Indole
- Formula: C8H7N
- Molecular weight: 117.1479
- IUPAC Standard InChIKey: SIKJAQJRHWYJAI-UHFFFAOYSA-N
- CAS Registry Number: 120-72-9
- 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. - Other names: 1H-Indole; Ketole; 1-Azaindene; 1-Benzazole; 2,3-Benzopyrrole; Benzopyrrole; Indol; 1-H-indol
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Reaction thermochemistry data
Go To: Top, Gas phase ion energetics data, Mass spectrum (electron ionization), References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled as indicated in comments:
B - John E. Bartmess
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
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
C8H6N- + =
By formula: C8H6N- + H+ = C8H7N
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 1472. ± 10. | kJ/mol | TDEq | Meot-ner, Liebman, et al., 1988 | gas phase; anchored to 88MEO scale, not the "87 acidity scale". The Kiefer, Zhang, et al., 1997 BDE is for ortho.; B |
ΔrH° | 1461. ± 8.8 | kJ/mol | G+TS | Taft and Bordwell, 1988 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 1440. ± 8.4 | kJ/mol | TDEq | Meot-ner, Liebman, et al., 1988 | gas phase; anchored to 88MEO scale, not the "87 acidity scale". The Kiefer, Zhang, et al., 1997 BDE is for ortho.; B |
ΔrG° | 1431. ± 8.4 | kJ/mol | IMRE | Taft and Bordwell, 1988 | gas phase; B |
By formula: C2H3O2- + C8H7N = (C2H3O2- • C8H7N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 117. ± 4.2 | kJ/mol | TDAs | Meot-ner, 1988 | gas phase; B,M |
Quantity | Value | Units | Method | Reference | Comment |
ΔrS° | 127. | J/mol*K | PHPMS | Meot-ner, 1988 | gas phase; M |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 78.7 ± 4.2 | kJ/mol | TDAs | Meot-ner, 1988 | gas phase; B |
Gas phase ion energetics data
Go To: Top, Reaction thermochemistry data, Mass spectrum (electron ionization), References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data 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 C8H7N+ (ion structure unspecified)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
IE (evaluated) | 7.7602 ± 0.0006 | eV | N/A | N/A | L |
Quantity | Value | Units | Method | Reference | Comment |
Proton affinity (review) | 933.4 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 901.9 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Electron affinity determinations
EA (eV) | Reference | Comment |
---|---|---|
0.00351 ± 0.00022 | Carles, Desfrancois, et al., 2000 | Dipole bound state; B |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
7.7602 ± 0.0006 | LS | Hager and Wallace, 1988 | LL |
7.7610 ± 0.0006 | PE | Hager, Ivanco, et al., 1985 | LBLHLM |
7.90 | EI | Corval, 1979 | LLK |
8.29 ± 0.05 | EI | Thorstad and Undheim, 1974 | LLK |
7.78 | PE | Dewar, Harget, et al., 1970 | RDSH |
7.75 ± 0.05 | PE | Eland, 1969 | RDSH |
7.91 | PE | Kovac, Klasinc, et al., 1980 | Vertical value; LLK |
7.92 ± 0.05 | PE | Domelsmith, Munchausen, et al., 1977 | Vertical value; LLK |
7.75 ± 0.015 | PE | Gusten, Klasinc, et al., 1976 | Vertical value; LLK |
7.87 | PE | Dolby, Hanson, et al., 1976 | Vertical value; LLK |
De-protonation reactions
C8H6N- + =
By formula: C8H6N- + H+ = C8H7N
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 1472. ± 10. | kJ/mol | TDEq | Meot-ner, Liebman, et al., 1988 | gas phase; anchored to 88MEO scale, not the "87 acidity scale". The Kiefer, Zhang, et al., 1997 BDE is for ortho.; B |
ΔrH° | 1461. ± 8.8 | kJ/mol | G+TS | Taft and Bordwell, 1988 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 1440. ± 8.4 | kJ/mol | TDEq | Meot-ner, Liebman, et al., 1988 | gas phase; anchored to 88MEO scale, not the "87 acidity scale". The Kiefer, Zhang, et al., 1997 BDE is for ortho.; B |
ΔrG° | 1431. ± 8.4 | kJ/mol | IMRE | Taft and Bordwell, 1988 | gas phase; B |
Mass spectrum (electron ionization)
Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director
Spectrum
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Additional Data
View image of digitized spectrum (can be printed in landscape orientation).
Due to licensing restrictions, this spectrum cannot be downloaded.
Owner | NIST Mass Spectrometry Data Center Collection (C) 2014 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved. |
---|---|
Origin | NIST Mass Spectrometry Data Center |
NIST MS number | 353133 |
References
Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Meot-ner, Liebman, et al., 1988
Meot-ner, M.; Liebman, J.F.; Kafafi, S.A.,
Ionic Probes of Aromaticity in Annelated Rings,
J. Am. Chem. Soc., 1988, 110, 18, 5937, https://doi.org/10.1021/ja00226a001
. [all data]
Kiefer, Zhang, et al., 1997
Kiefer, J.H.; Zhang, Q.; Kern, R.D.; Yao, J.; Jursic, B.,
Pyrolysis of Aromatic Azines: Pyrazine, Pyrimidine, and Pyridine,
J. Phys. Chem. A, 1997, 101, 38, 7061, https://doi.org/10.1021/jp970211z
. [all data]
Taft and Bordwell, 1988
Taft, R.W.; Bordwell, F.G.,
Structural and Solvent Effects Evaluated from Acidities Measured in Dimethyl Sulfoxide and in the Gas Phase,
Acc. Chem. Res., 1988, 21, 12, 463, https://doi.org/10.1021/ar00156a005
. [all data]
Meot-ner, 1988
Meot-ner, M.,
Ionic Hydrogen Bond and Ion Solvation. 6. Interaction Energies of the Acetate Ion with Organic Molecules. Comparison of CH3COO- with Cl-, CN-, and SH-,
J. Am. Chem. Soc., 1988, 110, 12, 3854, https://doi.org/10.1021/ja00220a022
. [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]
Carles, Desfrancois, et al., 2000
Carles, S.; Desfrancois, C.; Schermann, J.P.; Smith, D.M.A.; Adamowicz, L.,
Structures and electron affinities of indole-(water)(N) clusters,
J. Chem. Phys., 2000, 112, 8, 3726-3734, https://doi.org/10.1063/1.480938
. [all data]
Hager and Wallace, 1988
Hager, J.W.; Wallace, S.C.,
Two-laser photoionization supersonic jet mass spectrometry of aromatic molecules,
Anal. Chem., 1988, 60, 5. [all data]
Hager, Ivanco, et al., 1985
Hager, J.; Ivanco, M.; Smith, M.A.; Wallace, S.C.,
Solvation effects in jet-cooled Van der Waals Clusters: Two-color threshold photoionization spectroscopy of indole, indole-argon, indole-methane, indole-water and indole-methanol,
Chem. Phys. Lett., 1985, 113, 503. [all data]
Corval, 1979
Corval, M.,
Elimination sous impact electronique de HCN et H a partir de l'Indole. Comparaison avec l'Indolizine,
Org. Mass Spectrom., 1979, 14, 213. [all data]
Thorstad and Undheim, 1974
Thorstad, O.; Undheim, K.,
Mass spectrometry of onium compounds. XXIV. Ionisation potential in structure analysis of pyridodiazo-oxides,
Chem. Scr., 1974, 6, 222. [all data]
Dewar, Harget, et al., 1970
Dewar, M.J.S.; Harget, A.J.; Trinajstic, N.; Worley, S.D.,
Ground states of conjugated molecules-XXI.Benzofurans and benzopyrroles,
Tetrahedron, 1970, 26, 4505. [all data]
Eland, 1969
Eland, J.H.D.,
Photoelectron spectra of conjugated hydrocarbons and heteromolecules,
Intern. J. Mass Spectrom. Ion Phys., 1969, 2, 471. [all data]
Kovac, Klasinc, et al., 1980
Kovac, B.; Klasinc, L.; Stanovnik, B.; Tisler, M.,
Photoelectron spectroscopy of J. Heterocycl. Chem.. Azaindenes azaindolizines (1),
J. Heterocycl. Chem., 1980, 17, 689. [all data]
Domelsmith, Munchausen, et al., 1977
Domelsmith, L.N.; Munchausen, L.L.; Houk, K.N.,
Photoelectron spectra of psychotropic drugs. 1. Phenethylamines, tryptamines, and LSD,
J. Am. Chem. Soc., 1977, 99, 4311. [all data]
Gusten, Klasinc, et al., 1976
Gusten, H.; Klasinc, L.; Ruscic, B.,
Photoelectron spectroscopy of J. Heterocycl. Chem.. Indene analogs,
Z. Naturforsch. A:, 1976, 31, 1051. [all data]
Dolby, Hanson, et al., 1976
Dolby, L.J.; Hanson, G.; Koenig, T.,
The He I photoelectron spectra of N-methylisoindole and N-methylindole,
J. Org. Chem., 1976, 41, 3537. [all data]
Notes
Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), References
- Symbols used in this document:
EA Electron affinity IE (evaluated) Recommended ionization energy ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions ΔrS° Entropy of reaction at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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