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Benzene, 1-methyl-4-nitro-

Gas phase ion energetics data

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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
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 C7H7NO2+ (ion structure unspecified)

Quantity Value Units Method Reference Comment
IE (evaluated)9.46 ± 0.05eVN/AN/AL
Quantity Value Units Method Reference Comment
Proton affinity (review)194.8kcal/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity187.1kcal/molN/AHunter and Lias, 1998HL

Electron affinity determinations

EA (eV) Method Reference Comment
0.95 ± 0.10IMREChowdhury, Heinis, et al., 1986«DELTA»Gea(423 K) = -21.2 kcal/mol; «DELTA»Sea (estimated) = -2.0 eu.; B
0.971 ± 0.048IMREFukuda and McIver, 1985«DELTA»Gea(355 K) = -21.7 kcal/mol; «DELTA»Sea =-2.0, est. from data in Chowdhury, Heinis, et al., 1986; B
0.932 ± 0.087IMREHuh, Kang, et al., 1999«DELTA»G(EA) 343K; anchored to «DELTA»G value. Including anchor «DELTA»S, EA is ca. 0.4 kcal/mol more bound.; B
0.960 ± 0.030ECDChen, Chen, et al., 1992B
<1.100 ± 0.050PDMock and Grimsrud, 1989B

Ionization energy determinations

IE (eV) Method Reference Comment
9.46 ± 0.05PIPECOBaer, Morrow, et al., 1988LL
9.1 ± 0.1PEEgdell, Green, et al., 1975LLK
9.56EIJohnstone and Mellon, 1973LLK
9.76 ± 0.05EIBuchs, 1970RDSH
9.5 ± 0.1EIBrown, 1970RDSH
9.52PEKobayashi and Nagakura, 1974Vertical value; LLK
9.54 ± 0.015PEKobayashi and Nagakura, 1972Vertical value; LLK

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
C5H5+14.9 ± 0.2C2H2+NO2EITajima and Tsuchiya, 1973LLK
C7H7+11.08NO2PIPECOBaer, Morrow, et al., 1988T = 0K; LL
C7H7+11.15NO2PIPECOBaer, Morrow, et al., 1988T = 298K; LL
C7H7+11.3 ± 0.1NO2PIMatyuk, Potapov, et al., 1979LLK
C7H7+12.3 ± 0.3NO2EIMcLafferty and Winkler, 1974LLK
C7H7+11.8 ± 0.1NO2EIBrown, 1970RDSH
C7H7O+10.91 ± 0.05NOPIMatyuk, Potapov, et al., 1979LLK
C7H7O+10.3 ± 0.1NOEIBrown, 1970RDSH

De-protonation reactions

C7H6NO2- + Hydrogen cation = Benzene, 1-methyl-4-nitro-

By formula: C7H6NO2- + H+ = C7H7NO2

Quantity Value Units Method Reference Comment
Deltar352.5 ± 2.1kcal/molG+TSTaft and Topsom, 1987gas phase; value altered from reference due to change in acidity scale; B
Deltar353.1 ± 2.4kcal/molG+TSCumming and Kebarle, 1978gas phase; B
Quantity Value Units Method Reference Comment
Deltar345.3 ± 2.0kcal/molIMRETaft and Topsom, 1987gas phase; value altered from reference due to change in acidity scale; B
Deltar345.9 ± 2.0kcal/molIMRECumming and Kebarle, 1978gas phase; B


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.

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]

Chowdhury, Heinis, et al., 1986
Chowdhury, S.; Heinis, T.; Grimsrud, E.P.; Kebarle, P., Entropy Changes and Electron Affinities from Gas-Phase Electron Transfer Equilibria: A- + B = A + B-, J. Phys. Chem., 1986, 90, 12, 2747, https://doi.org/10.1021/j100403a037 . [all data]

Fukuda and McIver, 1985
Fukuda, E.K.; McIver, R.T., Jr., Relative electron affinities of substituted benzophenones, nitrobenzenes, and quinones. [Anchored to EA(SO2) from 74CEL/BEN], J. Am. Chem. Soc., 1985, 107, 2291. [all data]

Huh, Kang, et al., 1999
Huh, C.; Kang, C.H.; Lee, H.W.; Nakamura, H.; Mishima, M.; Tsuno, Y.; Yamataka, H., Thermodynamic stabilities and resonance demand of aromatic radical anions in the gas phase, Bull. Chem. Soc. Japan, 1999, 72, 5, 1083-1091, https://doi.org/10.1246/bcsj.72.1083 . [all data]

Chen, Chen, et al., 1992
Chen, E.C.M.; Chen, E.S.; Milligan, M.S.; Wentworth, W.E.; Wiley, J.R., Experimental Determination of the Electron Affinities of Nitrobenzene, Nitrotoluenes, Pentafluoronitrobenzene, and Isotopic Nitrobenzenes an, J. Phys. Chem., 1992, 96, 5, 2385, https://doi.org/10.1021/j100184a069 . [all data]

Mock and Grimsrud, 1989
Mock, R.S.; Grimsrud, E.P., Gas-Phase Electron Photodetachment Spectroscopy of the Molecular Anions of Nitroaromatic Hydrocarbons at Atmospheric Pressure, J. Am. Chem. Soc., 1989, 111, 8, 2861, https://doi.org/10.1021/ja00190a020 . [all data]

Baer, Morrow, et al., 1988
Baer, T.; Morrow, J.C.; Shao, J.D.; Olesik, S., Gas-phase heats of formation of C7H7+ isomers: m-Tolyl, p-tolyl, and benzyl ions, J. Am. Chem. Soc., 1988, 110, 5633. [all data]

Egdell, Green, et al., 1975
Egdell, R.; Green, J.C.; Rao, C.N.R., Photoelectron spectra of substituted benzenes, Chem. Phys. Lett., 1975, 33, 600. [all data]

Johnstone and Mellon, 1973
Johnstone, R.A.W.; Mellon, F.A., Effects of induction and resonance in the calculation of ionization potentials of substituted benzenes by perturbation molecular orbital theory, J. Chem. Soc. Faraday Trans. 2, 1973, 69, 36. [all data]

Buchs, 1970
Buchs, A., Etude par spectrometrie de masse de l'ionisation de benzonitriles, de phenylacetonitriles et de N,N-dimethylanilines substitues, Helv. Chim. Acta, 1970, 53, 2026. [all data]

Brown, 1970
Brown, P., Kinetic studies in mass spectrometry. IX. Competing [M-NO2] and [M-NO] reactions in substituted nitrobenzenes. Approximate activation energies from ionization and appearance potentials, Org. Mass Spectrom., 1970, 4, 533. [all data]

Kobayashi and Nagakura, 1974
Kobayashi, T.; Nagakura, S., Photoelectron spectra of substituted benzenes, Bull. Chem. Soc. Jpn., 1974, 47, 2563. [all data]

Kobayashi and Nagakura, 1972
Kobayashi, T.; Nagakura, S., Photoelectron spectra of nitro-compounds, Chem. Lett., 1972, 903. [all data]

Tajima and Tsuchiya, 1973
Tajima, S.; Tsuchiya, T., Energetics consideration of C5H5+ ions produced from various precursors by electron impact, Bull. Chem. Soc. Jpn., 1973, 46, 3291. [all data]

Matyuk, Potapov, et al., 1979
Matyuk, V.M.; Potapov, V.K.; Prokhoda, A.L., Photoexcitation and photoionisation of nitro- derivatives of benzene and toluene, Russ. J. Phys. Chem., 1979, 53, 538. [all data]

McLafferty and Winkler, 1974
McLafferty, F.W.; Winkler, J., Gaseous tropylium, benzyl, tolyl, and norbornadienyl cations, J. Am. Chem. Soc., 1974, 96, 5182. [all data]

Taft and Topsom, 1987
Taft, R.W.; Topsom, R.D., The Nature and Analysis of Substituent Effects, Prog. Phys. Org. Chem., 1987, 16, 1. [all data]

Cumming and Kebarle, 1978
Cumming, J.B.; Kebarle, P., Summary of gas phase measurements involving acids AH. Entropy changes in proton transfer reactions involving negative ions. Bond dissociation energies D(A-H) and electron affinities EA(A), Can. J. Chem., 1978, 56, 1. [all data]


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