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 thermochemistry data
  • Phase change data
  • Reaction thermochemistry data (reactions 1 to 50)
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • Vibrational and/or electronic energy levels
  • References
  • Notes
• Other data available:
  • Reaction thermochemistry data: reactions 51 to 100, reactions 101 to 146
  • Henry's Law data
  • Gas phase ion energetics data
  • Ion clustering data
  • 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
• Options:
  • Switch to calorie-based units

Data at NIST subscription sites:

• NIST / TRC Web Thermo Tables, "lite" edition (thermophysical and thermochemical data)
• 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, 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.

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.

Phase change data

Go To: Top, Gas 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:
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos

Enthalpy 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

Reaction thermochemistry data

Go To: Top, Gas 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
B - John E. Bartmess
RCD - Robert C. Dunbar

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.

Reactions 1 to 50

( • 3) +  = ( • 4)

By formula: (H₄N⁺ • 3H₃N) + H₃N = (H₄N⁺ • 4H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

Free energy of reaction

( • 2) +  = ( • 3)

By formula: (H₄N⁺ • 2H₃N) + H₃N = (H₄N⁺ • 3H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

Free energy of reaction

( • ) +  = ( • 2)

By formula: (H₄N⁺ • H₃N) + H₃N = (H₄N⁺ • 2H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

Free energy of reaction

 +  = ( • )

By formula: H₄N⁺ + H₃N = (H₄N⁺ • H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

Free energy of reaction

 +  = ( • )

By formula: Cl^- + H₃N = (Cl^- • H₃N)

Bond type: Hydrogen bond (negative ion to hydride)

( • 4) +  = ( • 5)

By formula: (H₄N⁺ • 4H₃N) + H₃N = (H₄N⁺ • 5H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

 +  = ( • )

By formula: Li⁺ + H₃N = (Li⁺ • H₃N)

( • ) +  = ( • 2)

By formula: (Na⁺ • H₃N) + H₃N = (Na⁺ • 2H₃N)

H₂N^- +  =

By formula: H₂N^- + H⁺ = H₃N

C₄H₉⁺ +  = (C₄H₉⁺ • )

By formula: C₄H₉⁺ + H₃N = (C₄H₉⁺ • H₃N)

 +  = ( • )

By formula: Na⁺ + H₃N = (Na⁺ • H₃N)

Free energy of reaction

C₃H₉Sn⁺ +  = (C₃H₉Sn⁺ • )

By formula: C₃H₉Sn⁺ + H₃N = (C₃H₉Sn⁺ • H₃N)

Free energy of reaction

( • 3 • ) +  = ( • 4 • )

By formula: (H₄N⁺ • 3CHN • H₃N) + CHN = (H₄N⁺ • 4CHN • H₃N)

Free energy of reaction

 +  = ( • )

By formula: I^- + H₃N = (I^- • H₃N)

Bond type: Hydrogen bond (negative ion to hydride)

( •  • 2) +  = ( • 2 • 2)

By formula: (H₄N⁺ • H₃N • 2CHN) + H₃N = (H₄N⁺ • 2H₃N • 2CHN)

Free energy of reaction

( •  • 2) +  = ( • 2 • 2)

By formula: (H₄N⁺ • CHN • 2H₃N) + CHN = (H₄N⁺ • 2CHN • 2H₃N)

Free energy of reaction

( • ) +  = ( •  • )

By formula: (H₄N⁺ • CHN) + H₃N = (H₄N⁺ • H₃N • CHN)

Free energy of reaction

 +  = ( • )

By formula: Br^- + H₃N = (Br^- • H₃N)

Bond type: Hydrogen bond (negative ion to hydride)

( • 5) +  = ( • 6)

By formula: (H₄N⁺ • 5H₃N) + H₃N = (H₄N⁺ • 6H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

 +  = ( • )

By formula: K⁺ + H₃N = (K⁺ • H₃N)

( • 2) +  = ( •  • 2)

By formula: (H₄N⁺ • 2H₃N) + CHN = (H₄N⁺ • CHN • 2H₃N)

( •  • 2) +  = ( • 2 • 2)

By formula: (H₄N⁺ • H₃N • 2H₂O) + H₃N = (H₄N⁺ • 2H₃N • 2H₂O)

Bond type: Hydrogen bond (positive ion to hydride)

( •  • 2) +  = ( • 2 • 2)

By formula: (H₄N⁺ • H₂O • 2H₃N) + H₂O = (H₄N⁺ • 2H₂O • 2H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

(C₆H₁₅O₃⁺ • ) +  = (C₆H₁₅O₃⁺ •  • )

By formula: (C₆H₁₅O₃⁺ • H₃N) + C₆H₁₄O₃ = (C₆H₁₅O₃⁺ • C₆H₁₄O₃ • H₃N)

Bond type: Hydrogen bonds between protonated and neutral organics

( • 2 • ) +  = ( • 3 • )

By formula: (H₄N⁺ • 2H₃N • H₂O) + H₃N = (H₄N⁺ • 3H₃N • H₂O)

Bond type: Hydrogen bond (positive ion to hydride)

( • 2 • ) +  = ( • 3 • )

By formula: (H₄N⁺ • 2H₂O • H₃N) + H₂O = (H₄N⁺ • 3H₂O • H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

( •  • ) +  = ( • 2 • )

By formula: (H₄N⁺ • H₃N • H₂O) + H₃N = (H₄N⁺ • 2H₃N • H₂O)

Bond type: Hydrogen bond (positive ion to hydride)

( •  • ) +  = ( • 2 • )

By formula: (H₄N⁺ • H₂O • H₃N) + H₂O = (H₄N⁺ • 2H₂O • H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

( • 2) +  = ( •  • 2)

By formula: (H₄N⁺ • 2H₃N) + H₂O = (H₄N⁺ • H₂O • 2H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

( • 2) +  = ( •  • 2)

By formula: (H₄N⁺ • 2H₂O) + H₃N = (H₄N⁺ • H₃N • 2H₂O)

Bond type: Hydrogen bond (positive ion to hydride)

( • 3) +  = ( •  • 3)

By formula: (H₄N⁺ • 3H₃N) + H₂O = (H₄N⁺ • H₂O • 3H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

( • 3) +  = ( •  • 3)

By formula: (H₄N⁺ • 3H₂O) + H₃N = (H₄N⁺ • H₃N • 3H₂O)

Bond type: Hydrogen bond (positive ion to hydride)

( • ) +  = ( •  • )

By formula: (H₄N⁺ • H₃N) + H₂O = (H₄N⁺ • H₂O • H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

( • ) +  = ( •  • )

By formula: (H₄N⁺ • H₂O) + H₃N = (H₄N⁺ • H₃N • H₂O)

Bond type: Hydrogen bond (positive ion to hydride)

( • ) +  = ( •  • )

By formula: (H₄N⁺ • C₄H₁₀O₂) + H₃N = (H₄N⁺ • H₃N • C₄H₁₀O₂)

Bond type: Hydrogen bond (positive ion to hydride)

 +  = ( • )

By formula: H^- + H₃N = (H^- • H₃N)

( • 2) +  = ( • 3)

By formula: (Cu⁺ • 2H₃N) + H₃N = (Cu⁺ • 3H₃N)

( • 3) +  = ( • 4)

By formula: (Cu⁺ • 3H₃N) + H₃N = (Cu⁺ • 4H₃N)

( • 2) +  = ( • 3)

By formula: (Pb⁺ • 2H₃N) + H₃N = (Pb⁺ • 3H₃N)

( • 3) +  = ( • 4)

By formula: (Pb⁺ • 3H₃N) + H₃N = (Pb⁺ • 4H₃N)

( • ) +  = ( • 2)

By formula: (Pb⁺ • H₃N) + H₃N = (Pb⁺ • 2H₃N)

C₂H₈N⁺ +  = (C₂H₈N⁺ • )

By formula: C₂H₈N⁺ + H₃N = (C₂H₈N⁺ • H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

C₆H₁₅O₃⁺ +  = (C₆H₁₅O₃⁺ • )

By formula: C₆H₁₅O₃⁺ + H₃N = (C₆H₁₅O₃⁺ • H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

CH₆N⁺ +  = (CH₆N⁺ • )

By formula: CH₆N⁺ + H₃N = (CH₆N⁺ • H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

 +  = ( • )

By formula: Pb⁺ + H₃N = (Pb⁺ • H₃N)

( • ) +  = ( • 2)

By formula: (H^- • H₃N) + H₃N = (H^- • 2H₃N)

(H₂N^- • ) +  = (H₂N^- • 2)

By formula: (H₂N^- • H₃N) + H₃N = (H₂N^- • 2H₃N)

( • 2 • ) +  = ( • 3 • )

By formula: (H₄N⁺ • 2CHN • H₃N) + CHN = (H₄N⁺ • 3CHN • H₃N)

( •  • ) +  = ( • 2 • )

By formula: (H₄N⁺ • CHN • H₃N) + CHN = (H₄N⁺ • 2CHN • H₃N)

( • 2 • ) +  = ( • 3 • )

By formula: (H₄N⁺ • 2H₃N • C₂H₃N) + H₃N = (H₄N⁺ • 3H₃N • C₂H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

IR Spectrum

Go To: Top, Gas 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 (50 mmHg DILUTED TO A TOTAL PRESSURE OF 600 mmHg WITH N2); DOW KBr FOREPRISM; DIGITIZED BY NIST FROM HARD COPY (FROM TWO SEGMENTS); 4 cm^-1 resolution

Data compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director

• gas

Mass spectrum (electron ionization)

Go To: Top, Gas 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, 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:   C_3ν     Symmetry Number σ = 3

Source: Shimanouchi, 1972

Notes

References

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, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Cox, Wagman, et al., 1984
Cox, J.D.; Wagman, D.D.; Medvedev, V.A., CODATA Key Values for Thermodynamics, Hemisphere Publishing Corp., New York, 1984, 1. [all data]

Chase, 1998
Chase, M.W., Jr., NIST-JANAF Themochemical Tables, Fourth Edition, J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951. [all data]

Timmermans, 1921
Timmermans, J., The Freezing Points of Organic Substances IV. New Exp. Determinations, Bull. Soc. Chim. Belg., 1921, 30, 62. [all data]

Fonseca and Lobo, 1989
Fonseca, I.M.A.; Lobo, L.Q., Thermodynamics of liquid mixtures of xenon and methyl fluoride, Fluid Phase Equilib., 1989, 47, 249. [all data]

Brunner, 1988
Brunner, E., Fluid Mixtures at High Pressures VI. Phase Separation and Critical Phenomena in 18 (n-Alkane + Ammonia) and 4 (n-Alkane _ Methanol) Mixtures, J. Chem. Thermodyn., 1988, 20, 273. [all data]

Hentze, 1977
Hentze, G., Critical temperature measurement of liquids by means of differential thermal analysis, Thermochim. Acta, 1977, 20, 27-30. [all data]

Zander and Thomas, 1979
Zander, Manfred; Thomas, Wilhelm, Some thermodynamic properties of liquid ammonia: PVT data, vapor pressure, and critical temperature, J. Chem. Eng. Data, 1979, 24, 1, 1-2, https://doi.org/10.1021/je60080a003 . [all data]

Overstreet and Giauque, 1937
Overstreet, Roy; Giauque, W.F., Ammonia. The Heat Capacity and Vapor Pressure of Solid and Liquid. Heat of Vaporization. The Entropy Values from Thermal and Spectroscopic Data, J. Am. Chem. Soc., 1937, 59, 2, 254-259, https://doi.org/10.1021/ja01281a008 . [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]

Fehsenfeld and Ferguson, 1973
Fehsenfeld, F.C.; Ferguson, E.E., Thermal Energy Positive Ion Reactions in a Wet Atmosphere Containing Ammonia, J. Chem. Phys., 1973, 59, 12, 6272, https://doi.org/10.1063/1.1680006 . [all data]

Puckett and Teague, 1971
Puckett, L.J.; Teague, M.W., Ion-Molecule Reactions in NO - NH3 Gas Mixtures, J. Chem. Phys., 1971, 54, 11, 4860, https://doi.org/10.1063/1.1674763 . [all data]

Tang and Castleman, 1975
Tang, I.N.; Castleman, A.W., Gas - Phase Solvation of the Ammonium Ion in Ammonia, J. Chem. Phys., 1975, 62, 11, 4576, https://doi.org/10.1063/1.430331 . [all data]

Arshadi and Futrell, 1974
Arshadi, M.R.; Futrell, J.H., Studies in High - Pressure Mass Spectrometry. V. Thermodynamics of Solvation Reactions. NH4+ - NH3, J. Phys. Chem., 1974, 78, 15, 1482, https://doi.org/10.1021/j100608a008 . [all data]

Long and Franklin, 1973
Long, J.W.; Franklin, J.L., Ion-Cluster Reactions in a Drift Tube Ion Source, Int. J. Mass Spectrom. Ion Phys, 1973, 12, 5, 403, https://doi.org/10.1016/0020-7381(73)80025-7 . [all data]

Searles and Kebarle, 1968
Searles, S.K.; Kebarle, P., Ion-Solvent-Molecule Interactions in the Gas Phase. Enthalpies and Entropies for the Reactions NH4+(NH3)(n-1) + NH3 = NH4+(NH3)n, J. Phys. Chem., 1968, 72, 2, 742, https://doi.org/10.1021/j100848a061 . [all data]

Payzant, Cunningham, et al., 1973
Payzant, J.D.; Cunningham, A.J.; Kebarle, P., Gas - Phase Solvation of Ammonium Ion by NH3 and H2O and Stabilities of Mixed Clusters NH4+(NH3)n(H2O)w, Can. J. Chem., 1973, 51, 19, 3242, https://doi.org/10.1139/v73-485 . [all data]

Wincel, 1972
Wincel, H., Ion-Molecule Reactions in Ammonia at High Pressures, Int. J. Mass Spectrom. Ion Phys., 1972, 9, 3, 267, https://doi.org/10.1016/0020-7381(72)80053-6 . [all data]

Tschurl and Boesl, 2008
Tschurl, M.; Boesl, U., IR-photodissociation and photodetachment spectroscopy of Cl-center dot(NH3)(x) (IR : x=1-4, PD : x=1), Chem. Phys. Lett., 2008, 456, 4-6, 150-155, https://doi.org/10.1016/j.cplett.2008.03.041 . [all data]

Evans, Keesee, et al., 1987
Evans, D.H.; Keesee, R.G.; Castleman Jr., The Association of Ammonia with Halide Ions in the Gas Phase, J. Chem. Phys., 1987, 86, 5, 2927, https://doi.org/10.1063/1.452043 . [all data]

Markovich, Chesnovsky, et al., 1993
Markovich, G.; Chesnovsky, O.; Kaldor, U., Charge Transfer Excitations in the Photoelectron Spectrum of Cl-NH3: Experiment and calculation, J. Chem. Phys, 1993, https://doi.org/10.1063/1.465913 . [all data]

Larson and McMahon, 1984
Larson, J.W.; McMahon, T.B., Hydrogen bonding in gas phase anions. An experimental investigation of the interaction between chloride ion and bronsted acids from ICR chloride exchange equilibria, J. Am. Chem. Soc., 1984, 106, 517. [all data]

Larson and McMahon, 1984, 2
Larson, J.W.; McMahon, T.B., Gas phase negative ion chemistry of alkylchloroformates, Can. J. Chem., 1984, 62, 675. [all data]

Wei, Tzeng, et al., 1990
Wei, S.; Tzeng, W.B.; Castleman, A.W., Kinetic Energy Release Measurements of Ammonia Cluster Ions During Metastable Decomposition and Determination of Cluster Ion Binding Energies, J. Chem. Phys., 1990, 92, 1, 332, https://doi.org/10.1063/1.458434 . [all data]

Kamke, Herrmann, et al., 1988
Kamke, W.; Herrmann, R.; Wang, Z.; Hertel, I.V., On the Photoionization and Fragmentation of Ammonia Clusters using TPEPICO, Z. Phys. D., 1988, 10, 4, 491, https://doi.org/10.1007/BF01425768 . [all data]

Hogg, Haynes, et al., 1966
Hogg, A.M.; Haynes, R.M.; Kebarle, P., Ion-Solvent Molecule Interactions Studied in the Gas Phase. Heats and Entropies of Individual Steps. NH4+.(n-1)NH3 = NH4+.nNH3, J. Am. Chem. Soc., 1966, 88, 1, 28, https://doi.org/10.1021/ja00953a006 . [all data]

Woodin and Beauchamp, 1978
Woodin, R.L.; Beauchamp, J.L., Bonding of Li+ to Lewis Bases in the Gas Phase. Reversals in Methyl Substituent Effects for Different Reference Acids, J. Am. Chem. Soc., 1978, 100, 2, 501, https://doi.org/10.1021/ja00470a024 . [all data]

Dzidic and Kebarle, 1970
Dzidic, I.; Kebarle, P., Hydration of the Alkali Ions in the Gas Phase. Enthalpies and Entropies of Reactions M+(H2O)n-1 + H2O = M+(H2O)n, J. Phys. Chem., 1970, 74, 7, 1466, https://doi.org/10.1021/j100702a013 . [all data]

Staley and Beauchamp, 1975
Staley, R.H.; Beauchamp, J.L., Intrinsic Acid - Base Properties of Molecules. Binding Energies of Li+ to pi - and n - Donor Bases, J. Am. Chem. Soc., 1975, 97, 20, 5920, https://doi.org/10.1021/ja00853a050 . [all data]

Castleman, Holland, et al., 1978
Castleman, A.W.; Holland, P.M.; Lindsay, D.M.; Peterson, K.I., The Properties of Clusters in the Gas Phase. 2. Ammonia about Metal Ions, J. Am. Chem. Soc., 1978, 100, 19, 6039, https://doi.org/10.1021/ja00487a011 . [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]

Meot-Ner (Mautner) and Sieck, 1991
Meot-Ner (Mautner), M.; Sieck, L.W., Proton affinity ladders from variable-temperature equilibrium measurements. 1. A reevaluation of the upper proton affinity range, J. Am. Chem. Soc., 1991, 113, 12, 4448, https://doi.org/10.1021/ja00012a012 . [all data]

Szulejko and McMahon, 1991
Szulejko, J.E.; McMahon, T.B., A Pulsed Electron Beam, Variable Temperature, High Pressure Mass Spectrometric Reevaluation of the Proton Affinity Difference Between 2-Methylpropene and Ammonia, Int. J. Mass Spectrom. Ion Proc., 1991, 109, 279, https://doi.org/10.1016/0168-1176(91)85109-Y . [all data]

Meot-Ner (Mautner) and Sieck, 1990
Meot-Ner (Mautner), M.; Sieck, L.W., Ion Thermochemistry at High Temperatures. 1. Thermochemistry of the Ammonium Ion from Variable - Temperature Equilibrium Measurements. Proton Transfer, Association, and Decomposition Reactions in Ammonia, Isobutene, and t-Butylamine, J. Phys. Chem., 1990, 94, 19, 7730, https://doi.org/10.1021/j100382a076 . [all data]

Amicangelo and Armentrout, 2001
Amicangelo, J.C.; Armentrout, P.B., Relative and Absolute Bond Dissociation Energies of Sodium Cation Complexes Determined Using Competitive Collision-Induced Dissociation Experiments, Int. J. Mass Spectrom., 2001, 212, 1-3, 301, https://doi.org/10.1016/S1387-3806(01)00494-8 . [all data]

Armentrout and Rodgers, 2000
Armentrout, P.B.; Rodgers, M.T., An Absolute Sodium Cation Affinity Scale: Threshold Collision-Induced Dissociation Experiments and ab Initio Theory, J. Phys. Chem A, 2000, 104, 11, 2238, https://doi.org/10.1021/jp991716n . [all data]

Hoyau, Norrman, et al., 1999
Hoyau, S.; Norrman, K.; McMahon, T.B.; Ohanessian, G., A Quantitative Basis for a Scale of Na+ Affinities of Organic and Small Biological Molecules in the Gas Phase, J. Am. Chem. Soc., 1999, 121, 38, 8864, https://doi.org/10.1021/ja9841198 . [all data]

McMahon and Ohanessian, 2000
McMahon, T.B.; Ohanessian, G., An Experimental and Ab Initio Study of the Nature of the Binding in Gas-Phase Complexes of Sodium Ions, Chem. Eur. J., 2000, 6, 16, 2931, https://doi.org/10.1002/1521-3765(20000818)6:16<2931::AID-CHEM2931>3.0.CO;2-7 . [all data]

Stone and Splinter, 1984
Stone, J.A.; Splinter, D.E., A high-pressure mass spectrometric study of the binding of (CH₃)₃Sn⁺ to lewis bases in the gas phase, Int. J. Mass Spectrom. Ion Processes, 1984, 59, 169. [all data]

Deakyne, Knuth, et al., 1994
Deakyne, C.A.; Knuth, D.M.; Speller, C.V.; Meot-Ner (Mautner), M.; Sieck, L.W., Filling of Solvent Shells about Ions. Part 3. Isomeric Clusters of (HCN)n(NH3)mH+, J. Mol. Structure (Theochem), 1994, 307, 217, https://doi.org/10.1016/0166-1280(94)80130-4 . [all data]

Caldwell, Masucci, et al., 1989
Caldwell, G.W.; Masucci, J.A.; Ikonomou, M.G., Negative Ion Chemical Ionization Mass Spectrometry - Binding of Molecules to Bromide and Iodide Anions, Org. Mass Spectrom., 1989, 24, 1, 8, https://doi.org/10.1002/oms.1210240103 . [all data]

Castleman, 1978
Castleman, A.W., The Properties of Clusters in the Gas Phase: Ammonia about Bi+, Rb+, and K+, Chem. Phys. Lett., 1978, 53, 3, 560, https://doi.org/10.1016/0009-2614(78)80069-4 . [all data]

Davidson and Kebarle, 1976
Davidson, W.R.; Kebarle, P., Binding Energies and Stabilities of Potassium Ion Complexes from Studies of Gas Phase Ion Equilibria K+ + M = K+.M, J. Am. Chem. Soc., 1976, 98, 20, 6133, https://doi.org/10.1021/ja00436a011 . [all data]

Meot-Ner (Mautner), Sieck, et al., 1996
Meot-Ner (Mautner), M.; Sieck, L.W.; Liebman, J.F.; Scheiner, S., Complexing of the Ammonium Ion by Polyethers. Comparative Complexing Thermochemistry of Ammonium, Hydronium, and Alkali Cations, J. Phys. Chem., 1996, 100, 16, 6445, https://doi.org/10.1021/jp9514943 . [all data]

Snodgrass, Coe, et al., 1995
Snodgrass, J.T.; Coe, J.V.; Freidhoff, C.B.; Mchugh, K.M.; Arnold, S.T.; Bowen, K.H., Negative ion photoelectron spectroscopy of NH2-(NH3)1 and NH2-(NH3)2: Gas phase basicities of partially solvated anions, J. Phys. Chem., 1995, 99, 24, 9675, https://doi.org/10.1021/j100024a006 . [all data]

Coe, Snodgrass, et al., 1985
Coe, J.V.; Snodgrass, J.T.; Friedhoff, C.B.; McHugh, K.M.; Bowen, K.H., Negative ion photoelectron spectroscopy of the negative ion H-(NH₃), J. Chem. Phys., 1985, 83, 3169. [all data]

Walter and Armentrout, 1998
Walter, D.; Armentrout, P.B., Periodic Trends in Chemical Reactivity: Reactions of Sc+, Y+, La+, and Lu+ with H2, D2 and HD, J. Am. Chem. Soc., 1998, 120, 13, 3176, https://doi.org/10.1021/ja973202c . [all data]

Holland and Castleman, 1982
Holland, P.M.; Castleman, A.W., The Thermochemical Properties of Gas - Phase Transition Metal Ion Complexes, J. Chem. Phys., 1982, 76, 8, 4195, https://doi.org/10.1063/1.443497 . [all data]

Guo and Castleman, 1991
Guo, B.C.; Castleman, A.W., The Clustering Reactions of Na+ and Pb+ with Several Important Ligands, Zeit. Phys. D., 1991, 19, 1-4, 397, https://doi.org/10.1007/BF01448337 . [all data]

Yamdagni and Kebarle, 1974
Yamdagni, R.; Kebarle, P., The hydrogen bond energies in ClHCl- and Cl-(HCl)n, Can. J. Chem., 1974, 52, 2449. [all data]

Snodgrass, Coe, et al., 1989
Snodgrass, J.T.; Coe, J.V.; Freidhoff, C.B.; McHugh, K.M.; Bowen, K.H., Photoelectron Spectroscopy of the Negative Cluster Ions, NH₂^-(NH₃)n=1,2, J. Chem. Phys., 1989, 92, xxxx. [all data]

Tzeng, Wei, et al., 1991
Tzeng, W.B.; Wei, S.; Castleman, A.W., Stability, Structure and Binding - Energies of Solvated Cluster Ions - Ammonia Acetonitrile and Ammonia Acetaldehyde Systems, J. Phys. Chem., 1991, 95, 15, 5757, https://doi.org/10.1021/j100168a011 . [all data]

Shimanouchi, 1972
Shimanouchi, T., Tables of Molecular Vibrational Frequencies Consolidated Volume I, National Bureau of Standards, 1972, 1-160. [all data]

Notes

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

• Symbols used in this document:
  

  Pc	Critical pressure
  Ptriple	Triple point pressure
  S°gas,1 bar	Entropy of gas at standard conditions (1 bar)
  T	Temperature
  Tc	Critical temperature
  Tfus	Fusion (melting) point
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  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

• 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.