Vertical value; LL
10.8	PE	Bieri, Asbrink, et al., 1982	Vertical value; LBLHLM
10.85	PE	Kimura, Katsumata, et al., 1981	Vertical value; LLK
11.3	PE	Campbell, Liesegang, et al., 1979	Vertical value; LLK
10.85	PE	Daamen and Oskam, 1978	Vertical value; LLK

Appearance energy determinations

Ion	AE (eV)	Other Products	Method	Reference	Comment
H+	18.57	H2N	PI	Qi, Sheng, et al., 1995	LL
HN+	28. ± 1.5	H2/2H	EI	Muller and Schulz, 1990	LL
HN+	16.9 ± 0.1	H2	EI	Locht, Servais, et al., 1988	LL
HN+	17.2	H2	EI	Morrison and Traeger, 1973	LLK
NH+	17.1 ± 0.1	H2	EI	Reed and Snedden, 1959	RDSH
H2N+	15.75	H	PI	Qi, Sheng, et al., 1995	LL
H2N+	15.60 ± 0.02	H	PIPECO	Ruede, Troxler, et al., 1993	LL
H2N+	15.75	H	PI	Locht, Hottmann, et al., 1992	LL
H2N+	15.76 ± 0.05	H	PI	Locht, Servais, et al., 1988	LL
H2N+	15.76 ± 0.05	H	EI	Locht, Servais, et al., 1988	LL
H2N+	15.5	H	PIPECO	Powis, 1981	LLK
H2N+	15.87 ± 0.13	H	DER	Powis, 1981	LLK
H2N+	15.768 ± 0.004	H	PI	McCulloh, 1976	LLK
H2N+	15.0	H	EI	Morrison and Traeger, 1973	LLK
NH2+	15.73 ± 0.02	H	PI	Dibeler, Walker, et al., 1966	RDSH
NH2+	16.0 ± 0.1	H	EI	Foner and Hudson, 1958	RDSH
N+	≤22.5	H2+H	EI	Morrison and Traeger, 1973	LLK
N+	22.6 ± 0.1	H2+H	EI	Reed and Snedden, 1959	RDSH

De-protonation reactions

H2N- + =

By formula: H2N- + H+ = H3N

Quantity	Value	Units	Method	Reference	Comment
ΔrH°	1688.0 ± 1.2	kJ/mol	D-EA	Wickham-Jones, Ervin, et al., 1989	gas phase; B
ΔrH°	1688.5 ± 3.3	kJ/mol	G+TS	MacKay, Hemsworth, et al., 1976	gas phase; B
ΔrH°	1683.2	kJ/mol	N/A	Check, Faust, et al., 2001	gas phase; HCrO3(t); ; ΔS(EA)=6.6; B
Quantity	Value	Units	Method	Reference	Comment
ΔrG°	1656.8 ± 1.6	kJ/mol	H-TS	Wickham-Jones, Ervin, et al., 1989	gas phase; B
ΔrG°	1657.3 ± 2.9	kJ/mol	IMRE	MacKay, Hemsworth, et al., 1976	gas phase; B
ΔrG°	1654.4	kJ/mol	N/A	Check, Faust, et al., 2001	gas phase; HCrO3(t); ; ΔS(EA)=6.6; B

References

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]

Qi, Sheng, et al., 1995 Qi, F.; Sheng, L.; Zhang, Y.; Yu, S.; Li, W.-K., Experimental and theoretical study of the dissociation energies DO(H2N-H) and DO(H2N+-H) and other related quantities, Chem. Phys. Lett., 1995, 234, 450. [all data]

Ruede, Troxler, et al., 1993 Ruede, R.; Troxler, H.; Beglinger, C.; Jungen, M., The dissociation energies of the positive ions NH3+, NF3+, PH3+, PF3+ and PCl3+, Chem. Phys. Lett., 1993, 203, 477. [all data]

Reiser, Habenicht, et al., 1993 Reiser, G.; Habenicht, W.; Muller-Dethlefs, K., Zero kinetic energy (ZEKE) photoelectron spectroscopy of ammonia by nonresonant two-photon ionization from the neutral ground state, J. Chem. Phys., 1993, 98, 8462. [all data]

Locht, Hottmann, et al., 1992 Locht, R.; Hottmann, K.; Hagenow, G.; Denzer, W.; Baumgartel, H., The threhold-photoelectron spectrum of NH3, Chem. Phys. Lett., 1992, 190, 124. [all data]

Locht, Leyh, et al., 1991 Locht, R.; Leyh, B.; Denzer, W.; Hagenow, G.; Baumgartel, H., The photoionization of ammonia revisited. The vibrational autoionization of NH3 and its three isotopomers in the 10-12 eV photon energy range, Chem. Phys., 1991, 155, 407. [all data]

Habenicht, 1989 Habenicht, W., [Title unavailable], Ph.D. Thesis, Technische Universitat Munchen, 1989. [all data]

Baldwin, Loudon, et al., 1977 Baldwin, M.A.; Loudon, A.G.; Webb, K.S.; Cardnell, P.C., Charge location and fragmentation under electron impact. V-The ionization potentials of (methylated) phosphoramides, guanidines, formamides, acetamides, ureas and thioureas, Org. Mass Spectrom., 1977, 12, 279. [all data]

Debies and Rabalais, 1975 Debies, T.P.; Rabalais, J.W., Calculated photoionization cross-sections and angular distributions for the isoelectronic series Ne, HF, H2O, NH3, and CH4, J. Am. Chem. Soc., 1975, 97, 487. [all data]

Aue, Webb, et al., 1975 Aue, D.H.; Webb, H.M.; Bowers, M.T., Photoelectron spectrum and gas-phase basicity of manxine. Evidence for a planar bridgehead nitrogen, J. Am. Chem. Soc., 1975, 97, 4136. [all data]

Morrison and Traeger, 1973 Morrison, J.D.; Traeger, J.C., Ionization and dissociation by electron impact. II. NH3 and PH3, Int. J. Mass Spectrom. Ion Phys., 1973, 11, 277. [all data]

Potts and Price, 1972 Potts, A.W.; Price, W.C., Photoelectron spectra and valence shell orbital structures of groups V VI hydrides, Proc. R. Soc. London A:, 1972, 326, 181. [all data]

Weiss and Lawrence, 1970 Weiss, M.J.; Lawrence, G.M., Photoelectron spectroscopy of NH3 and ND3 using molecular beams, J. Chem. Phys., 1970, 53, 214. [all data]

Branton, Frost, et al., 1969 Branton, G.R.; Frost, D.C.; Herring, F.G.; McDowell, C.A.; Stenhouse, I.A., The ionization potentials of ammonia and ammonia-d3, measured by photoelectron spectroscopy, and an INDO calculation of these values, Chem. Phys. Lett., 1969, 3, 581. [all data]

Potapov, 1968 Potapov, V.K., Mechanism of ionic-molecular reactions, Dokl. Akad. Nauk SSSR, 1968, 183, 386, In original 843. [all data]

Chupka and Russell, 1968 Chupka, W.A.; Russell, M.E., Ion-molecule reactions of NH3+ by photoionization, J. Chem. Phys., 1968, 48, 1527. [all data]

Dibeler, Walker, et al., 1966 Dibeler, V.H.; Walker, J.A.; Rosenstock, H.M., Mass spectrometric study of photoionization. V.Water and ammonia, J.Res. NBS, 1966, 70A, 459. [all data]

Watanabe and Sood, 1965 Watanabe, K.; Sood, S.P., Absorption and photoionization coefficients of NH3 in the 580-1650 A region, Sci. Light (Tokyo), 1965, 14, 36. [all data]

Al-Joboury and Turner, 1964 Al-Joboury, M.I.; Turner, D.W., Molecular photoelectron spectroscopy. Part II. A summary of ionization potentials, J. Chem. Soc., 1964, 4434. [all data]

Watanabe and Mottl, 1957 Watanabe, K.; Mottl, J.R., Ionization potentials of ammonia and some amines, J. Chem. Phys., 1957, 26, 1773. [all data]

Baumgartel, Jochims, et al., 1989 Baumgartel, H.; Jochims, H.-W.; Ruhl, E.; Bock, H.; Dammel, R.; Minkwitz, J.; Nass, R., Photoelectron and photoionization mass spectra of the fluoramines NH3-nFn1, Inorg. Chem., 1989, 28, 943. [all data]

Bieri, Asbrink, et al., 1982 Bieri, G.; Asbrink, L.; Von Niessen, W., 30.4-nm He(II) photoelectron spectra of organic molecules, J. Electron Spectrosc. Relat. Phenom., 1982, 27, 129. [all data]

Kimura, Katsumata, et al., 1981 Kimura, K.; Katsumata, S.; Achiba, Y.; Yamazaki, T.; Iwata, S., Ionization energies, Ab initio assignments, and valence electronic structure for 200 molecules in Handbook of HeI Photoelectron Spectra of Fundamental Organic Compounds, Japan Scientific Soc. Press, Tokyo, 1981. [all data]

Campbell, Liesegang, et al., 1979 Campbell, M.J.; Liesegang, J.; Riley, J.D.; Leckey, R.C.G.; Jenkin, J.G.; Poole, R.T., The electronic structure of the valence bands of solid NH3 and H2O studied by ultraviolet photoelectron spectroscopy, J. Electron Spectrosc. Relat. Phenom., 1979, 15, 83. [all data]

Daamen and Oskam, 1978 Daamen, H.; Oskam, A., Bonding properties of some monosubstituted chromium and tungsten hexacarbonyls M(CO)5L (L=amine, substituted pyridine, azine), Inorg. Chim. Acta, 1978, 26, 81. [all data]

Muller and Schulz, 1990 Muller, U.; Schulz, G., Electron-impact dissociation of ammonia; formation of NH+ ions in excited states, Chem. Phys. Lett., 1990, 170, 401. [all data]

Locht, Servais, et al., 1988 Locht, R.; Servais, C.; Ligot, M.; Derwa, F.; Momigny, J., The dissociative electroionization of ammonia and ammonia-d3. I. The NH+ and NH2+ dissociation channels, Chem. Phys., 1988, 123, 443. [all data]

Reed and Snedden, 1959 Reed, R.I.; Snedden, W., The ionisation potential of NH, J. Chem. Soc., 1959, 4132. [all data]

Powis, 1981 Powis, I., Influence of angular momentum in the dissociation of NH3+, J. Chem. Soc. Faraday Trans. 2, 1981, 77, 1433. [all data]

McCulloh, 1976 McCulloh, K.E., Energetics and mechanisms of fragment ion formation in the photoionization of normal and deuterated water and ammonia, Int. J. Mass Spectrom. Ion Phys., 1976, 21, 333. [all data]

Foner and Hudson, 1958 Foner, S.N.; Hudson, R.L., Mass spectrometric detection of triazene and tetrazene and studies of the free radicals NH2, and N2H3, J. Chem. Phys., 1958, 29, 442. [all data]

Wickham-Jones, Ervin, et al., 1989 Wickham-Jones, C.T.; Ervin, K.M.; Ellison, G.B.; Lineberger, W.C., NH2 Electron Affinity, J. Chem. Phys., 1989, 91, 4, 2762, https://doi.org/10.1063/1.456994 . [all data]

MacKay, Hemsworth, et al., 1976 MacKay, G.J.; Hemsworth, R.S.; Bohme, D.K., Absolute gas-phase acidities of CH3NH2, C2H5NH2, (CH3)2NH, and (CH3)3N, Can. J. Chem., 1976, 54, 1624. [all data]

Check, Faust, et al., 2001 Check, C.E.; Faust, T.O.; Bailey, J.M.; Wright, B.J.; Gilbert, T.M.; Sunderlin, L.S., Addition of Polarization and Diffuse Functions to the LANL2DZ Basis Set for P-Block Elements, J. Phys. Chem. A,, 2001, 105, 34, 8111, https://doi.org/10.1021/jp011945l . [all data]

Notes

Go To: Top, Gas phase ion energetics data, References

• Symbols used in this document:

  AE	Appearance energy
  IE (evaluated)	Recommended ionization energy
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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