Benzene, hexamethyl-

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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

Hexamethyltetracyclo[2.2.0(2,6).0(3,5)]hexane = Benzene, hexamethyl-

By formula: C12H18 = C12H18

Quantity Value Units Method Reference Comment
Δr-345. ± 3.kJ/molCmAdam and Chang, 1969liquid phase; solvent: Pure phase; Heat of isomerization; ALS
Δr-382.kJ/molEqkOth, 1968liquid phase; Heat of isomerization, see Oth, 1969; ALS
Δr-383.kJ/molCmOth, 1968liquid phase; solvent: Toluene-d8; Heat of isomerization at 150°C; ALS

Dewar benzene, hexamethyl- = Benzene, hexamethyl-

By formula: C12H18 = C12H18

Quantity Value Units Method Reference Comment
Δr-235. ± 3.kJ/molCmAdam and Chang, 1969liquid phase; solvent: Pure phase; ALS
Δr-249.kJ/molEqkOth, 1968liquid phase; Heat of isomerization, see Oth, 1969; ALS

C6H7N+ + Benzene, hexamethyl- = (C6H7N+ • Benzene, hexamethyl-)

By formula: C6H7N+ + C12H18 = (C6H7N+ • C12H18)

Bond type: Charge transfer bond (positive ion)

Quantity Value Units Method Reference Comment
Δr71.5kJ/molPHPMSMeot-Ner (Mautner) and El-Shall, 1986gas phase; M
Quantity Value Units Method Reference Comment
Δr102.J/mol*KPHPMSMeot-Ner (Mautner) and El-Shall, 1986gas phase; M

Anti-1,2,3,5,6-pentamethyl-4-methylenebicyclo[3.1.0]hex-2-ene = Benzene, hexamethyl-

By formula: C12H18 = C12H18

Quantity Value Units Method Reference Comment
Δr-179.kJ/molCisoChilds and Mulholland, 1983liquid phase; ALS

References

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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

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