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
- Information on this page:
- Other data available:
- Data at other public NIST sites:
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Phase change data
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 as indicated in comments:
BS - Robert L. Brown and Stephen E. Stein
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos
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 |
---|---|---|---|---|---|
Tboil | 511. ± 4. | K | AVG | N/A | Average of 7 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 325. ± 2. | K | AVG | N/A | Average of 15 out of 17 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Ttriple | 324.780 | K | N/A | Andon and Connett, 1980 | Uncertainty assigned by TRC = 0.002 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔsubH° | 74.8 ± 1.0 | kJ/mol | GS | Widegren and Bruno, 2010 | Based on data from 283. to 313. K.; AC |
ΔsubH° | 79. ± 3. | kJ/mol | V | Lenchitz, Velicky, et al., 1971 | ALS |
ΔsubH° | 79.1 ± 2.5 | kJ/mol | ME | Lenchitz, Velicky, et al., 1971 | AC |
ΔsubH° | 79.1 | kJ/mol | N/A | Lenchitz and Velicky, 1970 | Based on data from 298. to 310. K.; AC |
Enthalpy of vaporization
ΔvapH (kJ/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
52.8 | 422. | EB | Aim, 1994 | Based on data from 407. to 457. K.; AC |
49.8 | 438. | A | Stephenson and Malanowski, 1987 | Based on data from 423. to 512. K.; AC |
54.2 | 402. | N/A | Levin and Shtern, 1938 | Based on data from 387. to 493. K. See also Aim, 1994.; AC |
Antoine Equation Parameters
log10(P) = A − (B / (T + C))
P = vapor pressure (bar)
T = temperature (K)
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Temperature (K) | A | B | C | Reference | Comment |
---|---|---|---|---|---|
420.86 to 506.40 | 4.0924 | 1699.858 | -90.468 | Dreisbach and Shrader, 1949 | Coefficents calculated by NIST from author's data. |
Enthalpy of fusion
ΔfusH (kJ/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
16.81 | 324.8 | Acree, 1991 | AC |
Enthalpy of phase transition
ΔHtrs (kJ/mol) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
16.811 | 324.788 | crystaline, I | liquid | Andon and Connett, 1980, 2 | DH |
70.781 | 318.5 | crystaline, II | liquid | Richardson and Savill, 1979 | Metastable form.; DH |
69.802 | 324.7 | crystaline, I | liquid | Richardson and Savill, 1979 | DH |
Entropy of phase transition
ΔStrs (J/mol*K) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
51.76 | 324.788 | crystaline, I | liquid | Andon and Connett, 1980, 2 | DH |
222.2 | 318.5 | crystaline, II | liquid | Richardson and Savill, 1979 | Metastable; DH |
215.0 | 324.7 | crystaline, I | liquid | Richardson and Savill, 1979 | DH |
Reaction thermochemistry data
Go To: Top, Phase change 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:
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
By formula: Br- + C7H7NO2 = (Br- • C7H7NO2)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 67.8 ± 7.5 | kJ/mol | IMRE | Paul and Kebarle, 1991 | gas phase; ΔGaff measured at 303 K, corrected to 423 K, ΔSaff taken as that of mCF3-nitrobenzene..Br-; B,M |
Quantity | Value | Units | Method | Reference | Comment |
ΔrS° | 92. | J/mol*K | N/A | Paul and Kebarle, 1991 | gas phase; Entropy change calculated or estimated; M |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 28. ± 4.2 | kJ/mol | IMRE | Paul and Kebarle, 1991 | gas phase; ΔGaff measured at 303 K, corrected to 423 K, ΔSaff taken as that of mCF3-nitrobenzene..Br-; B |
Free energy of reaction
ΔrG° (kJ/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
28. | 423. | PHPMS | Paul and Kebarle, 1991 | gas phase; Entropy change calculated or estimated; M |
C7H6NO2- + =
By formula: C7H6NO2- + H+ = C7H7NO2
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 1475. ± 8.8 | kJ/mol | G+TS | Taft and Topsom, 1987 | gas phase; value altered from reference due to change in acidity scale; B |
ΔrH° | 1477. ± 10. | kJ/mol | G+TS | Cumming and Kebarle, 1978 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 1445. ± 8.4 | kJ/mol | IMRE | Taft and Topsom, 1987 | gas phase; value altered from reference due to change in acidity scale; B |
ΔrG° | 1447. ± 8.4 | kJ/mol | IMRE | Cumming and Kebarle, 1978 | gas phase; B |
By formula: Cl- + C7H7NO2 = (Cl- • C7H7NO2)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrG° | 31.4 | kJ/mol | TDEq | French, Ikuta, et al., 1982 | gas phase; B |
Free energy of reaction
ΔrG° (kJ/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
31. | 300. | PHPMS | French, Ikuta, et al., 1982 | gas phase; M |
Gas phase ion energetics data
Go To: Top, Phase change data, Reaction 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) | 815.2 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 782.7 | kJ/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° | 1475. ± 8.8 | kJ/mol | G+TS | Taft and Topsom, 1987 | gas phase; value altered from reference due to change in acidity scale; B |
ΔrH° | 1477. ± 10. | kJ/mol | G+TS | Cumming and Kebarle, 1978 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 1445. ± 8.4 | kJ/mol | IMRE | Taft and Topsom, 1987 | gas phase; value altered from reference due to change in acidity scale; B |
ΔrG° | 1447. ± 8.4 | kJ/mol | IMRE | Cumming and Kebarle, 1978 | gas phase; B |
References
Go To: Top, Phase change data, Reaction 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.
Andon and Connett, 1980
Andon, R.J.L.; Connett, J.E.,
Calibrants for thermal analysis. measurement of their enthalpies of fusion by adiabatic calorimetry.,
Thermochim. Acta, 1980, 42, 241. [all data]
Widegren and Bruno, 2010
Widegren, Jason A.; Bruno, Thomas J.,
Gas Saturation Vapor Pressure Measurements of Mononitrotoluene Isomers from (283.15 to 313.15) K «8224»,
J. Chem. Eng. Data, 2010, 55, 1, 159-164, https://doi.org/10.1021/je900293j
. [all data]
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]
Lenchitz and Velicky, 1970
Lenchitz, Charles; Velicky, Rodolf W.,
Vapor pressure and heat of sublimation of three nitrotoluenes,
J. Chem. Eng. Data, 1970, 15, 3, 401-403, https://doi.org/10.1021/je60046a022
. [all data]
Aim, 1994
Aim, Karel,
Saturated Vapor Pressure Measurements on Isomeric Mononitrotoluenes at Temperatures between 380 and 460 K,
J. Chem. Eng. Data, 1994, 39, 3, 591-594, https://doi.org/10.1021/je00015a044
. [all data]
Stephenson and Malanowski, 1987
Stephenson, Richard M.; Malanowski, Stanislaw,
Handbook of the Thermodynamics of Organic Compounds, 1987, https://doi.org/10.1007/978-94-009-3173-2
. [all data]
Levin and Shtern, 1938
Levin, E.; Shtern, I.,
Educ. Psychol. Meas., 1938, 11, 426. [all data]
Dreisbach and Shrader, 1949
Dreisbach, R.R.; Shrader, S.A.,
Vapor Pressure--Temperature Data on Some Organic Compounds,
Ind. Eng. Chem., 1949, 41, 12, 2879-2880, https://doi.org/10.1021/ie50480a054
. [all data]
Acree, 1991
Acree, William E.,
Thermodynamic properties of organic compounds: enthalpy of fusion and melting point temperature compilation,
Thermochimica Acta, 1991, 189, 1, 37-56, https://doi.org/10.1016/0040-6031(91)87098-H
. [all data]
Andon and Connett, 1980, 2
Andon, R.J.L.; Connett, J.E.,
Calibrants for thermal analysis. Measurement of their enthalpies of fusion by adiabatic calorimetry,
Thermochim. Acta, 1980, 42, 241-247. [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]
Paul and Kebarle, 1991
Paul, G.J.C.; Kebarle, P.,
Stabilities of Complexes of Br- with Substituted Benzenes (SB) Based on Determinations of the Gas-Phase Equilibria Br- + SB = (BrSB)-,
J. Am. Chem. Soc., 1991, 113, 4, 1148, https://doi.org/10.1021/ja00004a014
. [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]
French, Ikuta, et al., 1982
French, M.A.; Ikuta, S.; Kebarle, P.,
Hydrogen bonding of O-H and C-H hydrogen donors to Cl-. Results from mass spectrometric measurement of the ion-molecule equilibria RH + Cl- = RHCl-,
Can. J. Chem., 1982, 60, 1907. [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]
Notes
Go To: Top, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, References
- Symbols used in this document:
AE Appearance energy EA Electron affinity IE (evaluated) Recommended ionization energy T Temperature Tboil Boiling point Tfus Fusion (melting) point Ttriple Triple point temperature ΔHtrs Enthalpy of phase transition ΔStrs Entropy of phase transition ΔfusH Enthalpy of fusion ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions ΔrS° Entropy of reaction at standard conditions ΔsubH° Enthalpy of sublimation at standard conditions ΔvapH Enthalpy of vaporization - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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