Amino radical

Formula: H₂N
Molecular weight: 16.0226
IUPAC Standard InChI: InChI=1S/H2N/h1H2
IUPAC Standard InChIKey: MDFFNEOEWAXZRQ-UHFFFAOYSA-N
CAS Registry Number: 13770-40-6
Chemical structure:
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Gas phase ion energetics data

Go To: Top, References, Notes

Data evaluated as indicated in comments:
HL - Edward P. Hunter and 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 H₂N⁺ (ion structure unspecified)

Quantity	Value	Units	Method	Reference	Comment
Proton affinity (review)	184.8	kcal/mol	N/A	Hunter and Lias, 1998	HL
Quantity	Value	Units	Method	Reference	Comment
Gas basicity	177.3	kcal/mol	N/A	Hunter and Lias, 1998	HL
Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_{(+) ion}	302.0 ± 1.5	kcal/mol	N/A	N/A
Quantity	Value	Units	Method	Reference	Comment
Δ_fH_{(+) ion,0K}	302.7 ± 1.5	kcal/mol	N/A	N/A

Electron affinity determinations

EA (eV)	Method	Reference	Comment
0.7710 ± 0.0050	LPES	Wickham-Jones, Ervin, et al., 1989	B
0.766 ± 0.036	D-EA	MacKay, Hemsworth, et al., 1976	B
0.776 ± 0.037	LPES	Celotta, Bennett, et al., 1974	B
0.744 ± 0.022	LPD	Smyth and Brauman, 1972	B
0.760 ± 0.040	PD	Feldman, 1971	B
0.740 ± 0.030	LPD	Smyth, McIver, et al., 1971	B
0.722924	N/A	Check, Faust, et al., 2001	HCrO3(t); ; ΔS(EA)=6.6; B
1.11879	SI	Page and Goode, 1969	The Magnetron method, lacking mass analysis, is not considered reliable.; B

Ionization energy determinations

IE (eV)	Method	Reference	Comment
10.78 ± 0.05	DER	Qi, Sheng, et al., 1995	LL
11.14 ± 0.01	PI	Gibson, Greene, et al., 1985	LBLHLM
11.46 ± 0.01	PE	Dunlavey, Dyke, et al., 1980	LLK
11.7	EI	Melton, 1966	RDSH
11.22	DER	Dibeler, Walker, et al., 1966	RDSH
11.4 ± 0.1	EI	Foner and Hudson, 1958	RDSH
12.0	EI	Locht, Servais, et al., 1988	Vertical value; LL
12.00 ± 0.01	PE	Dunlavey, Dyke, et al., 1980	Vertical value; LLK

Appearance energy determinations

Ion	AE (eV)	Other Products	Method	Reference	Comment
HN⁺	17.440 ± 0.005	H	PI	Gibson, Greene, et al., 1985	LBLHLM

De-protonation reactions

HN^- + = Amino radical

By formula: HN^- + H⁺ = H₂N

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	397.87 ± 0.48	kcal/mol	D-EA	Neumark, Lykke, et al., 1985	gas phase; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	390.99 ± 0.57	kcal/mol	H-TS	Neumark, Lykke, et al., 1985	gas phase; B

References

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

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]

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]

Celotta, Bennett, et al., 1974
Celotta, R.S.; Bennett, R.A.; Hall, J.L., Laser Photodetachment Determination of the Electron Affinities of OH, NH₂, NH, SO₂, and S₂, J. Chem. Phys., 1974, 60, 5, 1740, https://doi.org/10.1063/1.1681268 . [all data]

Smyth and Brauman, 1972
Smyth, K.C.; Brauman, J.I., Photodetachment of electrons from amide and arsenide ions: The electron affinities of NH₂ and AsH₂., J. Chem. Phys., 1972, 56, 4620. [all data]

Feldman, 1971
Feldman, D., Photoablosung von Elektronen bei Si^- und NH₂^-, Z. Naturforsch. A, 1971, 26, 1100. [all data]

Smyth, McIver, et al., 1971
Smyth, K.C.; McIver, R.T.; Brauman, J.I.; Wallace, R.W., Photodetachment of negative ions using a continuously tunable laser and an ICR spectrometer, J. Chem. Phys., 1971, 54, 2758. [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]

Page and Goode, 1969
Page, F.M.; Goode, G.C., Negative Ions and the Magnetron., Wiley, NY, 1969. [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]

Gibson, Greene, et al., 1985
Gibson, S.; Greene, J.; Berkowitz, J., Photoionization of the amidogen radical, J. Chem. Phys., 1985, 83, 4319. [all data]

Dunlavey, Dyke, et al., 1980
Dunlavey, S.J.; Dyke, J.M.; Jonathan, N.; Morris, A., Vacuum ultraviolet photoelectron spectroscopy of transient species. Part 11. The NH₂(X(2)B1) radical, Mol. Phys., 1980, 39, 1121. [all data]

Melton, 1966
Melton, C.E., Study by mass spectrometry of the decomposition of ammonia by ionizing radiation in a wide-range radiolysis source, J. Chem. Phys., 1966, 45, 4414. [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]

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]

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]

Neumark, Lykke, et al., 1985
Neumark, D.M.; Lykke, K.R.; Anderson, T.; Lineberger, W.C., Infrared Spectrum and Autodetachment Dynamics of NH-, J. Chem. Phys., 1985, 83, 9, 4364, https://doi.org/10.1063/1.449052 . [all data]

Notes

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

Symbols used in this document:

AE	Appearance energy
EA	Electron affinity
Δ_fH_{(+) ion,0K}	Enthalpy of formation of positive ion at 0K
Δ_rG°	Free energy of reaction at standard conditions
Δ_rH°	Enthalpy of reaction at standard conditions

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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