Adenine

Formula: C₅H₅N₅
Molecular weight: 135.1267
IUPAC Standard InChI: InChI=1S/C5H5N5/c6-4-3-5(9-1-7-3)10-2-8-4/h1-2H,(H3,6,7,8,9,10)
IUPAC Standard InChIKey: GFFGJBXGBJISGV-UHFFFAOYSA-N
CAS Registry Number: 73-24-5
Chemical structure:
This structure is also available as a 2d Mol file
Other names: 1H-Purin-6-amine; ADE; Adenin; Adeninimine; Leuco-4; Vitamin B4; 1,6-Dihydro-6-iminopurine; 3,6-Dihydro-6-iminopurine; 6-Amino-1H-purine; 6-Amino-3H-purine; 6-Amino-9H-purine; 6-Aminopurine; 1H-Purine-6-amine; Purine, 6-amino-; USAF CB-18; 1H-Purine, 6-amino-; 6-Amino-7H-purine; 9H-Purine, 1,6-dihydro-6-imino-; 9H-Purin-6-yl-amine; 9H-Purine-6-amine; NSC 14666
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Condensed phase thermochemistry data

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Data compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DH - Eugene S. Domalski and Elizabeth D. Hearing

Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_solid	23.2 ± 0.31	kcal/mol	Ccr	Kirklin and Domalski, 1983	ALS
Δ_fH°_solid	22.95 ± 0.22	kcal/mol	Ccb	Stiehler and Huffman, 1935	Reanalyzed by Cox and Pilcher, 1970, Original value = 21.76 kcal/mol; ALS
Quantity	Value	Units	Method	Reference	Comment
Δ_cH°_solid	-664.20 ± 0.30	kcal/mol	Ccr	Kirklin and Domalski, 1983	ALS
Δ_cH°_solid	-663.99 ± 0.21	kcal/mol	Ccb	Stiehler and Huffman, 1935	Reanalyzed by Cox and Pilcher, 1970, Original value = -663.74 ± 0.21 kcal/mol; ALS
Quantity	Value	Units	Method	Reference	Comment
S°_{solid,1 bar}	36.092	cal/mol*K	N/A	Stiehler and Huffman, 1935, 2	Extrapolation below 90 K, 46.69 J/mol*K.; DH

Constant pressure heat capacity of solid

C_p,solid (cal/mol*K)	Temperature (K)	Reference	Comment
35.13	298.	Kilday, 1978	DH
34.209	298.1	Stiehler and Huffman, 1935, 2	T = 88 to 298 K. Value is unsmoothed experimental datum.; DH

Reaction thermochemistry data

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Data compiled as indicated in comments:
B - John E. Bartmess
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
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.

Individual Reactions

+ = Adenine

By formula: C₅H₄N₅^- + H⁺ = C₅H₅N₅

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	335.1 ± 2.2	kcal/mol	G+TS	Sharma and Lee, 2002	gas phase; Acidity at N-9(imidazole N); B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	328.0 ± 2.0	kcal/mol	IMRB	Sharma and Lee, 2002	gas phase; Acidity at N-9(imidazole N); B
Δ_rG°	344.3 ± 4.0	kcal/mol	IMRB	Sharma and Lee, 2002	gas phase; Less acidic N-10 site(aniline); B

C₅H₆N₅⁺ + Adenine = (C₅H₆N₅⁺ • Adenine )

By formula: C₅H₆N₅⁺ + C₅H₅N₅ = (C₅H₆N₅⁺ • C₅H₅N₅)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	30.3	kcal/mol	PHPMS	Meot-Ner (Mautner), 1979	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	39.	cal/mol*K	PHPMS	Meot-Ner (Mautner), 1979	gas phase; M

+ Adenine = ( • Adenine )

By formula: Na⁺ + C₅H₅N₅ = (Na⁺ • C₅H₅N₅)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	33.4 ± 1.0	kcal/mol	CIDT	Rodgers and Armentrout, 2000	RCD
Δ_rH°	41.1	kcal/mol	CIDC	Cerda and Wesdemiotis, 1996	RCD

+ Adenine = ( • Adenine )

By formula: Ti⁺ + C₅H₅N₅ = (Ti⁺ • C₅H₅N₅)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	≤81.1 ± 3.5	kcal/mol	CIDT	Rodgers and Armentrout, 2002	RCD

+ Adenine = ( • Adenine )

By formula: V⁺ + C₅H₅N₅ = (V⁺ • C₅H₅N₅)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	≤63.4 ± 2.5	kcal/mol	CIDT	Rodgers and Armentrout, 2002	RCD

+ Adenine = ( • Adenine )

By formula: Zn⁺ + C₅H₅N₅ = (Zn⁺ • C₅H₅N₅)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	≥57.0 ± 1.3	kcal/mol	CIDT	Rodgers and Armentrout, 2002	RCD

+ Adenine = ( • Adenine )

By formula: Fe⁺ + C₅H₅N₅ = (Fe⁺ • C₅H₅N₅)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	62.0 ± 2.1	kcal/mol	CIDT	Rodgers and Armentrout, 2002	RCD

+ Adenine = ( • Adenine )

By formula: Cr⁺ + C₅H₅N₅ = (Cr⁺ • C₅H₅N₅)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	55.1 ± 1.8	kcal/mol	CIDT	Rodgers and Armentrout, 2002	RCD

+ Adenine = ( • Adenine )

By formula: Mn⁺ + C₅H₅N₅ = (Mn⁺ • C₅H₅N₅)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	51.6 ± 1.8	kcal/mol	CIDT	Rodgers and Armentrout, 2002	RCD

+ Adenine = ( • Adenine )

By formula: Ni⁺ + C₅H₅N₅ = (Ni⁺ • C₅H₅N₅)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	71.1 ± 2.3	kcal/mol	CIDT	Rodgers and Armentrout, 2002	RCD

+ Adenine = ( • Adenine )

By formula: Co⁺ + C₅H₅N₅ = (Co⁺ • C₅H₅N₅)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	70.0 ± 2.5	kcal/mol	CIDT	Rodgers and Armentrout, 2002	RCD

+ Adenine = ( • Adenine )

By formula: Cu⁺ + C₅H₅N₅ = (Cu⁺ • C₅H₅N₅)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	70.3 ± 2.6	kcal/mol	CIDT	Rodgers and Armentrout, 2002	RCD

+ Adenine = ( • Adenine )

By formula: K⁺ + C₅H₅N₅ = (K⁺ • C₅H₅N₅)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	25.3	kcal/mol	CIDC	Cerda and Wesdemiotis, 1996	RCD

Gas phase ion energetics data

Go To: Top, Condensed phase thermochemistry data, Reaction thermochemistry data, 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
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron

Quantity	Value	Units	Method	Reference	Comment
Proton affinity (review)	225.3	kcal/mol	N/A	Hunter and Lias, 1998	HL
Quantity	Value	Units	Method	Reference	Comment
Gas basicity	218.1	kcal/mol	N/A	Hunter and Lias, 1998	HL

Electron affinity determinations

EA (eV)	Reference	Comment
0.0120 ± 0.0050	Desfrancois, Abdoul-Carime, et al., 1996	Aflatooni, Gallup, et al., 1998: vertical attachment EA = -0.54 eV; B

Ionization energy determinations

IE (eV)	Method	Reference	Comment
8.3 ± 0.1	EI	Verkin, Sukodub, et al., 1976	LLK
8.9 ± 0.1	EI	Lifschitz, Bergmann, et al., 1967	RDSH
8.48	PE	Lin, Yu, et al., 1980	Vertical value; LLK
8.48	PE	Peng, Padva, et al., 1976	Vertical value; LLK
8.44 ± 0.03	PE	Hush and Cheung, 1975	Vertical value; LLK

De-protonation reactions

+ = Adenine

By formula: C₅H₄N₅^- + H⁺ = C₅H₅N₅

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	335.1 ± 2.2	kcal/mol	G+TS	Sharma and Lee, 2002	gas phase; Acidity at N-9(imidazole N); B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	328.0 ± 2.0	kcal/mol	IMRB	Sharma and Lee, 2002	gas phase; Acidity at N-9(imidazole N); B
Δ_rG°	344.3 ± 4.0	kcal/mol	IMRB	Sharma and Lee, 2002	gas phase; Less acidic N-10 site(aniline); B

References

Go To: Top, Condensed phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Notes

Kirklin and Domalski, 1983
Kirklin, D.R.; Domalski, E.S., Enthalpy of combustion of adenine, J. Chem. Thermodyn., 1983, 15, 941-947. [all data]

Stiehler and Huffman, 1935
Stiehler, R.D.; Huffman, H.M., Thermal data. IV. The heats of combustion of adenine, hypoxanthine, guanine, xanthine, uric acid, allantoin and alloxan, J. Am. Chem. Soc., 1935, 57, 1734-1740. [all data]

Cox and Pilcher, 1970
Cox, J.D.; Pilcher, G., Thermochemistry of Organic and Organometallic Compounds, Academic Press, New York, 1970, 1-636. [all data]

Stiehler and Huffman, 1935, 2
Stiehler, R.D.; Huffman, H.M., Thermal data. V. The heat capacities, entropies and free energies of adenine, hypoxanthine, guanine, xanthine, uric acid, allantoin and alloxan, J. Am. Chem. Soc., 1935, 57, 1741-1743. [all data]

Kilday, 1978
Kilday, M.V., Enthalpies of solution of the nucleic acid bases. 1. Adenine in water, J. Res., 1978, NBS 83, 347-369. [all data]

Sharma and Lee, 2002
Sharma, S.; Lee, J.K., Acidity of adenine and adenine derivatives and biological implications. A computational and experimental gas-phase study, J. Org. Chem., 2002, 67, 24, 8360-8365, https://doi.org/10.1021/jo0204303 . [all data]

Meot-Ner (Mautner), 1979
Meot-Ner (Mautner), M., Ion Thermochemistry of Low Volatility Compounds in the Gas Phase. II. Intrinsic Basicities and Hydrogen Bonded Dimers of Nitrogen Heterocyclics and Nucleic Bases, J. Am. Chem. Soc., 1979, 101, 9, 2396, https://doi.org/10.1021/ja00503a027 . [all data]

Rodgers and Armentrout, 2000
Rodgers, M.T.; Armentrout, P.B., Noncovalent Interactions of Nucleic Acid Bases (Uracil, Thymine, and Adenine) with Alkali Metal Ions. Threshold Collision-Induced Dissociation and Theoretical Studies, J. Am. Chem. Soc., 2000, 121, 35, 8548, https://doi.org/10.1021/ja001638d . [all data]

Cerda and Wesdemiotis, 1996
Cerda, B.A.; Wesdemiotis, C., PAs of Peptides, J. Am. Chem. Soc., 1996, 118, 11884. [all data]

Rodgers and Armentrout, 2002
Rodgers, M.T.; Armentrout, P.B., Influence of d orbital occupation on the binding of metal ions to adenine, J. Am. Chem. Soc., 2002, 124, 11, 2678, https://doi.org/10.1021/ja011278+ . [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]

Desfrancois, Abdoul-Carime, et al., 1996
Desfrancois, C.; Abdoul-Carime, H.; Schermann, J.P., Electron Attachment to Isolated Nucleic Acid Bases, J. Chem. Phys., 1996, 104, 19, 7792, https://doi.org/10.1063/1.471484 . [all data]

Aflatooni, Gallup, et al., 1998
Aflatooni, K.; Gallup, G.A.; Burrows, P.D., Electron Attachment Energies of the DNA Bases, J. Phys. Chem., 1998, 102, 31, 6205, https://doi.org/10.1021/jp980865n . [all data]

Verkin, Sukodub, et al., 1976
Verkin, B.I.; Sukodub, L.F.; Yanson, I.K., Ionization potentials of nitrogenous bases of of nucleic acids, Dokl. Akad. Nauk SSSR, 1976, 228, 1452. [all data]

Lifschitz, Bergmann, et al., 1967
Lifschitz, C.; Bergmann, E.D.; Pullman, B., The ionization potentials of biological purines and pyrimidines, Tetrahedron Lett., 1967, 4583. [all data]

Lin, Yu, et al., 1980
Lin, J.; Yu, C.; Peng, S.; Akiyama, I.; Li, K.; Lee, L.K.; LeBreton, P.R., Ultraviolet photoelectron studies of the ground-state electronic structure and gas-phase tautomerism of purine and adenine, J. Am. Chem. Soc., 1980, 102, 4627. [all data]

Peng, Padva, et al., 1976
Peng, S.; Padva, A.; LeBreton, P.R., Ultraviolet photoelectron studies of biological purines: The valence electronic structure of adenine, Proc. Nat. Acad. Sci. U.S.A., 1976, 73, 2966. [all data]

Hush and Cheung, 1975
Hush, N.S.; Cheung, A.S., Ionization potentials and donor properties of nucleic acid bases and related compounds, Chem. Phys. Lett., 1975, 34, 11. [all data]

Notes

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Symbols used in this document:

C_p,solid	Constant pressure heat capacity of solid
EA	Electron affinity
S°_{solid,1 bar}	Entropy of solid at standard conditions (1 bar)
Δ_cH°_solid	Enthalpy of combustion of solid at standard conditions
Δ_fH°_solid	Enthalpy of formation of solid 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

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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