Benzene, 1-methyl-4-nitro-
- Formula: C7H7NO2
- Molecular weight: 137.1360
- IUPAC Standard InChIKey: ZPTVNYMJQHSSEA-UHFFFAOYSA-N
- CAS Registry Number: 99-99-0
- 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. - Species with the same structure:
- Other names: Toluene, p-nitro-; p-Methylnitrobenzene; p-Nitrotoluene; PNT; 1-Methyl-4-nitrobenzene; 4-Methylnitrobenzene; 4-Nitrotoluene; 4-Nitrotoluol; NCI-C60537; NSC 9579
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- Other data available:
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Gas phase thermochemistry data
Go To: Top, Condensed phase 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: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°gas | 7.38 ± 0.94 | kcal/mol | Ccb | Lenchitz, Velicky, et al., 1971 |
Condensed phase thermochemistry data
Go To: Top, Gas phase 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 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 |
---|---|---|---|---|---|
ΔfH°solid | -11.52 ± 0.72 | kcal/mol | Ccb | Lenchitz, Velicky, et al., 1971 | ALS |
Quantity | Value | Units | Method | Reference | Comment |
ΔcH°solid | -885.96 ± 0.70 | kcal/mol | Ccb | Lenchitz, Velicky, et al., 1971 | ALS |
ΔcH°solid | -888.8 | kcal/mol | Ccb | Garner and Abernethy, 1921 | ALS |
Constant pressure heat capacity of solid
Cp,solid (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
41.18 | 298.15 | Richardson and Savill, 1979 | crystaline, I phase; T = 270 to 340 K. Equations only. Data for stable and metastable crystal form.; DH |
Gas phase ion energetics data
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, 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
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 ± 0.05 | eV | N/A | N/A | L |
Quantity | Value | Units | Method | Reference | Comment |
Proton affinity (review) | 194.8 | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 187.1 | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
Electron affinity determinations
EA (eV) | Method | Reference | Comment |
---|---|---|---|
0.95 ± 0.10 | IMRE | Chowdhury, Heinis, et al., 1986 | ΔGea(423 K) = -21.2 kcal/mol; ΔSea (estimated) = -2.0 eu.; B |
0.971 ± 0.048 | IMRE | Fukuda and McIver, 1985 | ΔGea(355 K) = -21.7 kcal/mol; ΔSea =-2.0, est. from data in Chowdhury, Heinis, et al., 1986; B |
0.932 ± 0.087 | IMRE | Huh, Kang, et al., 1999 | ΔG(EA) 343K; anchored to ΔG value. Including anchor ΔS, EA is ca. 0.4 kcal/mol more bound.; B |
0.960 ± 0.030 | ECD | Chen, Chen, et al., 1992 | B |
<1.100 ± 0.050 | PD | Mock and Grimsrud, 1989 | B |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
9.46 ± 0.05 | PIPECO | Baer, Morrow, et al., 1988 | LL |
9.1 ± 0.1 | PE | Egdell, Green, et al., 1975 | LLK |
9.56 | EI | Johnstone and Mellon, 1973 | LLK |
9.76 ± 0.05 | EI | Buchs, 1970 | RDSH |
9.5 ± 0.1 | EI | Brown, 1970 | RDSH |
9.52 | PE | Kobayashi and Nagakura, 1974 | Vertical value; LLK |
9.54 ± 0.015 | PE | Kobayashi and Nagakura, 1972 | Vertical value; LLK |
Appearance energy determinations
Ion | AE (eV) | Other Products | Method | Reference | Comment |
---|---|---|---|---|---|
C5H5+ | 14.9 ± 0.2 | C2H2+NO2 | EI | Tajima and Tsuchiya, 1973 | LLK |
C7H7+ | 11.08 | NO2 | PIPECO | Baer, Morrow, et al., 1988 | T = 0K; LL |
C7H7+ | 11.15 | NO2 | PIPECO | Baer, Morrow, et al., 1988 | T = 298K; LL |
C7H7+ | 11.3 ± 0.1 | NO2 | PI | Matyuk, Potapov, et al., 1979 | LLK |
C7H7+ | 12.3 ± 0.3 | NO2 | EI | McLafferty and Winkler, 1974 | LLK |
C7H7+ | 11.8 ± 0.1 | NO2 | EI | Brown, 1970 | RDSH |
C7H7O+ | 10.91 ± 0.05 | NO | PI | Matyuk, Potapov, et al., 1979 | LLK |
C7H7O+ | 10.3 ± 0.1 | NO | EI | Brown, 1970 | RDSH |
De-protonation reactions
C7H6NO2- + =
By formula: C7H6NO2- + H+ = C7H7NO2
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 352.5 ± 2.1 | kcal/mol | G+TS | Taft and Topsom, 1987 | gas phase; value altered from reference due to change in acidity scale; B |
ΔrH° | 353.1 ± 2.4 | kcal/mol | G+TS | Cumming and Kebarle, 1978 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 345.3 ± 2.0 | kcal/mol | IMRE | Taft and Topsom, 1987 | gas phase; value altered from reference due to change in acidity scale; B |
ΔrG° | 345.9 ± 2.0 | kcal/mol | IMRE | Cumming and Kebarle, 1978 | gas phase; B |
References
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, 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.
Lenchitz, Velicky, et al., 1971
Lenchitz, C.; Velicky, R.W.; Silvestro, G.; Schlosberg, L.P.,
Thermodynamic properties of several nitrotoluenes,
J. Chem. Thermodyn., 1971, 3, 689-692. [all data]
Garner and Abernethy, 1921
Garner, W.E.; Abernethy, C.L.,
Heats of combustion and formation of nitro-compounds. Part I. - Benzene, toluene, phenol and methylaniline series,
Proc. Roy. Soc. London A, 1921, 213-235. [all data]
Richardson and Savill, 1979
Richardson, M.J.; Savill, N.G.,
Free energy changes by differential scanning calorimetry: application to a low energy but metastable form of p-nitrotoluene,
Thermochim. Acta, 1979, 30, 327-337. [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]
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]
Notes
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Gas phase ion energetics data, References
- Symbols used in this document:
AE Appearance energy Cp,solid Constant pressure heat capacity of solid EA Electron affinity IE (evaluated) Recommended ionization energy ΔcH°solid Enthalpy of combustion of solid at standard conditions ΔfH°gas Enthalpy of formation of gas at standard conditions ΔfH°solid Enthalpy of formation of solid at standard conditions 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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