Ammonia

Formula: H₃N
Molecular weight: 17.0305
IUPAC Standard InChI: InChI=1S/H3N/h1H3
IUPAC Standard InChIKey: QGZKDVFQNNGYKY-UHFFFAOYSA-N
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:
Other data available:
- Reaction thermochemistry data: reactions 51 to 100, reactions 101 to 146
- Henry's Law data
- Mass spectrum (electron ionization)
- Vibrational and/or electronic energy levels
- Fluid Properties
Data at other public NIST sites:
Options:
- Switch to SI units

Data at NIST subscription sites:

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, Gas phase ion energetics data, Ion clustering data, IR Spectrum, Gas Chromatography, References, Notes

Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_gas	-10.98 ± 0.084	kcal/mol	Review	Cox, Wagman, et al., 1984	CODATA Review value
Δ_fH°_gas	-10.97	kcal/mol	Review	Chase, 1998	Data last reviewed in June, 1977
Quantity	Value	Units	Method	Reference	Comment
S°_{gas,1 bar}	46.07 ± 0.01	cal/mol*K	Review	Cox, Wagman, et al., 1984	CODATA Review value
S°_{gas,1 bar}	46.073	cal/mol*K	Review	Chase, 1998	Data last reviewed in June, 1977

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 (cal/mol*K)
H° = standard enthalpy (kcal/mol)
S° = standard entropy (cal/mol*K)
t = temperature (K) / 1000.

View plot Requires a JavaScript / HTML 5 canvas capable browser.

View table.

Temperature (K)	298. to 1400.	1400. to 6000.
A	4.779071	12.43410
B	11.89560	4.418741
C	-3.674950	-0.899887
D	0.459170	0.059403
E	0.045214	-2.977532
F	-12.74060	-20.44430
G	48.72349	53.49001
H	-10.96990	-10.96990
Reference	Chase, 1998	Chase, 1998
Comment	Data last reviewed in June, 1977	Data last reviewed in June, 1977

Phase change data

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, IR Spectrum, Gas Chromatography, References, Notes

Data compiled as indicated in comments:
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos

Quantity	Value	Units	Method	Reference	Comment
T_fus	194.95	K	N/A	Timmermans, 1921	Uncertainty assigned by TRC = 0.3 K; TRC
Quantity	Value	Units	Method	Reference	Comment
P_triple	0.05981	atm	N/A	Fonseca and Lobo, 1989	Uncertainty assigned by TRC = 0.00005 atm; TRC
Quantity	Value	Units	Method	Reference	Comment
T_c	405.4	K	N/A	Brunner, 1988	Uncertainty assigned by TRC = 0.1 K; TRC
T_c	405.6	K	N/A	Hentze, 1977	Uncertainty assigned by TRC = 5. K; TRC
Quantity	Value	Units	Method	Reference	Comment
P_c	111.52	atm	N/A	Brunner, 1988	Uncertainty assigned by TRC = 0.05 atm; TRC

Enthalpy of vaporization

Δ_vapH (kcal/mol)	Temperature (K)	Method	Reference	Comment
5.43	308.	N/A	Zander and Thomas, 1979	Based on data from 293. to 392. K.; AC
5.62	239.	N/A	Overstreet and Giauque, 1937	Based on data from 199. to 241. K.; AC
5.59	239.	C	Overstreet and Giauque, 1937	AC

Antoine Equation Parameters

log₁₀(P) = A − (B / (T + C))
P = vapor pressure (atm)
T = temperature (K)

View plot Requires a JavaScript / HTML 5 canvas capable browser.

Temperature (K)	A	B	C	Reference	Comment
164.0 to 239.6	3.18186	506.713	-80.78	Stull, 1947	Coefficents calculated by NIST from author's data.
239.6 to 371.5	4.86315	1113.928	-10.409	Stull, 1947	Coefficents calculated by NIST from author's data.

Enthalpy of sublimation

Δ_subH (kcal/mol)	Temperature (K)	Reference	Comment
7.46	177. to 195.	Overstreet and Giauque, 1937	AC

In addition to the Thermodynamics Research Center (TRC) data available from this site, much more physical and chemical property data is available from the following TRC products:

Reaction thermochemistry data

Go To: Top, Gas phase thermochemistry data, Phase change data, Gas phase ion energetics data, Ion clustering data, IR Spectrum, Gas Chromatography, References, Notes

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 Ammonia ) + Ammonia = ( • 4 Ammonia )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	12.2 ± 0.9	kcal/mol	AVG	N/A	Average of 5 out of 10 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	28. ± 2.	cal/mol*K	AVG	N/A	Average of 3 out of 7 values; Individual data points

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
3.4	296.	FA	Fehsenfeld and Ferguson, 1973	gas phase; M

( • 2 Ammonia ) + Ammonia = ( • 3 Ammonia )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	13. ± 5.	kcal/mol	AVG	N/A	Average of 6 out of 9 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25. ± 1.	cal/mol*K	AVG	N/A	Average of 4 out of 7 values; Individual data points

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
6.5	296.	FA	Fehsenfeld and Ferguson, 1973	gas phase; M
6.4	296.	SAMS	Puckett and Teague, 1971	gas phase; M

( • Ammonia ) + Ammonia = ( • 2 Ammonia )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	17. ± 1.	kcal/mol	AVG	N/A	Average of 5 out of 8 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.9	cal/mol*K	HPMS	Tang and Castleman, 1975	gas phase; M
Δ_rS°	23.7	cal/mol*K	PHPMS	Arshadi and Futrell, 1974	gas phase; M
Δ_rS°	24.8	cal/mol*K	DT	Long and Franklin, 1973	gas phase; M
Δ_rS°	26.8	cal/mol*K	PHPMS	Searles and Kebarle, 1968	gas phase; M
Δ_rS°	22.9	cal/mol*K	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; typographical error in Δ_rH; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
9.7	296.	FA	Fehsenfeld and Ferguson, 1973	gas phase; DG>; M
10.1	296.	SAMS	Puckett and Teague, 1971	gas phase; M
5.5	400.	HPMS	Wincel, 1972	gas phase; M

+ Ammonia = ( • Ammonia )

By formula: H₄N⁺ + H₃N = (H₄N⁺ • H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	26. ± 2.	kcal/mol	AVG	N/A	Average of 4 out of 9 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	26. ± 3.	cal/mol*K	AVG	N/A	Average of 4 out of 6 values; Individual data points

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
6.3	400.	HPMS	Wincel, 1972	gas phase; M

+ Ammonia = ( • Ammonia )

By formula: Cl^- + H₃N = (Cl^- • H₃N)

Bond type: Hydrogen bond (negative ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	<7.30 ± 0.40	kcal/mol	N/A	Tschurl and Boesl, 2008	gas phase; B
Δ_rH°	8.20 ± 0.10	kcal/mol	TDAs	Evans, Keesee, et al., 1987	gas phase; B,M
Δ_rH°	8.9 ± 1.2	kcal/mol	N/A	Markovich, Chesnovsky, et al., 1993	gas phase; B
Δ_rH°	10.5 ± 4.0	kcal/mol	IMRE	Larson and McMahon, 1984	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	15.4	cal/mol*K	HPMS	Evans, Keesee, et al., 1987	gas phase; M
Δ_rS°	19.9	cal/mol*K	N/A	Larson and McMahon, 1984	gas phase; switching reaction(Cl-)CH3F, Entropy change calculated or estimated; Larson and McMahon, 1984, 2; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	3.60 ± 0.20	kcal/mol	TDAs	Evans, Keesee, et al., 1987	gas phase; B
Δ_rG°	4.5 ± 2.0	kcal/mol	IMRE	Larson and McMahon, 1984	gas phase; B,M

( • 4 Ammonia ) + Ammonia = ( • 5 Ammonia )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.0	kcal/mol	PHPMS	Arshadi and Futrell, 1974	gas phase; M
Δ_rH°	7.5	kcal/mol	PHPMS	Searles and Kebarle, 1968	gas phase; M
Δ_rH°	7.	kcal/mol	MKER	Wei, Tzeng, et al., 1990	gas phase; from graph; M
Δ_rH°	2.8	kcal/mol	TPEPICO	Kamke, Herrmann, et al., 1988	gas phase; M
Δ_rH°	9.6	kcal/mol	DT	Long and Franklin, 1973	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	21.5	cal/mol*K	PHPMS	Arshadi and Futrell, 1974	gas phase; M
Δ_rS°	25.	cal/mol*K	PHPMS	Searles and Kebarle, 1968	gas phase; M
Δ_rS°	32.	cal/mol*K	DT	Long and Franklin, 1973	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	0.5	kcal/mol	HPMS	Hogg, Haynes, et al., 1966	gas phase; M

+ Ammonia = ( • Ammonia )

By formula: Li⁺ + H₃N = (Li⁺ • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	39.1	kcal/mol	ICR	Woodin and Beauchamp, 1978	gas phase; switching reaction(Li+)H2O, Entropy change calculated or estimated; Dzidic and Kebarle, 1970 interpolated; M
Δ_rH°	38.5	kcal/mol	ICR	Staley and Beauchamp, 1975	gas phase; switching reaction(Li+)H2O, from graph; Dzidic and Kebarle, 1970 extrapolated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.	cal/mol*K	N/A	Woodin and Beauchamp, 1978	gas phase; switching reaction(Li+)H2O, Entropy change calculated or estimated; Dzidic and Kebarle, 1970 interpolated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	32.1	kcal/mol	ICR	Woodin and Beauchamp, 1978	gas phase; switching reaction(Li+)H2O, Entropy change calculated or estimated; Dzidic and Kebarle, 1970 interpolated; M

( • Ammonia ) + Ammonia = ( • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	22. ± 1.	kcal/mol	AVG	N/A	Average of 6 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.1	cal/mol*K	HPMS	Castleman, Holland, et al., 1978	gas phase; M

H₂N^- + = Ammonia

By formula: H₂N^- + H⁺ = H₃N

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	403.44 ± 0.28	kcal/mol	D-EA	Wickham-Jones, Ervin, et al., 1989	gas phase; B
Δ_rH°	403.55 ± 0.80	kcal/mol	G+TS	MacKay, Hemsworth, et al., 1976	gas phase; B
Δ_rH°	402.30	kcal/mol	N/A	Check, Faust, et al., 2001	gas phase; HCrO3(t); ; ΔS(EA)=6.6; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	395.99 ± 0.38	kcal/mol	H-TS	Wickham-Jones, Ervin, et al., 1989	gas phase; B
Δ_rG°	396.10 ± 0.70	kcal/mol	IMRE	MacKay, Hemsworth, et al., 1976	gas phase; B
Δ_rG°	395.40	kcal/mol	N/A	Check, Faust, et al., 2001	gas phase; HCrO3(t); ; ΔS(EA)=6.6; B

C₄H₉⁺ + Ammonia = (C₄H₉⁺ • Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	46.8	kcal/mol	PHPMS	Meot-Ner (Mautner) and Sieck, 1991	gas phase; forms t-C4H9NH3+; M
Δ_rH°	45.3	kcal/mol	PHPMS	Szulejko and McMahon, 1991	gas phase; forms t-C4H9NH3+; M
Δ_rH°	46.5	kcal/mol	PHPMS	Meot-Ner (Mautner) and Sieck, 1990	gas phase; forms t-C4H9NH3+; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	43.7	cal/mol*K	PHPMS	Meot-Ner (Mautner) and Sieck, 1991	gas phase; forms t-C4H9NH3+; M
Δ_rS°	47.3	cal/mol*K	PHPMS	Szulejko and McMahon, 1991	gas phase; forms t-C4H9NH3+; M
Δ_rS°	44.0	cal/mol*K	PHPMS	Meot-Ner (Mautner) and Sieck, 1990	gas phase; forms t-C4H9NH3+; M

+ Ammonia = ( • Ammonia )

By formula: Na⁺ + H₃N = (Na⁺ • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	24.4 ± 1.3	kcal/mol	CIDC	Amicangelo and Armentrout, 2001	Anchor NH3=24.41; RCD
Δ_rH°	24.4 ± 1.3	kcal/mol	CIDT	Armentrout and Rodgers, 2000	RCD
Δ_rH°	25.6 ± 0.2	kcal/mol	HPMS	Hoyau, Norrman, et al., 1999	RCD
Δ_rH°	29.1	kcal/mol	HPMS	Castleman, Holland, et al., 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	21800.	cal/mol*K	HPMS	Hoyau, Norrman, et al., 1999	RCD
Δ_rS°	25.7	cal/mol*K	HPMS	Castleman, Holland, et al., 1978	gas phase; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
18.6	298.	IMRE	McMahon and Ohanessian, 2000	Anchor alanine=39.89; RCD

C₃H₉Sn⁺ + Ammonia = (C₃H₉Sn⁺ • Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	36.9	kcal/mol	PHPMS	Stone and Splinter, 1984	gas phase; switching reaction((CH3)3Sn+)CH3OH/NH3, Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	29.1	cal/mol*K	N/A	Stone and Splinter, 1984	gas phase; switching reaction((CH3)3Sn+)CH3OH/NH3, Entropy change calculated or estimated; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
21.6	525.	PHPMS	Stone and Splinter, 1984	gas phase; switching reaction((CH3)3Sn+)CH3OH/NH3, Entropy change calculated or estimated; M

( • 3 • Ammonia ) + = ( • 4 • Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.6	kcal/mol	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated, T = 392 in paper is error; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	20.	cal/mol*K	N/A	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated, T = 392 in paper is error; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
2.7	292.	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated, T = 392 in paper is error; M

+ Ammonia = ( • Ammonia )

By formula: I^- + H₃N = (I^- • H₃N)

Bond type: Hydrogen bond (negative ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.40 ± 0.30	kcal/mol	TDAs	Evans, Keesee, et al., 1987	gas phase; B,M
Δ_rH°	7.4 ± 1.0	kcal/mol	TDAs	Caldwell, Masucci, et al., 1989	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	20.9	cal/mol*K	HPMS	Evans, Keesee, et al., 1987	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	1.20 ± 0.60	kcal/mol	TDAs	Evans, Keesee, et al., 1987	gas phase; B

( • Ammonia • 2) + Ammonia = ( • 2 Ammonia • 2)

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	12.9	kcal/mol	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	20.	cal/mol*K	N/A	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
6.6	315.	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated; M

( • • 2 Ammonia ) + = ( • 2 • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	11.2	kcal/mol	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	20.	cal/mol*K	N/A	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
4.9	315.	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated; M

( • ) + Ammonia = ( • Ammonia • )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	18.8	kcal/mol	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	22.	cal/mol*K	N/A	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
9.4	429.	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated; M

+ Ammonia = ( • Ammonia )

By formula: Br^- + H₃N = (Br^- • H₃N)

Bond type: Hydrogen bond (negative ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.70 ± 0.10	kcal/mol	TDAs	Evans, Keesee, et al., 1987	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	19.1	cal/mol*K	HPMS	Evans, Keesee, et al., 1987	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	2.00 ± 0.20	kcal/mol	TDAs	Evans, Keesee, et al., 1987	gas phase; B

( • 5 Ammonia ) + Ammonia = ( • 6 Ammonia )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.5	kcal/mol	PHPMS	Arshadi and Futrell, 1974	gas phase; M
Δ_rH°	6.	kcal/mol	MKER	Wei, Tzeng, et al., 1990	gas phase; from graph; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	21.9	cal/mol*K	PHPMS	Arshadi and Futrell, 1974	gas phase; M

+ Ammonia = ( • Ammonia )

By formula: K⁺ + H₃N = (K⁺ • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	20.1	kcal/mol	HPMS	Castleman, 1978	gas phase; M
Δ_rH°	17.8	kcal/mol	HPMS	Davidson and Kebarle, 1976	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.0	cal/mol*K	HPMS	Castleman, 1978	gas phase; M
Δ_rS°	28.0	cal/mol*K	HPMS	Davidson and Kebarle, 1976	gas phase; M

( • 2 Ammonia ) + = ( • • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	13.4	kcal/mol	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	18.3	cal/mol*K	N/A	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated; M

( • Ammonia • 2) + Ammonia = ( • 2 Ammonia • 2)

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	15.7	kcal/mol	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	33.9	cal/mol*K	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M

( • • 2 Ammonia ) + = ( • 2 • 2 Ammonia )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	11.7	kcal/mol	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	27.8	cal/mol*K	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M

(C₆H₁₅O₃⁺ • Ammonia ) + = (C₆H₁₅O₃⁺ • • Ammonia )

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

Bond type: Hydrogen bonds between protonated and neutral organics

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	30.5	kcal/mol	PHPMS	Meot-Ner (Mautner), Sieck, et al., 1996	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	50.9	cal/mol*K	PHPMS	Meot-Ner (Mautner), Sieck, et al., 1996	gas phase; M

( • 2 Ammonia • ) + Ammonia = ( • 3 Ammonia • )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	15.0	kcal/mol	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	34.3	cal/mol*K	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M

( • 2 • Ammonia ) + = ( • 3 • Ammonia )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	12.2	kcal/mol	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	28.5	cal/mol*K	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M

( • Ammonia • ) + Ammonia = ( • 2 Ammonia • )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	17.1	kcal/mol	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	31.8	cal/mol*K	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M

( • • Ammonia ) + = ( • 2 • Ammonia )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	12.7	kcal/mol	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.0	cal/mol*K	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M

( • 2 Ammonia ) + = ( • • 2 Ammonia )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	12.4	kcal/mol	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	24.6	cal/mol*K	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M

( • 2) + Ammonia = ( • Ammonia • 2)

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	18.2	kcal/mol	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	30.3	cal/mol*K	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M

( • 3 Ammonia ) + = ( • • 3 Ammonia )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	11.7	kcal/mol	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	27.9	cal/mol*K	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M

( • 3) + Ammonia = ( • Ammonia • 3)

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	17.3	kcal/mol	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	35.1	cal/mol*K	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M

( • Ammonia ) + = ( • • Ammonia )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	12.9	kcal/mol	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	20.3	cal/mol*K	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M

( • ) + Ammonia = ( • Ammonia • )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	18.4	kcal/mol	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.0	cal/mol*K	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M

( • ) + Ammonia = ( • Ammonia • )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	14.0	kcal/mol	PHPMS	Meot-Ner (Mautner), Sieck, et al., 1996	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	19.4	cal/mol*K	PHPMS	Meot-Ner (Mautner), Sieck, et al., 1996	gas phase; M

+ Ammonia = ( • Ammonia )

By formula: H^- + H₃N = (H^- • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.10	kcal/mol	Est	Snodgrass, Coe, et al., 1995	gas phase; Stated electron affinity is the Vertical Detachment Energy; B
Δ_rH°	8.3	kcal/mol	PES	Coe, Snodgrass, et al., 1985	gas phase; Δ_rH<; M

( • 2 Ammonia ) + Ammonia = ( • 3 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	11.2 ± 1.4	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD
Δ_rH°	14.0	kcal/mol	HPMS	Holland and Castleman, 1982	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.8	cal/mol*K	HPMS	Holland and Castleman, 1982	gas phase; M

( • 3 Ammonia ) + Ammonia = ( • 4 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	10.0 ± 1.4	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD
Δ_rH°	12.8	kcal/mol	HPMS	Holland and Castleman, 1982	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	28.7	cal/mol*K	HPMS	Holland and Castleman, 1982	gas phase; M

( • 2 Ammonia ) + Ammonia = ( • 3 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	13.0	kcal/mol	HPMS	Guo and Castleman, 1991	gas phase; Δ_rS from graph; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	21.4	cal/mol*K	HPMS	Guo and Castleman, 1991	gas phase; Δ_rS from graph; M

( • 3 Ammonia ) + Ammonia = ( • 4 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	10.7	kcal/mol	HPMS	Guo and Castleman, 1991	gas phase; Δ_rS from graph; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	24.3	cal/mol*K	HPMS	Guo and Castleman, 1991	gas phase; Δ_rS from graph; M

( • Ammonia ) + Ammonia = ( • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	19.2	kcal/mol	HPMS	Guo and Castleman, 1991	gas phase; Δ_rS from graph; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	27.0	cal/mol*K	HPMS	Guo and Castleman, 1991	gas phase; Δ_rS from graph; M

C₂H₈N⁺ + Ammonia = (C₂H₈N⁺ • Ammonia )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	20.6	kcal/mol	PHPMS	Yamdagni and Kebarle, 1974	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	28.2	cal/mol*K	PHPMS	Yamdagni and Kebarle, 1974	gas phase; M

C₆H₁₅O₃⁺ + Ammonia = (C₆H₁₅O₃⁺ • Ammonia )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	30.4	kcal/mol	PHPMS	Meot-Ner (Mautner), Sieck, et al., 1996	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	27.9	cal/mol*K	PHPMS	Meot-Ner (Mautner), Sieck, et al., 1996	gas phase; M

CH₆N⁺ + Ammonia = (CH₆N⁺ • Ammonia )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	21.4	kcal/mol	PHPMS	Yamdagni and Kebarle, 1974	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	26.	cal/mol*K	PHPMS	Yamdagni and Kebarle, 1974	gas phase; M

+ Ammonia = ( • Ammonia )

By formula: Pb⁺ + H₃N = (Pb⁺ • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	28.3	kcal/mol	HPMS	Guo and Castleman, 1991	gas phase; Δ_rS from graph; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.6	cal/mol*K	HPMS	Guo and Castleman, 1991	gas phase; Δ_rS from graph; M

( • Ammonia ) + Ammonia = ( • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.10	kcal/mol	Est	Snodgrass, Coe, et al., 1995	gas phase; Affinity: shift in apparent EA from lesser-solvated ion. Ignores any neutral-neutral bond.; B

(H₂N^- • Ammonia ) + Ammonia = (H₂N^- • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	11.10	kcal/mol	Est	Snodgrass, Coe, et al., 1989	gas phase; Affinity: shift in apparent EA from lesser-solvated ion. Ignores any neutral-neutral bond.; B

( • 2 • Ammonia ) + = ( • 3 • Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	12.8	kcal/mol	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	24.1	cal/mol*K	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; M

( • • Ammonia ) + = ( • 2 • Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	12.2	kcal/mol	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	19.4	cal/mol*K	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; M

( • 2 Ammonia • ) + Ammonia = ( • 3 Ammonia • )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	13.6	kcal/mol	MKER	Tzeng, Wei, et al., 1991	gas phase; from graph; M

Gas phase ion energetics data

Go To: Top, Gas phase thermochemistry data, Phase change data, Reaction thermochemistry data, Ion clustering data, IR Spectrum, Gas Chromatography, References, Notes

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)	204.0	kcal/mol	N/A	Hunter and Lias, 1998	HL
Quantity	Value	Units	Method	Reference	Comment
Gas basicity	195.7	kcal/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^- + = Ammonia

By formula: H₂N^- + H⁺ = H₃N

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	403.44 ± 0.28	kcal/mol	D-EA	Wickham-Jones, Ervin, et al., 1989	gas phase; B
Δ_rH°	403.55 ± 0.80	kcal/mol	G+TS	MacKay, Hemsworth, et al., 1976	gas phase; B
Δ_rH°	402.30	kcal/mol	N/A	Check, Faust, et al., 2001	gas phase; HCrO3(t); ; ΔS(EA)=6.6; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	395.99 ± 0.38	kcal/mol	H-TS	Wickham-Jones, Ervin, et al., 1989	gas phase; B
Δ_rG°	396.10 ± 0.70	kcal/mol	IMRE	MacKay, Hemsworth, et al., 1976	gas phase; B
Δ_rG°	395.40	kcal/mol	N/A	Check, Faust, et al., 2001	gas phase; HCrO3(t); ; ΔS(EA)=6.6; B

Ion clustering data

Go To: Top, Gas phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, IR Spectrum, Gas Chromatography, References, Notes

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. Searches may be limited to ion clustering reactions. A general reaction search form is also available.

Clustering reactions

( • Ammonia ) + Ammonia = ( • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	36.9	kcal/mol	HPMS	Holland and Castleman, 1982	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	32.7	cal/mol*K	HPMS	Holland and Castleman, 1982	gas phase; M

( • 2 Ammonia ) + Ammonia = ( • 3 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	14.6	kcal/mol	HPMS	Holland and Castleman, 1982	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	24.6	cal/mol*K	HPMS	Holland and Castleman, 1982	gas phase; M

( • 3 Ammonia ) + Ammonia = ( • 4 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	13.0	kcal/mol	HPMS	Holland and Castleman, 1982	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	30.0	cal/mol*K	HPMS	Holland and Castleman, 1982	gas phase; M

( • 4 Ammonia ) + Ammonia = ( • 5 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	12.8	kcal/mol	HPMS	Holland and Castleman, 1982	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	34.1	cal/mol*K	HPMS	Holland and Castleman, 1982	gas phase; M

+ Ammonia = ( • Ammonia )

By formula: Bi⁺ + H₃N = (Bi⁺ • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	35.5	kcal/mol	HPMS	Castleman, 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	35.7	cal/mol*K	HPMS	Castleman, 1978	gas phase; M

( • Ammonia ) + Ammonia = ( • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	23.2	kcal/mol	HPMS	Castleman, 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	33.0	cal/mol*K	HPMS	Castleman, 1978	gas phase; M

( • 2 Ammonia ) + Ammonia = ( • 3 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	13.4	kcal/mol	HPMS	Castleman, 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	26.0	cal/mol*K	HPMS	Castleman, 1978	gas phase; M

+ Ammonia = ( • Ammonia )

By formula: Br^- + H₃N = (Br^- • H₃N)

Bond type: Hydrogen bond (negative ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.70 ± 0.10	kcal/mol	TDAs	Evans, Keesee, et al., 1987	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	19.1	cal/mol*K	HPMS	Evans, Keesee, et al., 1987	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	2.00 ± 0.20	kcal/mol	TDAs	Evans, Keesee, et al., 1987	gas phase; B

CH₆N⁺ + Ammonia = (CH₆N⁺ • Ammonia )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	21.4	kcal/mol	PHPMS	Yamdagni and Kebarle, 1974	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	26.	cal/mol*K	PHPMS	Yamdagni and Kebarle, 1974	gas phase; M

C₂H₈N⁺ + Ammonia = (C₂H₈N⁺ • Ammonia )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	20.6	kcal/mol	PHPMS	Yamdagni and Kebarle, 1974	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	28.2	cal/mol*K	PHPMS	Yamdagni and Kebarle, 1974	gas phase; M

C₃H₉Si⁺ + Ammonia = (C₃H₉Si⁺ • Ammonia )

By formula: C₃H₉Si⁺ + H₃N = (C₃H₉Si⁺ • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	46.5	kcal/mol	PHPMS	Li and Stone, 1990	gas phase; switching reaction((CH3)3Si+)CH3COOC2H5; Wojtyniak and Stone, 1986; M

C₃H₉Sn⁺ + Ammonia = (C₃H₉Sn⁺ • Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	36.9	kcal/mol	PHPMS	Stone and Splinter, 1984	gas phase; switching reaction((CH3)3Sn+)CH3OH/NH3, Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	29.1	cal/mol*K	N/A	Stone and Splinter, 1984	gas phase; switching reaction((CH3)3Sn+)CH3OH/NH3, Entropy change calculated or estimated; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
21.6	525.	PHPMS	Stone and Splinter, 1984	gas phase; switching reaction((CH3)3Sn+)CH3OH/NH3, Entropy change calculated or estimated; M

C₄H₉⁺ + Ammonia = (C₄H₉⁺ • Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	46.8	kcal/mol	PHPMS	Meot-Ner (Mautner) and Sieck, 1991	gas phase; forms t-C4H9NH3+; M
Δ_rH°	45.3	kcal/mol	PHPMS	Szulejko and McMahon, 1991	gas phase; forms t-C4H9NH3+; M
Δ_rH°	46.5	kcal/mol	PHPMS	Meot-Ner (Mautner) and Sieck, 1990	gas phase; forms t-C4H9NH3+; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	43.7	cal/mol*K	PHPMS	Meot-Ner (Mautner) and Sieck, 1991	gas phase; forms t-C4H9NH3+; M
Δ_rS°	47.3	cal/mol*K	PHPMS	Szulejko and McMahon, 1991	gas phase; forms t-C4H9NH3+; M
Δ_rS°	44.0	cal/mol*K	PHPMS	Meot-Ner (Mautner) and Sieck, 1990	gas phase; forms t-C4H9NH3+; M

C₅H₁₀NO₂⁺ + Ammonia = (C₅H₁₀NO₂⁺ • Ammonia )

By formula: C₅H₁₀NO₂⁺ + H₃N = (C₅H₁₀NO₂⁺ • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	20.6	kcal/mol	PHPMS	Meot-Ner and Field, 1974	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	28.9	cal/mol*K	PHPMS	Meot-Ner and Field, 1974	gas phase; M

C₅H₁₂NO₂⁺ + Ammonia = (C₅H₁₂NO₂⁺ • Ammonia )

By formula: C₅H₁₂NO₂⁺ + H₃N = (C₅H₁₂NO₂⁺ • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	20.9	kcal/mol	PHPMS	Meot-Ner and Field, 1974	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	28.8	cal/mol*K	PHPMS	Meot-Ner and Field, 1974	gas phase; M

C₆H₁₅O₃⁺ + Ammonia = (C₆H₁₅O₃⁺ • Ammonia )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	30.4	kcal/mol	PHPMS	Meot-Ner (Mautner), Sieck, et al., 1996	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	27.9	cal/mol*K	PHPMS	Meot-Ner (Mautner), Sieck, et al., 1996	gas phase; M

+ Ammonia = ( • Ammonia )

By formula: Cl^- + H₃N = (Cl^- • H₃N)

Bond type: Hydrogen bond (negative ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	<7.30 ± 0.40	kcal/mol	N/A	Tschurl and Boesl, 2008	gas phase; B
Δ_rH°	8.20 ± 0.10	kcal/mol	TDAs	Evans, Keesee, et al., 1987	gas phase; B,M
Δ_rH°	8.9 ± 1.2	kcal/mol	N/A	Markovich, Chesnovsky, et al., 1993	gas phase; B
Δ_rH°	10.5 ± 4.0	kcal/mol	IMRE	Larson and McMahon, 1984	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	15.4	cal/mol*K	HPMS	Evans, Keesee, et al., 1987	gas phase; M
Δ_rS°	19.9	cal/mol*K	N/A	Larson and McMahon, 1984	gas phase; switching reaction(Cl-)CH3F, Entropy change calculated or estimated; Larson and McMahon, 1984, 2; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	3.60 ± 0.20	kcal/mol	TDAs	Evans, Keesee, et al., 1987	gas phase; B
Δ_rG°	4.5 ± 2.0	kcal/mol	IMRE	Larson and McMahon, 1984	gas phase; B,M

+ Ammonia = ( • Ammonia )

By formula: Co⁺ + H₃N = (Co⁺ • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	52.1 ± 3.6	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD
Δ_rH°	58.8	kcal/mol	CID	Marinelli and Squires, 1989	gas phase; M

( • Ammonia ) + Ammonia = ( • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	59.3 ± 3.1	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD
Δ_rH°	61.1	kcal/mol	CID	Marinelli and Squires, 1989	gas phase; M

( • 2 Ammonia ) + Ammonia = ( • 3 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	15.3 ± 1.4	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD

( • 3 Ammonia ) + Ammonia = ( • 4 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	11.7 ± 1.4	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD

+ Ammonia = ( • Ammonia )

By formula: Cr⁺ + H₃N = (Cr⁺ • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	43.5 ± 2.4	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD
Δ_rH°	37.4	kcal/mol	CID	Marinelli and Squires, 1989	gas phase; M

( • Ammonia ) + Ammonia = ( • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	42.8 ± 2.2	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD
Δ_rH°	40.8	kcal/mol	CID	Marinelli and Squires, 1989	gas phase; M

( • 2 Ammonia ) + Ammonia = ( • 3 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	12.9 ± 1.4	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD

( • 3 Ammonia ) + Ammonia = ( • 4 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.2 ± 2.2	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD

+ Ammonia = ( • Ammonia )

By formula: Cu⁺ + H₃N = (Cu⁺ • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	56.6 ± 3.3	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD

( • Ammonia ) + Ammonia = ( • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	58.8 ± 2.4	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD

( • 2 Ammonia ) + Ammonia = ( • 3 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	11.2 ± 1.4	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD
Δ_rH°	14.0	kcal/mol	HPMS	Holland and Castleman, 1982	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.8	cal/mol*K	HPMS	Holland and Castleman, 1982	gas phase; M

( • 3 Ammonia ) + Ammonia = ( • 4 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	10.0 ± 1.4	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD
Δ_rH°	12.8	kcal/mol	HPMS	Holland and Castleman, 1982	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	28.7	cal/mol*K	HPMS	Holland and Castleman, 1982	gas phase; M

( • 4 Ammonia ) + Ammonia = ( • 5 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	12.8	kcal/mol	HPMS	Holland and Castleman, 1982	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	33.1	cal/mol*K	HPMS	Holland and Castleman, 1982	gas phase; M

+ Ammonia = ( • Ammonia )

By formula: F^- + H₃N = (F^- • H₃N)

Bond type: Hydrogen bond (negative ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	23.	kcal/mol	FA	Spears and Ferguson, 1973	gas phase; Δ_rH>; M

+ Ammonia = ( • Ammonia )

By formula: Fe⁺ + H₃N = (Fe⁺ • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	43.7 ± 2.9	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD
Δ_rH°	38.5	kcal/mol	CID	Marinelli and Squires, 1989	gas phase; M

( • Ammonia ) + Ammonia = ( • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	53.8 ± 2.9	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD
Δ_rH°	48.7	kcal/mol	CID	Marinelli and Squires, 1989	gas phase; M

( • 2 Ammonia ) + Ammonia = ( • 3 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	16.3 ± 3.1	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD

( • 3 Ammonia ) + Ammonia = ( • 4 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	10.0 ± 1.7	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD

+ Ammonia = ( • Ammonia )

By formula: H^- + H₃N = (H^- • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.10	kcal/mol	Est	Snodgrass, Coe, et al., 1995	gas phase; Stated electron affinity is the Vertical Detachment Energy; B
Δ_rH°	8.3	kcal/mol	PES	Coe, Snodgrass, et al., 1985	gas phase; Δ_rH<; M

( • Ammonia ) + Ammonia = ( • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.10	kcal/mol	Est	Snodgrass, Coe, et al., 1995	gas phase; Affinity: shift in apparent EA from lesser-solvated ion. Ignores any neutral-neutral bond.; B

HO^- + Ammonia = H₄NO^-

By formula: HO^- + H₃N = H₄NO^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	12.00	kcal/mol	N/A	Schwartz, Davico, et al., 2000	gas phase; Vertical Detachment Energy: 2.54±0.015 eV. Affinity is from difference in EAs; B

H₂N^- + Ammonia = (H₂N^- • Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	12.00	kcal/mol	PDis	Snodgrass, Coe, et al., 1989	gas phase; B

(H₂N^- • Ammonia ) + Ammonia = (H₂N^- • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	11.10	kcal/mol	Est	Snodgrass, Coe, et al., 1989	gas phase; Affinity: shift in apparent EA from lesser-solvated ion. Ignores any neutral-neutral bond.; B

H₃N⁺ + Ammonia = (H₃N⁺ • Ammonia )

By formula: H₃N⁺ + H₃N = (H₃N⁺ • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	23.1 ± 4.6	kcal/mol	EI	Stephan, Futrell, et al., 1982	gas phase; M
Δ_rH°	18.1	kcal/mol	PI	Ng, Trevor, et al., 1977	gas phase; M

(H₃N⁺ • Ammonia ) + Ammonia = (H₃N⁺ • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	9. ± 5.	kcal/mol	EI	Breen, Tzeng, et al., 1989	gas phase; M
Δ_rH°	9.2 ± 4.6	kcal/mol	EI	Stephan, Futrell, et al., 1982	gas phase; M

( • ) + Ammonia = ( • Ammonia • )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	18.8	kcal/mol	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	22.	cal/mol*K	N/A	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
9.4	429.	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated; M

( • ) + Ammonia = ( • Ammonia • )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	14.0	kcal/mol	PHPMS	Meot-Ner (Mautner), Sieck, et al., 1996	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	19.4	cal/mol*K	PHPMS	Meot-Ner (Mautner), Sieck, et al., 1996	gas phase; M

( • ) + Ammonia = ( • Ammonia • )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	18.4	kcal/mol	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.0	cal/mol*K	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M

( • 2) + Ammonia = ( • Ammonia • 2)

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	18.2	kcal/mol	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	30.3	cal/mol*K	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M

( • 3) + Ammonia = ( • Ammonia • 3)

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	17.3	kcal/mol	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	35.1	cal/mol*K	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M

+ Ammonia = ( • Ammonia )

By formula: H₄N⁺ + H₃N = (H₄N⁺ • H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	26. ± 2.	kcal/mol	AVG	N/A	Average of 4 out of 9 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	26. ± 3.	cal/mol*K	AVG	N/A	Average of 4 out of 6 values; Individual data points

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
6.3	400.	HPMS	Wincel, 1972	gas phase; M

( • Ammonia • 2) + Ammonia = ( • 2 Ammonia • 2)

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	12.9	kcal/mol	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	20.	cal/mol*K	N/A	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
6.6	315.	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated; M

( • Ammonia • ) + Ammonia = ( • 2 Ammonia • )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	15.5	kcal/mol	MKER	Tzeng, Wei, et al., 1991	gas phase; from graph; M

( • 2 Ammonia • ) + Ammonia = ( • 3 Ammonia • )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	13.6	kcal/mol	MKER	Tzeng, Wei, et al., 1991	gas phase; from graph; M

( • 3 Ammonia • ) + Ammonia = ( • 4 Ammonia • )

By formula: (H₄N⁺ • 3H₃N • C₂H₃N) + H₃N = (H₄N⁺ • 4H₃N • C₂H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.4	kcal/mol	MKER	Tzeng, Wei, et al., 1991	gas phase; from graph; M

( • 4 Ammonia • ) + Ammonia = ( • 5 Ammonia • )

By formula: (H₄N⁺ • 4H₃N • C₂H₃N) + H₃N = (H₄N⁺ • 5H₃N • C₂H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.9	kcal/mol	MKER	Tzeng, Wei, et al., 1991	gas phase; from graph; M

( • 5 Ammonia • ) + Ammonia = ( • 6 Ammonia • )

By formula: (H₄N⁺ • 5H₃N • C₂H₃N) + H₃N = (H₄N⁺ • 6H₃N • C₂H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.0	kcal/mol	MKER	Tzeng, Wei, et al., 1991	gas phase; from graph; M

( • 6 Ammonia • ) + Ammonia = ( • 7 Ammonia • )

By formula: (H₄N⁺ • 6H₃N • C₂H₃N) + H₃N = (H₄N⁺ • 7H₃N • C₂H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.5	kcal/mol	MKER	Tzeng, Wei, et al., 1991	gas phase; from graph; M

( • 7 Ammonia • ) + Ammonia = ( • 8 Ammonia • )

By formula: (H₄N⁺ • 7H₃N • C₂H₃N) + H₃N = (H₄N⁺ • 8H₃N • C₂H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.0	kcal/mol	MKER	Tzeng, Wei, et al., 1991	gas phase; from graph; M

( • 8 Ammonia • ) + Ammonia = ( • 9 Ammonia • )

By formula: (H₄N⁺ • 8H₃N • C₂H₃N) + H₃N = (H₄N⁺ • 9H₃N • C₂H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.5	kcal/mol	MKER	Tzeng, Wei, et al., 1991	gas phase; from graph; M

( • Ammonia • ) + Ammonia = ( • 2 Ammonia • )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	17.1	kcal/mol	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	31.8	cal/mol*K	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M

( • Ammonia • 2) + Ammonia = ( • 2 Ammonia • 2)

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	15.7	kcal/mol	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	33.9	cal/mol*K	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M

( • 2 Ammonia • ) + Ammonia = ( • 3 Ammonia • )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	15.0	kcal/mol	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	34.3	cal/mol*K	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; M

( • Ammonia ) + Ammonia = ( • 2 Ammonia )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	17. ± 1.	kcal/mol	AVG	N/A	Average of 5 out of 8 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.9	cal/mol*K	HPMS	Tang and Castleman, 1975	gas phase; M
Δ_rS°	23.7	cal/mol*K	PHPMS	Arshadi and Futrell, 1974	gas phase; M
Δ_rS°	24.8	cal/mol*K	DT	Long and Franklin, 1973	gas phase; M
Δ_rS°	26.8	cal/mol*K	PHPMS	Searles and Kebarle, 1968	gas phase; M
Δ_rS°	22.9	cal/mol*K	PHPMS	Payzant, Cunningham, et al., 1973	gas phase; typographical error in Δ_rH; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
9.7	296.	FA	Fehsenfeld and Ferguson, 1973	gas phase; DG>; M
10.1	296.	SAMS	Puckett and Teague, 1971	gas phase; M
5.5	400.	HPMS	Wincel, 1972	gas phase; M

( • 2 Ammonia ) + Ammonia = ( • 3 Ammonia )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	13. ± 5.	kcal/mol	AVG	N/A	Average of 6 out of 9 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25. ± 1.	cal/mol*K	AVG	N/A	Average of 4 out of 7 values; Individual data points

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
6.5	296.	FA	Fehsenfeld and Ferguson, 1973	gas phase; M
6.4	296.	SAMS	Puckett and Teague, 1971	gas phase; M

( • 3 Ammonia ) + Ammonia = ( • 4 Ammonia )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	12.2 ± 0.9	kcal/mol	AVG	N/A	Average of 5 out of 10 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	28. ± 2.	cal/mol*K	AVG	N/A	Average of 3 out of 7 values; Individual data points

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
3.4	296.	FA	Fehsenfeld and Ferguson, 1973	gas phase; M

( • 4 Ammonia ) + Ammonia = ( • 5 Ammonia )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.0	kcal/mol	PHPMS	Arshadi and Futrell, 1974	gas phase; M
Δ_rH°	7.5	kcal/mol	PHPMS	Searles and Kebarle, 1968	gas phase; M
Δ_rH°	7.	kcal/mol	MKER	Wei, Tzeng, et al., 1990	gas phase; from graph; M
Δ_rH°	2.8	kcal/mol	TPEPICO	Kamke, Herrmann, et al., 1988	gas phase; M
Δ_rH°	9.6	kcal/mol	DT	Long and Franklin, 1973	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	21.5	cal/mol*K	PHPMS	Arshadi and Futrell, 1974	gas phase; M
Δ_rS°	25.	cal/mol*K	PHPMS	Searles and Kebarle, 1968	gas phase; M
Δ_rS°	32.	cal/mol*K	DT	Long and Franklin, 1973	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	0.5	kcal/mol	HPMS	Hogg, Haynes, et al., 1966	gas phase; M

( • 5 Ammonia ) + Ammonia = ( • 6 Ammonia )

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

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.5	kcal/mol	PHPMS	Arshadi and Futrell, 1974	gas phase; M
Δ_rH°	6.	kcal/mol	MKER	Wei, Tzeng, et al., 1990	gas phase; from graph; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	21.9	cal/mol*K	PHPMS	Arshadi and Futrell, 1974	gas phase; M

( • 6 Ammonia ) + Ammonia = ( • 7 Ammonia )

By formula: (H₄N⁺ • 6H₃N) + H₃N = (H₄N⁺ • 7H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.	kcal/mol	MKER	Wei, Tzeng, et al., 1990	gas phase; from graph; M

( • 7 Ammonia ) + Ammonia = ( • 8 Ammonia )

By formula: (H₄N⁺ • 7H₃N) + H₃N = (H₄N⁺ • 8H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.	kcal/mol	MKER	Wei, Tzeng, et al., 1990	gas phase; from graph; M

( • 8 Ammonia ) + Ammonia = ( • 9 Ammonia )

By formula: (H₄N⁺ • 8H₃N) + H₃N = (H₄N⁺ • 9H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.	kcal/mol	MKER	Wei, Tzeng, et al., 1990	gas phase; from graph; M

( • 9 Ammonia ) + Ammonia = ( • 10 Ammonia )

By formula: (H₄N⁺ • 9H₃N) + H₃N = (H₄N⁺ • 10H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.	kcal/mol	MKER	Wei, Tzeng, et al., 1990	gas phase; from graph; M

( • 10 Ammonia ) + Ammonia = ( • 11 Ammonia )

By formula: (H₄N⁺ • 10H₃N) + H₃N = (H₄N⁺ • 11H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.	kcal/mol	MKER	Wei, Tzeng, et al., 1990	gas phase; from graph; M

( • 11 Ammonia ) + Ammonia = ( • 12 Ammonia )

By formula: (H₄N⁺ • 11H₃N) + H₃N = (H₄N⁺ • 12H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.	kcal/mol	MKER	Wei, Tzeng, et al., 1990	gas phase; from graph; M

( • 12 Ammonia ) + Ammonia = ( • 13 Ammonia )

By formula: (H₄N⁺ • 12H₃N) + H₃N = (H₄N⁺ • 13H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.	kcal/mol	MKER	Wei, Tzeng, et al., 1990	gas phase; from graph; M

( • 13 Ammonia ) + Ammonia = ( • 14 Ammonia )

By formula: (H₄N⁺ • 13H₃N) + H₃N = (H₄N⁺ • 14H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.	kcal/mol	MKER	Wei, Tzeng, et al., 1990	gas phase; from graph; M

( • 14 Ammonia ) + Ammonia = ( • 15 Ammonia )

By formula: (H₄N⁺ • 14H₃N) + H₃N = (H₄N⁺ • 15H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.	kcal/mol	MKER	Wei, Tzeng, et al., 1990	gas phase; from graph; M

( • 15 Ammonia ) + Ammonia = ( • 16 Ammonia )

By formula: (H₄N⁺ • 15H₃N) + H₃N = (H₄N⁺ • 16H₃N)

Bond type: Hydrogen bond (positive ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.	kcal/mol	MKER	Wei, Tzeng, et al., 1990	gas phase; from graph; M

+ Ammonia = ( • Ammonia )

By formula: I^- + H₃N = (I^- • H₃N)

Bond type: Hydrogen bond (negative ion to hydride)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.40 ± 0.30	kcal/mol	TDAs	Evans, Keesee, et al., 1987	gas phase; B,M
Δ_rH°	7.4 ± 1.0	kcal/mol	TDAs	Caldwell, Masucci, et al., 1989	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	20.9	cal/mol*K	HPMS	Evans, Keesee, et al., 1987	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	1.20 ± 0.60	kcal/mol	TDAs	Evans, Keesee, et al., 1987	gas phase; B

+ Ammonia = ( • Ammonia )

By formula: K⁺ + H₃N = (K⁺ • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	20.1	kcal/mol	HPMS	Castleman, 1978	gas phase; M
Δ_rH°	17.8	kcal/mol	HPMS	Davidson and Kebarle, 1976	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.0	cal/mol*K	HPMS	Castleman, 1978	gas phase; M
Δ_rS°	28.0	cal/mol*K	HPMS	Davidson and Kebarle, 1976	gas phase; M

( • Ammonia ) + Ammonia = ( • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	16.3	kcal/mol	HPMS	Castleman, 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	22.8	cal/mol*K	HPMS	Castleman, 1978	gas phase; M

( • 2 Ammonia ) + Ammonia = ( • 3 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	13.5	kcal/mol	HPMS	Castleman, 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	27.7	cal/mol*K	HPMS	Castleman, 1978	gas phase; M

( • 3 Ammonia ) + Ammonia = ( • 4 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	11.6	kcal/mol	HPMS	Castleman, 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.4	cal/mol*K	HPMS	Castleman, 1978	gas phase; M

+ Ammonia = ( • Ammonia )

By formula: Li⁺ + H₃N = (Li⁺ • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	39.1	kcal/mol	ICR	Woodin and Beauchamp, 1978	gas phase; switching reaction(Li+)H2O, Entropy change calculated or estimated; Dzidic and Kebarle, 1970 interpolated; M
Δ_rH°	38.5	kcal/mol	ICR	Staley and Beauchamp, 1975	gas phase; switching reaction(Li+)H2O, from graph; Dzidic and Kebarle, 1970 extrapolated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.	cal/mol*K	N/A	Woodin and Beauchamp, 1978	gas phase; switching reaction(Li+)H2O, Entropy change calculated or estimated; Dzidic and Kebarle, 1970 interpolated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	32.1	kcal/mol	ICR	Woodin and Beauchamp, 1978	gas phase; switching reaction(Li+)H2O, Entropy change calculated or estimated; Dzidic and Kebarle, 1970 interpolated; M

( • Ammonia ) + Ammonia = ( • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	33.1	kcal/mol	HPMS	Castleman, Holland, et al., 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	29.7	cal/mol*K	HPMS	Castleman, Holland, et al., 1978	gas phase; M

( • 2 Ammonia ) + Ammonia = ( • 3 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	21.0	kcal/mol	HPMS	Castleman, Holland, et al., 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.3	cal/mol*K	HPMS	Castleman, Holland, et al., 1978	gas phase; M

( • 3 Ammonia ) + Ammonia = ( • 4 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	16.5	kcal/mol	HPMS	Castleman, Holland, et al., 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	32.6	cal/mol*K	HPMS	Castleman, Holland, et al., 1978	gas phase; M

( • 4 Ammonia ) + Ammonia = ( • 5 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	11.1	kcal/mol	HPMS	Castleman, Holland, et al., 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	28.0	cal/mol*K	HPMS	Castleman, Holland, et al., 1978	gas phase; M

( • 5 Ammonia ) + Ammonia = ( • 6 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	9.3	kcal/mol	HPMS	Castleman, Holland, et al., 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.3	cal/mol*K	HPMS	Castleman, Holland, et al., 1978	gas phase; M

+ Ammonia = ( • Ammonia )

By formula: Mg⁺ + H₃N = (Mg⁺ • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	36.8 ± 2.8	kcal/mol	CIDT	Andersen, Muntean, et al., 2000	RCD

( • Ammonia ) + Ammonia = ( • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	29.2 ± 1.6	kcal/mol	CIDT	Andersen, Muntean, et al., 2000	RCD

( • 2 Ammonia ) + Ammonia = ( • 3 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	22.8 ± 2.1	kcal/mol	CIDT	Andersen, Muntean, et al., 2000	RCD

( • 3 Ammonia ) + Ammonia = ( • 4 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	10.4 ± 2.5	kcal/mol	CIDT	Andersen, Muntean, et al., 2000	RCD

( • 4 Ammonia ) + Ammonia = ( • 5 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	13.3 ± 2.8	kcal/mol	CIDT	Andersen, Muntean, et al., 2000	5th ligand is NH3; RCD

+ Ammonia = ( • Ammonia )

By formula: Mn⁺ + H₃N = (Mn⁺ • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	35.1 ± 1.9	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD
Δ_rH°	36.9	kcal/mol	CID	Marinelli and Squires, 1989	gas phase; M

( • Ammonia ) + Ammonia = ( • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	36.3 ± 2.9	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD
Δ_rH°	34.1	kcal/mol	CID	Marinelli and Squires, 1989	gas phase; M

( • 2 Ammonia ) + Ammonia = ( • 3 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	15.3 ± 2.2	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD
Δ_rH°	11.8	kcal/mol	CID	Marinelli and Squires, 1989	gas phase; M

( • 3 Ammonia ) + Ammonia = ( • 4 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.6 ± 1.4	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD

+ Ammonia = H₃N₂O^-

By formula: NO^- + H₃N = H₃N₂O^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	10.40	kcal/mol	N/A	Hendricks, de Clercq, et al., 2002	gas phase; B

+ Ammonia = ( • Ammonia )

By formula: Na⁺ + H₃N = (Na⁺ • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	24.4 ± 1.3	kcal/mol	CIDC	Amicangelo and Armentrout, 2001	Anchor NH3=24.41; RCD
Δ_rH°	24.4 ± 1.3	kcal/mol	CIDT	Armentrout and Rodgers, 2000	RCD
Δ_rH°	25.6 ± 0.2	kcal/mol	HPMS	Hoyau, Norrman, et al., 1999	RCD
Δ_rH°	29.1	kcal/mol	HPMS	Castleman, Holland, et al., 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	21800.	cal/mol*K	HPMS	Hoyau, Norrman, et al., 1999	RCD
Δ_rS°	25.7	cal/mol*K	HPMS	Castleman, Holland, et al., 1978	gas phase; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
18.6	298.	IMRE	McMahon and Ohanessian, 2000	Anchor alanine=39.89; RCD

( • Ammonia ) + Ammonia = ( • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	22. ± 1.	kcal/mol	AVG	N/A	Average of 6 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.1	cal/mol*K	HPMS	Castleman, Holland, et al., 1978	gas phase; M

( • 2 Ammonia ) + Ammonia = ( • 3 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	17.1	kcal/mol	HPMS	Castleman, Holland, et al., 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	24.0	cal/mol*K	HPMS	Castleman, Holland, et al., 1978	gas phase; M

( • 3 Ammonia ) + Ammonia = ( • 4 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	14.7	kcal/mol	HPMS	Castleman, Holland, et al., 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	29.0	cal/mol*K	HPMS	Castleman, Holland, et al., 1978	gas phase; M

( • 4 Ammonia ) + Ammonia = ( • 5 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	10.7	kcal/mol	HPMS	Castleman, Holland, et al., 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	29.8	cal/mol*K	HPMS	Castleman, Holland, et al., 1978	gas phase; M

( • 5 Ammonia ) + Ammonia = ( • 6 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	9.7	kcal/mol	HPMS	Castleman, Holland, et al., 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	29.7	cal/mol*K	HPMS	Castleman, Holland, et al., 1978	gas phase; M

+ Ammonia = ( • Ammonia )

By formula: Ni⁺ + H₃N = (Ni⁺ • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	55.2 ± 3.8	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD
Δ_rH°	51.2	kcal/mol	CID	Marinelli and Squires, 1989	gas phase; M

( • Ammonia ) + Ammonia = ( • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	59.5 ± 3.1	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD
Δ_rH°	55.1	kcal/mol	CID	Marinelli and Squires, 1989	gas phase; M

( • 2 Ammonia ) + Ammonia = ( • 3 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	21.5 ± 1.9	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD
Δ_rH°	17.8	kcal/mol	CID	Marinelli and Squires, 1989	gas phase; M

( • 3 Ammonia ) + Ammonia = ( • 4 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.8 ± 1.4	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD

+ Ammonia = ( • Ammonia )

By formula: Pb⁺ + H₃N = (Pb⁺ • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	28.3	kcal/mol	HPMS	Guo and Castleman, 1991	gas phase; Δ_rS from graph; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.6	cal/mol*K	HPMS	Guo and Castleman, 1991	gas phase; Δ_rS from graph; M

( • Ammonia ) + Ammonia = ( • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	19.2	kcal/mol	HPMS	Guo and Castleman, 1991	gas phase; Δ_rS from graph; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	27.0	cal/mol*K	HPMS	Guo and Castleman, 1991	gas phase; Δ_rS from graph; M

( • 2 Ammonia ) + Ammonia = ( • 3 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	13.0	kcal/mol	HPMS	Guo and Castleman, 1991	gas phase; Δ_rS from graph; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	21.4	cal/mol*K	HPMS	Guo and Castleman, 1991	gas phase; Δ_rS from graph; M

( • 3 Ammonia ) + Ammonia = ( • 4 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	10.7	kcal/mol	HPMS	Guo and Castleman, 1991	gas phase; Δ_rS from graph; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	24.3	cal/mol*K	HPMS	Guo and Castleman, 1991	gas phase; Δ_rS from graph; M

+ Ammonia = ( • Ammonia )

By formula: Rb⁺ + H₃N = (Rb⁺ • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	18.7	kcal/mol	HPMS	Castleman, 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	24.3	cal/mol*K	HPMS	Castleman, 1978	gas phase; M

( • Ammonia ) + Ammonia = ( • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	15.2	kcal/mol	HPMS	Castleman, 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.6	cal/mol*K	HPMS	Castleman, 1978	gas phase; M

( • 2 Ammonia ) + Ammonia = ( • 3 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	13.1	kcal/mol	HPMS	Castleman, 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.1	cal/mol*K	HPMS	Castleman, 1978	gas phase; M

( • 3 Ammonia ) + Ammonia = ( • 4 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	11.4	kcal/mol	HPMS	Castleman, 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	38.0	cal/mol*K	HPMS	Castleman, 1978	gas phase; M

( • 4 Ammonia ) + Ammonia = ( • 5 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	10.2	kcal/mol	HPMS	Castleman, 1978	gas phase; M

+ Ammonia = ( • Ammonia )

By formula: Ti⁺ + H₃N = (Ti⁺ • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	46.6 ± 1.7	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD

( • Ammonia ) + Ammonia = ( • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	41.8 ± 3.6	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD

( • 2 Ammonia ) + Ammonia = ( • 3 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	42.1 ± 3.6	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD

( • 3 Ammonia ) + Ammonia = ( • 4 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	37.3 ± 2.4	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD

+ Ammonia = ( • Ammonia )

By formula: V⁺ + H₃N = (V⁺ • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	45.4 ± 2.6	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD
Δ_rH°	51.9	kcal/mol	CID	Marinelli and Squires, 1989	gas phase; M

( • Ammonia ) + Ammonia = ( • 2 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	39.2 ± 2.2	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD
Δ_rH°	45.0	kcal/mol	CID	Marinelli and Squires, 1989	gas phase; M

( • 2 Ammonia ) + Ammonia = ( • 3 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	24.9 ± 2.6	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD
Δ_rH°	22.6	kcal/mol	CID	Marinelli and Squires, 1989	gas phase; M

( • 3 Ammonia ) + Ammonia = ( • 4 Ammonia )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	22.7 ± 2.6	kcal/mol	CIDT	Walter and Armentrout, 1998	RCD
Δ_rH°	18.7	kcal/mol	CID	Marinelli and Squires, 1989	gas phase; M

IR Spectrum

Go To: Top, Gas phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, Gas Chromatography, 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 Chromatography

Go To: Top, Gas phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, IR Spectrum, References, Notes

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

Kovats' RI, non-polar column, isothermal

View large format table.

Column type	Active phase	Temperature (C)	I	Reference	Comment
Packed	PMS-100	150.	118.	Anderson, Jurel, et al., 1973	He, Celite 545 (44-60 mesh); Column length: 3. m
Packed	PMS-100	180.	131.	Anderson, Jurel, et al., 1973	He, Celite 545 (44-60 mesh); Column length: 3. m

References

Go To: Top, Gas phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, IR Spectrum, Gas Chromatography, Notes

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]

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 D_O(H₂N-H) and D_O(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-_nF_n¹, 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]

Li and Stone, 1990
Li, X.; Stone, A.J., Gas-Phase (CH3)3Si+ Affinities of Alkylamines and Proton Affinities of Trimethylsilyl Alkylamines, Int. J. Mass Spectrom. Ion Proc., 1990, 101, 2-3, 149, https://doi.org/10.1016/0168-1176(90)87008-5 . [all data]

Wojtyniak and Stone, 1986
Wojtyniak, A.C.M.; Stone, A.J., A High-Pressure Mass Spectrometric Study of the Bonding of Trimethylsilylium to Oxygen and Aromatic Bases, Can. J. Chem., 1986, 74, 59. [all data]

Meot-Ner and Field, 1974
Meot-Ner, (Mautner); Field, F.H., Solvation and Association of Protonated Gaseous Amino Acids, J. Am. Chem. Soc., 1974, 96, 10, 3168, https://doi.org/10.1021/ja00817a024 . [all data]

Marinelli and Squires, 1989
Marinelli, P.J.; Squires, R.R., Sequential Solvation of Atomic Transition Metal Ions: The Second Solvent Molecule Can Bind More Strongly than the First, J. Am. Chem. Soc., 1989, 111, 11, 4101, https://doi.org/10.1021/ja00193a052 . [all data]

Spears and Ferguson, 1973
Spears, K.G.; Ferguson, E.E., Termolecular and Saturated Termolecular Kinetics for Li+ and F-, J. Chem. Phys., 1973, 59, 8, 4174, https://doi.org/10.1063/1.1680610 . [all data]

Schwartz, Davico, et al., 2000
Schwartz, R.L.; Davico, G.E.; Kim, J.B.; Lineberger, C.W., Negative Ion Photoelectron Spectroscopy of OH-(NH3), J. Chem. Phys., 2000, 112, 11, 4966, https://doi.org/10.1063/1.481051 . [all data]

Stephan, Futrell, et al., 1982
Stephan, K.; Futrell, J.H.; Peterson, K.I.; Castleman, A.W.; Wagner, H.E.; Djuric, N.; Mark, T.D., An Electron - Impact Study of Ammonia Clusters in a Supersonic Molecular Beam: Appearence Potentials of NH4+, (NH3)2H+, (NH3)3+, (NH3)3H+ and (NH2 NH3)+, Int. J. Mass Spectrom. Ion Phys., 1982, 44, 3-4, 167, https://doi.org/10.1016/0020-7381(82)80023-5 . [all data]

Ng, Trevor, et al., 1977
Ng, C.Y.; Trevor, D.J.; Tiedemann, P.W.; Ceyer, S.T.; Kronebush, B.H.; Mahan, B.H.; Lee, Y.T., Photoinization of Dimeric Polyatomic Molecules: Proton Affinities of H2O and HF, J. Chem. Phys., 1977, 67, 9, 4235, https://doi.org/10.1063/1.435404 . [all data]

Breen, Tzeng, et al., 1989
Breen, J.J.; Tzeng, W.B.; Kilgore, K.; Keesee, R.G.; Castleman, A.W., Intracluster Reactions in Phenylacetylene - Ammonia Clusters Initiated through Resonant Enhanced Ionization, J. Phys. Chem., 1989, 90, 1, 19, https://doi.org/10.1063/1.456521 . [all data]

Andersen, Muntean, et al., 2000
Andersen, A.; Muntean, F.; Walter, D.; Rue, C.; Armentrout, P.B., Collision-Induced Dissociation and Theoretical Studies of Mg+ Complexes with CO, CO2, NH3, CH4, CH3OH, and C6H6, J. Phys. Chem. A, 2000, 104, 4, 692, https://doi.org/10.1021/jp993031t . [all data]

Hendricks, de Clercq, et al., 2002
Hendricks, J.H.; de Clercq, H.L.; Freidhoff, C.B.; Arnold, S.T.; Eaton, J.G.; Fancher, C.; Lyapustina, S.A.; S., Anion solvation at the microscopic level: Photoelectron spectroscopy of the solvated anion clusters, NO-(Y)(n), where Y=Ar, Kr, Xe, N2O, H2S, NH3, H2O, and C2H4(OH)(2), J. Chem. Phys., 2002, 116, 18, 7926-7938, https://doi.org/10.1063/1.1457444 . [all data]

Anderson, Jurel, et al., 1973
Anderson, A.; Jurel, S.; Shymanska, M.; Golender, L., Gas-liquid chromatography of some aliphatic and heterocyclic mono- and pollyfunctional amines. VII. Retention indices of amines in some polar and unpolar stationary phases, Latv. PSR Zinat. Akad. Vestis Kim. Ser., 1973, 1, 51-63. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, IR Spectrum, Gas Chromatography, References

Symbols used in this document:

AE	Appearance energy
IE (evaluated)	Recommended ionization energy
P_c	Critical pressure
P_triple	Triple point pressure
S°_{gas,1 bar}	Entropy of gas at standard conditions (1 bar)
T	Temperature
T_c	Critical temperature
T_fus	Fusion (melting) point
Δ_fH°_gas	Enthalpy of formation of gas at standard conditions
Δ_rG°	Free energy of reaction at standard conditions
Δ_rH°	Enthalpy of reaction at standard conditions
Δ_rS°	Entropy of reaction at standard conditions
Δ_subH	Enthalpy of sublimation
Δ_vapH	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.