Benzene, hexamethyl-
- Formula: C12H18
- Molecular weight: 162.2713
- IUPAC Standard InChIKey: YUWFEBAXEOLKSG-UHFFFAOYSA-N
- CAS Registry Number: 87-85-4
- 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: Hexamethylbenzene; Mellitene; 1,2,3,4,5,6-Hexamethylbenzene
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Reaction thermochemistry 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 compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
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Individual Reactions
By formula: C12H18 = C12H18
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -82.5 ± 0.8 | kcal/mol | Cm | Adam and Chang, 1969 | liquid phase; solvent: Pure phase; Heat of isomerization; ALS |
ΔrH° | -91.2 | kcal/mol | Eqk | Oth, 1968 | liquid phase; Heat of isomerization, see Oth, 1969; ALS |
ΔrH° | -91.5 | kcal/mol | Cm | Oth, 1968 | liquid phase; solvent: Toluene-d8; Heat of isomerization at 150°C; ALS |
By formula: C12H18 = C12H18
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -56.2 ± 0.6 | kcal/mol | Cm | Adam and Chang, 1969 | liquid phase; solvent: Pure phase; ALS |
ΔrH° | -59.5 | kcal/mol | Eqk | Oth, 1968 | liquid phase; Heat of isomerization, see Oth, 1969; ALS |
By formula: C6H7N+ + C12H18 = (C6H7N+ • C12H18)
Bond type: Charge transfer bond (positive ion)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 17.1 | kcal/mol | PHPMS | Meot-Ner (Mautner) and El-Shall, 1986 | gas phase; M |
Quantity | Value | Units | Method | Reference | Comment |
ΔrS° | 24.3 | cal/mol*K | PHPMS | Meot-Ner (Mautner) and El-Shall, 1986 | gas phase; M |
By formula: C12H18 = C12H18
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -42.7 | kcal/mol | Ciso | Childs and Mulholland, 1983 | liquid phase; ALS |
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.
Adam and Chang, 1969
Adam, W.; Chang, J.C.,
Kinetics and thermochemistry of valence isomerization by differential scanning calorimetry: the case of hexamethylprismane and hexamethyldewarbenzene,
Int. J. Chem. Kinet., 1969, 1, 487-492. [all data]
Oth, 1968
Oth, J.F.M.,
The kinetics and thermochemistry of the thermal rearrangement of hexamethylbicyclo[2.2.0]hexa-2,5-diene (hexamethyldewarbenzene) and of hexamethyltetracyclo[2.2.0,0(2,6).0(3,5)]hexane (hexamethylprismane),
Chem. Ber., 1968, 47, 1185-1195. [all data]
Oth, 1969
Oth, J.F.M.,
The kinetics and thermochemistry of the thermal rearrangement of hexamethyl(Dewar benzene) and of hexamethylprismane,
Angew. Chem. Int. Ed. Engl., 1969, 7, 646. [all data]
Meot-Ner (Mautner) and El-Shall, 1986
Meot-Ner (Mautner), M.; El-Shall, M.S.,
Ionic Charge Transfer Complexes. 1. Cationic Complexes with Delocalized and Partially Localized pi Systems,
J. Am. Chem. Soc., 1986, 108, 15, 4386, https://doi.org/10.1021/ja00275a026
. [all data]
Childs and Mulholland, 1983
Childs, R.F.; Mulholland, D.L.,
Thermochemical relationships between some bicyclohexenyl and benzenium cations,
J. Am. Chem. Soc., 1983, 105, 96-99. [all data]
Notes
Go To: Top, Reaction thermochemistry data, References
- Symbols used in this document:
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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