Pyridine
- Formula: C5H5N
- Molecular weight: 79.0999
- IUPAC Standard InChIKey: JUJWROOIHBZHMG-UHFFFAOYSA-N
- CAS Registry Number: 110-86-1
- 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:
- Other names: Azabenzene; Azine; NCI-C55301; Piridina; Pirydyna; Pyridin; Rcra waste number U196; UN 1282; Pyr; CP 32; NSC 406123
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Reaction thermochemistry data
Go To: Top, 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
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
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
C5H4N- + =
By formula: C5H4N- + H+ = C5H5N
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 389.9 ± 2.0 | kcal/mol | IMRE | Schafman and Wenthold, 2007 | gas phase; B |
ΔrH° | 391.0 ± 2.5 | kcal/mol | TDEq | Meot-ner and Kafafi, 1988 | gas phase; anchored to 88MEO scale, not the "87 acidity scale". The Kiefer, Zhang, et al., 1997 BDE is for ortho.; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 382.7 ± 2.0 | kcal/mol | TDEq | Meot-ner and Kafafi, 1988 | gas phase; anchored to 88MEO scale, not the "87 acidity scale". The Kiefer, Zhang, et al., 1997 BDE is for ortho.; B |
ΔrG° | 384.0 ± 3.0 | kcal/mol | IMRB | DePuy, Kass, et al., 1988 | gas phase; Comparable to water in acidity; B |
ΔrG° | <376.3 ± 2.0 | kcal/mol | IMRB | Bruins, Ferrer-Correia, et al., 1978 | gas phase; O- deprotonates; B |
By formula: C5H6N+ + C5H5N = (C5H6N+ • C5H5N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 25.2 | kcal/mol | PHPMS | Meot-Ner (Mautner), 1992 | gas phase; M |
ΔrH° | 24.6 | kcal/mol | PHPMS | Meot-Ner M. and Sieck, 1983 | gas phase; M |
ΔrH° | 26.3 | kcal/mol | HPMS | Holland and Castleman, 1982 | gas phase; M |
ΔrH° | 23.7 | kcal/mol | PHPMS | Meot-Ner (Mautner), 1979 | gas phase; M |
ΔrH° | 23.7 | kcal/mol | PHPMS | Meot-Ner (Mautner), 1979 | gas phase; M |
Quantity | Value | Units | Method | Reference | Comment |
ΔrS° | 29.6 | cal/mol*K | PHPMS | Meot-Ner (Mautner), 1992 | gas phase; M |
ΔrS° | 28.2 | cal/mol*K | PHPMS | Meot-Ner M. and Sieck, 1983 | gas phase; M |
ΔrS° | 32.1 | cal/mol*K | HPMS | Holland and Castleman, 1982 | gas phase; M |
ΔrS° | 28. | cal/mol*K | PHPMS | Meot-Ner (Mautner), 1979 | gas phase; M |
ΔrS° | 28. | cal/mol*K | PHPMS | Meot-Ner (Mautner), 1979 | gas phase; M |
By formula: C5H5N + 3H2 = C5H11N
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -46.31 ± 0.18 | kcal/mol | Eqk | Hales and Herington, 1957 | gas phase; Reanalyzed by Cox and Pilcher, 1970, Original value = -48.32 ± 0.18 kcal/mol; At 400-550 K; ALS |
ΔrH° | -46.12 ± 0.50 | kcal/mol | Eqk | Burrows and King, 1935 | liquid phase; Reanalyzed by Cox and Pilcher, 1970, Original value = -45.00 kcal/mol; At 423-443 K; ALS |
By formula: Cl- + C5H5N = (Cl- • C5H5N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 12.7 ± 2.0 | kcal/mol | TDAs | Hiraoka, Mizuse, et al., 1988 | gas phase; B,M |
Quantity | Value | Units | Method | Reference | Comment |
ΔrS° | 19.7 | cal/mol*K | PHPMS | Hiraoka, Mizuse, et al., 1988 | gas phase; M |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 6.8 ± 2.6 | kcal/mol | TDAs | Hiraoka, Mizuse, et al., 1988 | gas phase; B |
By formula: (C5H6N+ • 2C5H5N) + C5H5N = (C5H6N+ • 3C5H5N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 13.6 | kcal/mol | HPMS | Holland and Castleman, 1982 | gas phase; Entropy change is questionable; M |
Quantity | Value | Units | Method | Reference | Comment |
ΔrS° | 37.9 | cal/mol*K | HPMS | Holland and Castleman, 1982 | gas phase; Entropy change is questionable; M |
By formula: Li+ + C5H5N = (Li+ • C5H5N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 43.2 ± 3.5 | kcal/mol | CIDT | Amunugama and Rodgers, 2000 | RCD |
ΔrH° | 44. | kcal/mol | ICR | Staley and Beauchamp, 1975 | gas phase; switching reaction(Li+)H2O, from graph; Dzidic and Kebarle, 1970 extrapolated; M |
By formula: K+ + C5H5N = (K+ • C5H5N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 21.6 ± 0.9 | kcal/mol | CIDT | Amunugama and Rodgers, 2000 | RCD |
ΔrH° | 20.7 | kcal/mol | HPMS | Davidson and Kebarle, 1976 | gas phase; M |
Quantity | Value | Units | Method | Reference | Comment |
ΔrS° | 18.6 | cal/mol*K | HPMS | Davidson and Kebarle, 1976 | gas phase; M |
By formula: (Ag+ • 2C5H5N) + C5H5N = (Ag+ • 3C5H5N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 16.7 | kcal/mol | HPMS | Holland and Castleman, 1982 | gas phase; M |
Quantity | Value | Units | Method | Reference | Comment |
ΔrS° | 28.0 | cal/mol*K | HPMS | Holland and Castleman, 1982 | gas phase; M |
By formula: (Ag+ • 3C5H5N) + C5H5N = (Ag+ • 4C5H5N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 17.9 | kcal/mol | HPMS | Holland and Castleman, 1982 | gas phase; M |
Quantity | Value | Units | Method | Reference | Comment |
ΔrS° | 40.3 | cal/mol*K | HPMS | Holland and Castleman, 1982 | gas phase; M |
By formula: (Cl- • C5H5N) + C5H5N = (Cl- • 2C5H5N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 11.7 | kcal/mol | PHPMS | Hiraoka, Mizuse, et al., 1988 | gas phase; M |
Quantity | Value | Units | Method | Reference | Comment |
ΔrS° | 22.6 | cal/mol*K | PHPMS | Hiraoka, Mizuse, et al., 1988 | gas phase; M |
By formula: (C5H6N+ • C5H5N) + C5H5N = (C5H6N+ • 2C5H5N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 12.6 | kcal/mol | HPMS | Holland and Castleman, 1982 | gas phase; M |
Quantity | Value | Units | Method | Reference | Comment |
ΔrS° | 29.7 | cal/mol*K | HPMS | Holland and Castleman, 1982 | gas phase; M |
By formula: H2O3- + C5H5N + H2O = C5H7NO3-
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 32.7 ± 2.3 | kcal/mol | N/A | Le Barbu, Schiedt, et al., 2002 | gas phase; Affinity is difference in EAs of lesser solvated species; B |
+ = C5H5NO2-
By formula: O2- + C5H5N = C5H5NO2-
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 21.7 ± 2.3 | kcal/mol | N/A | Le Barbu, Schiedt, et al., 2002 | gas phase; Affinity is difference in EAs of lesser solvated species; B |
+ = C5H5N2O-
By formula: NO- + C5H5N = C5H5N2O-
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 13.6 ± 2.3 | kcal/mol | N/A | Le Barbu, Schiedt, et al., 2002 | gas phase; Affinity is difference in EAs of lesser solvated species; B |
3 + = 3 + KClO3
By formula: 3C5H5NO + ClK = 3C5H5N + KClO3
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 75.2 ± 2.4 | kcal/mol | Cm | Shaofeng and Pilcher, 1988 | solid phase; ALS |
3 + = 3 + KBrO3
By formula: 3C5H5NO + BrK = 3C5H5N + KBrO3
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 75.0 ± 2.3 | kcal/mol | Cm | Shaofeng and Pilcher, 1988 | solid phase; ALS |
By formula: Fe+ + C5H5N = (Fe+ • C5H5N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 53.4 ± 2.2 | kcal/mol | CIDT | Rodgers, Stanley, et al., 2000 | RCD |
By formula: Cr+ + C5H5N = (Cr+ • C5H5N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 47.1 ± 2.8 | kcal/mol | CIDT | Rodgers, Stanley, et al., 2000 | RCD |
By formula: Ti+ + C5H5N = (Ti+ • C5H5N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 51.9 ± 2.3 | kcal/mol | CIDT | Rodgers, Stanley, et al., 2000 | RCD |
By formula: Mn+ + C5H5N = (Mn+ • C5H5N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 43.4 ± 2.1 | kcal/mol | CIDT | Rodgers, Stanley, et al., 2000 | RCD |
By formula: Sc+ + C5H5N = (Sc+ • C5H5N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 55.3 ± 2.5 | kcal/mol | CIDT | Rodgers, Stanley, et al., 2000 | RCD |
By formula: Mg+ + C5H5N = (Mg+ • C5H5N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 47.8 ± 1.6 | kcal/mol | CIDT | Rodgers, Stanley, et al., 2000 | RCD |
By formula: V+ + C5H5N = (V+ • C5H5N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 52.2 ± 3.2 | kcal/mol | CIDT | Rodgers, Stanley, et al., 2000 | RCD |
By formula: Ni+ + C5H5N = (Ni+ • C5H5N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 60.9 ± 3.7 | kcal/mol | CIDT | Rodgers, Stanley, et al., 2000 | RCD |
By formula: Al+ + C5H5N = (Al+ • C5H5N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 45.5 ± 2.5 | kcal/mol | CIDT | Rodgers, Stanley, et al., 2000 | RCD |
By formula: Zn+ + C5H5N = (Zn+ • C5H5N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 59.0 ± 1.7 | kcal/mol | CIDT | Rodgers, Stanley, et al., 2000 | RCD |
By formula: Co+ + C5H5N = (Co+ • C5H5N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 59.0 ± 3.0 | kcal/mol | CIDT | Rodgers, Stanley, et al., 2000 | RCD |
By formula: Cu+ + C5H5N = (Cu+ • C5H5N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 58.7 ± 2.5 | kcal/mol | CIDT | Rodgers, Stanley, et al., 2000 | RCD |
By formula: Na+ + C5H5N = (Na+ • C5H5N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 30.3 ± 0.7 | kcal/mol | CIDT | Amunugama and Rodgers, 2000 | RCD |
References
Go To: Top, Reaction thermochemistry data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Schafman and Wenthold, 2007
Schafman, B.S.; Wenthold, P.G.,
Regioselectivity of pyridine deprotonation in the gas phase,
J. Org. Chem., 2007, 72, 5, 1645-1651, https://doi.org/10.1021/jo062117x
. [all data]
Meot-ner and Kafafi, 1988
Meot-ner, M.; Kafafi, S.A.,
Carbon Acidities of Aromatic Compounds,
J. Am. Chem. Soc., 1988, 110, 19, 6297, https://doi.org/10.1021/ja00227a003
. [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]
DePuy, Kass, et al., 1988
DePuy, C.H.; Kass, S.R.; Bean, G.P.,
Formation and Reactions of Heteroaromatic Anions in the Gas Phase,
J. Org. Chem., 1988, 53, 19, 4427, https://doi.org/10.1021/jo00254a001
. [all data]
Bruins, Ferrer-Correia, et al., 1978
Bruins, A.P.; Ferrer-Correia, A.J.; Harrison, A.G.; Jennings, K.R.; Mithcum, R.K.,
Negative ion chemical ionization mass spectrometry of some aromatic compounds using O-. as the reagent ion,
Adv. Mass Spectrom., 1978, 7, 355. [all data]
Meot-Ner (Mautner), 1992
Meot-Ner (Mautner), M.,
Intermolecular Forces in Organic Clusters,
J. Am. Chem. Soc., 1992, 114, 9, 3312, https://doi.org/10.1021/ja00035a024
. [all data]
Meot-Ner M. and Sieck, 1983
Meot-Ner M.; Sieck, L.W.,
The Ionic Hydrogen Bond. 1. Sterically Hindered Bonds. Solvation and Clustering of Sterically Hindered Amines and Pyridines,
J. Am. Chem. Soc., 1983, 105, 10, 2956, https://doi.org/10.1021/ja00348a005
. [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]
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]
Hales and Herington, 1957
Hales, J.L.; Herington, E.F.G.,
Equilibrium between pyridine and piperidine,
Trans. Faraday Soc., 1957, 53, 616-622. [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]
Burrows and King, 1935
Burrows, G.H.; King, L.A., Jr.,
The free energy change that accompanies hydrogenation of pyridine to piperidine,
J. Am. Chem. Soc., 1935, 57, 1789-1791. [all data]
Hiraoka, Mizuse, et al., 1988
Hiraoka, K.; Mizuse, S.; Yamabe, S.,
Determination of the Stabilities and Structures of X-(C6H6) Clusters (X = Cl, Br, and I),
Chem. Phys. Lett., 1988, 147, 2-3, 174, https://doi.org/10.1016/0009-2614(88)85078-4
. [all data]
Amunugama and Rodgers, 2000
Amunugama, R.; Rodgers, M.T.,
Absolute Alkali Metal Ion Binding Affinities of Several Azines Determined by Threshold Collision-Induced Dissociation and Ab Initio Theory,
Int. J. Mass Spectrom., 2000, 195/196, 439, https://doi.org/10.1016/S1387-3806(99)00145-1
. [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]
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]
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]
Le Barbu, Schiedt, et al., 2002
Le Barbu, K.; Schiedt, J.; Weinkauf, R.; Schlag, E.W.; Nilles, J.M.; Xu, S.J.; Thomas, O.C.; Bowen, K.H.,
Microsolvation of small anions by aromatic molecules: An exploratory study,
J. Chem. Phys., 2002, 116, 22, 9663-9671, https://doi.org/10.1063/1.1475750
. [all data]
Shaofeng and Pilcher, 1988
Shaofeng, L.; Pilcher, G.,
Enthalpy of formation of pyridine-N-oxide: the dissociation enthalpy of the (N-O) bond,
J. Chem. Thermodyn., 1988, 20, 463-465. [all data]
Rodgers, Stanley, et al., 2000
Rodgers, M.T.; Stanley, J.R.; Amunugama, R.,
Periodic Trends in the Binding of Metal Ions to Pyridine Studied by Threshold Collision-Induced Dissociation and Density Functional Theory,
J. Am. Chem. Soc., 2000, 122, 44, 10969, https://doi.org/10.1021/ja0027923
. [all data]
Notes
Go To: Top, Reaction thermochemistry data, References
- Symbols used in this document:
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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