Neopentane
- Formula: C5H12
- Molecular weight: 72.1488
- IUPAC Standard InChIKey: CRSOQBOWXPBRES-UHFFFAOYSA-N
- CAS Registry Number: 463-82-1
- 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. - Other names: Propane, 2,2-dimethyl-; tert-Pentane; Tetramethylcarbon; Tetramethylmethane; 1,1,1-Trimethylethane; 2,2-Dimethylpropane; Neo-C5H12; UN 2044; Dimethylpropane
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Gas phase ion energetics 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 evaluated as indicated in comments:
L - 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 |
---|---|---|---|---|---|
IE (evaluated) | ≤10.30 ± 0.08 | eV | N/A | N/A | L |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
10.21 ± 0.04 | PE | Jonas, Schweitzer, et al., 1973 | LLK |
10.3 ± 0.1 | PE | Evans, Green, et al., 1972 | LLK |
10.40 | PE | Dewar and Worley, 1969 | RDSH |
10.35 | PI | Watanabe, Nakayama, et al., 1962 | RDSH |
10.90 | PE | Kimura, Katsumata, et al., 1981 | Vertical value; LLK |
10.9 ± 0.1 | PE | Bieri, Burger, et al., 1977 | Vertical value; LLK |
11.3 | PE | Schmidt and Wilkins, 1972 | Vertical value; LLK |
11.3 | PE | Murrell and Schmidt, 1972 | Vertical value; LLK |
Appearance energy determinations
Ion | AE (eV) | Other Products | Method | Reference | Comment |
---|---|---|---|---|---|
CH3+ | 29.5 ± 0.2 | ? | EI | Olmsted, Street, et al., 1964 | RDSH |
CH3+ | 13.14 | ? | EI | Lampe and Field, 1959 | RDSH |
C2H3+ | 17.95 | ? | EI | Lampe and Field, 1959 | RDSH |
C2H5+ | 13.81 | ? | EI | Lampe and Field, 1959 | RDSH |
C3H3+ | 17.08 | ? | EI | Lampe and Field, 1959 | RDSH |
C3H5+ | 13.13 | ? | EI | Lampe and Field, 1959 | RDSH |
C4H8+ | 10.39 ± 0.02 | CH4 | PI | Steiner, Giese, et al., 1961 | RDSH |
C4H9+ | 10.35 | CH3 | PI | Chesnavich, Su, et al., 1978 | LLK |
C4H9+ | 10.56 | CH3 | EI | Lossing and Semeluk, 1970 | RDSH |
C4H9+ | 10.57 ± 0.02 | CH3 | PI | Steiner, Giese, et al., 1961 | RDSH |
De-protonation reactions
C5H11- + =
By formula: C5H11- + H+ = C5H12
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 408.9 ± 2.0 | kcal/mol | Bran | DePuy, Gronert, et al., 1989 | gas phase; B |
ΔrH° | 411. ± 10. | kcal/mol | CIDT | Graul and Squires, 1990 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 400.1 ± 2.1 | kcal/mol | H-TS | DePuy, Gronert, et al., 1989 | gas phase; B |
References
Go To: Top, Gas phase ion energetics data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Jonas, Schweitzer, et al., 1973
Jonas, A.E.; Schweitzer, G.K.; Grimm, F.A.; Carlson, T.A.,
The photoelectron spectra of the tetrafluoro and tetramethyl compounds of the group IV elements,
J. Electron Spectrosc. Relat. Phenom., 1973, 1, 29. [all data]
Evans, Green, et al., 1972
Evans, S.; Green, J.C.; Joachim, P.J.; Orchard, A.F.; Turner, D.W.; Maier, J.P.,
Electronic structures of the Group IVB tetramethyls by helium-(I) photoelectron spectroscopy,
J. Chem. Soc. Faraday Trans. 2, 1972, 68, 905. [all data]
Dewar and Worley, 1969
Dewar, M.J.S.; Worley, S.D.,
Photoelectron spectra of molecules. I. Ionization potentials of some organic molecules and their interpretation,
J. Chem. Phys., 1969, 50, 654. [all data]
Watanabe, Nakayama, et al., 1962
Watanabe, K.; Nakayama, T.; Mottl, J.,
Ionization potentials of some molecules,
J. Quant. Spectry. Radiative Transfer, 1962, 2, 369. [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]
Bieri, Burger, et al., 1977
Bieri, G.; Burger, F.; Heilbronner, E.; Maier, J.P.,
Valence ionization enrgies of hydrocarbons,
Helv. Chim. Acta, 1977, 60, 2213. [all data]
Schmidt and Wilkins, 1972
Schmidt, W.; Wilkins, B.T.,
Das "Equivalent Orbital" (EO)-verfahren zur interpretation von photoelektronen(PE)-spektren: Neopentan,
Angew. Chem., 1972, 84, 168. [all data]
Murrell and Schmidt, 1972
Murrell, J.N.; Schmidt, W.,
Photoelectron spectroscopic correlation of the molecular orbitals of methane, ethane, propane, isobutane and neopentane,
J. Chem. Soc. Faraday Trans. 2, 1972, 68, 1709. [all data]
Olmsted, Street, et al., 1964
Olmsted, J., III; Street, K., Jr.; Newton, A.S.,
Excess-kinetic-energy ions in organic mass spectra,
J. Chem. Phys., 1964, 40, 2114. [all data]
Lampe and Field, 1959
Lampe, F.W.; Field, F.H.,
The decomposition of neopentane under electron impact,
J. Am. Chem. Soc., 1959, 81, 3238. [all data]
Steiner, Giese, et al., 1961
Steiner, B.; Giese, C.F.; Inghram, M.G.,
Photoionization of alkanes. Dissociation of excited molecular ions,
J. Chem. Phys., 1961, 34, 189. [all data]
Chesnavich, Su, et al., 1978
Chesnavich, W.J.; Su, T.; Bowers, M.T.,
Reactions of vibrationally excited ions. A theoretical and experimental analysis of the reaction (C4H9+) + NH3 Ü NH4+ + C4H8,
J. Am. Chem. Soc., 1978, 100, 4362. [all data]
Lossing and Semeluk, 1970
Lossing, F.P.; Semeluk, G.P.,
Free radicals by mass spectrometry. XLII.Ionization potentials and ionic heats of formation for C1-C4 alkyl radicals,
Can. J. Chem., 1970, 48, 955. [all data]
DePuy, Gronert, et al., 1989
DePuy, C.H.; Gronert, S.; Barlow, S.E.; Bierbaum, V.M.; Damrauer, R.,
The Gas Phase Acidities of the Alkanes,
J. Am. Chem. Soc., 1989, 111, 6, 1968, https://doi.org/10.1021/ja00188a003
. [all data]
Graul and Squires, 1990
Graul, S.T.; Squires, R.R.,
Gas-Phase Acidities Derived from Threshold Energies for Activated Reactions,
J. Am. Chem. Soc., 1990, 112, 7, 2517, https://doi.org/10.1021/ja00163a007
. [all data]
Notes
Go To: Top, Gas phase ion energetics data, References
- Symbols used in this document:
AE Appearance energy IE (evaluated) Recommended ionization energy ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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