The energetics of aromatic hydrocarbons: An experimental thermochemical perspective

Chemical Reviews

Volumn 101, Issue 5, 2001, Pages 1541-1566

  Slayden, Suzanne W ^a   Liebman, Joel F ^b  

^a GEORGE MASON UNIVERSITY   (United States)

^b UNIVERSITY OF MARYLAND   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

HETEROCYCLIC COMPOUNDS;

CHARACTERIZATION; COMBUSTION; ELECTRON DIFFRACTION; ENTHALPY; FULLERENES; HYDROGENATION; NEGATIVE IONS; PHASE TRANSITIONS; SPECTRUM ANALYSIS; SUBLIMATION; SYNTHESIS (CHEMICAL); THERMOMECHANICAL TREATMENT; VAPORIZATION;

BENZENE;

EID: 0035353485     PISSN: 00092665     EISSN: None     Source Type: Journal    
DOI: 10.1021/cr990324+     Document Type: Article

References (165)

1. Pedley, J.B.; Naylor, R.D.; Kirby, S.P. Thermochemical Data of Organic Compounds, 2nd ed.; Chapman & Hall: New York, 1986. The 3rd edition of this compendium (Pedley, J.B. Thermochemical Data and Structures of Organic Compounds, 3rd ed.; Thermodynamics Research Center: College Station, TX, 1994) is not yet as widely cited, even recently, as the earlier edition we prefer. In most cases, the primary literature citations in the two editions are identical. For some compounds, the recommended values have been reevaluated with relatively little change. Readers who wish to search for unevaluated data which has appeared since 1994 can consult Afeefy, H.Y.; Liebman, J.F.; Stein, S.E. Neutral Thermochemical Data. In NIST Chemistry WebBook, NIST Standard Reference Database 69; Mallard, W.G., Linstrom, W.G. Eds.; National Institute of Standards and Technology: Gaithersburg, MD, February 2000, http://webbook.nist.gov.
2. Chickos, J.S.; Hyman, A.S.; Laden, L.H.; Liebman, J.F. J. Org. Chem. 1981, 46, 4294.
3. Stein, S.E.; Golden, D.M.; Benson, S.W. J. Phys. Chem. 1977, 81, 314.
4. This is seemingly the case for even well-known heterocycles. For example, consider pyridine and the isomeric diazines: there is a 10 kJ/mol discrepancy between experiment and well-defined theory for pyrimidine and pyrazine (Wiberg, K.B.; Nakaji, D.; Breneman, C.M. J. Am. Chem. Soc. 1989, 111, 4178).
5. Slayden, S.W.; Liebman, J.F. In Supplement A3: The chemistry of the double-bonded functional groups; Patai, S., Ed.; Wiley: Chichester, 1997. A variety of noncalorimetric measurement techniques were brought to bear on the energetics of methylenimine resulting in incompatible, and still inexplicable, enthalpy of formation differences.
6. 2NH (using W2 theory) is 88.3 ± 2.1 kJ/mol, see: de Oliveira, G.; Martin, J.M.L., Silwal, I.K.C.; Liebman, J.F. J. Comput. Chem., in press.
7. Liebman, J.F.; Perks, H.M. In The Chemistry of Enamines; Rappoport, Z., Ed.; Wiley: Chichester, 1994; p 155.
8. Katritzky, A.R.; Karelson, M.; Sild, S.; Krygowski, T.M.; Jug, K. J. Org. Chem. 1998, 63, 5228.
9. Hopf, H. Classics in Hydrocarbon Chemistry: Syntheses, Concepts, Perspectives; Wiley-VCH: Weinheim, 2000.
10. Minkin, V.I.; Glukhovtsev, M.N.; Simkin, B.I. Aromaticity and Antiaromaticity: Electronic and Structural Aspects; Wiley: New York; 1994.
11. Garratt, P.J. Aromaticity, 2nd ed.; Wiley: New York, 1986.
12. Sainbury, M. Aromatic Character; Oxford University Press: Oxford, 1994.
13. Breslow, R.; Brown, J.; Gajewski, J.J. J. Am. Chem. Soc. 1967, 89, 4383.
14. Kistiakowsky, G.B.; Ruhoff, J.R.; Smith, H.A.; Vaughan, W.E. J. Am. Chem. Soc. 1936, 58, 137. Kistiakowsky, G.B.; Ruhoff, J.R.; Smith, H.A.; Vaughan, W.E. J. Am. Chem. Soc. 1936, 58, 146.
15. Kistiakowsky, G.B.; Ruhoff, J.R.; Smith, H.A.; Vaughan, W.E. J. Am. Chem. Soc. 1936, 58, 137. Kistiakowsky, G.B.; Ruhoff, J.R.; Smith, H.A.; Vaughan, W.E. J. Am. Chem. Soc. 1936, 58, 146.
16. The originally measured value, -119.6 ± 0.4 kJ/mol, was reanalyzed by Cox, J.D.; Pilcher, G. Thermochemistry of Organic and Organometallic Compounds; Academic Press: New York, 1970.
17. The name "benzene" arose before the names cyclohexene, cyclohexadiene, and cyclohexatriene. Indeed, as late as the first third of the 20th century, cyclohexene and the cyclohexadienes were often referred to as tetra-and dihydrobenzenes. We know of no attempt, whether by Chemical Abstracts or IUPAC or any other nomenclature-conscious organization, to replace "benzene" by "cyclohexatriene". It is almost a general rule that the more stable species have retained their trivial names because they have been known longer by the chemical community, cf. furan vs oxirene and oxepin.
18. The original measured enthalpy of hydrogenation, -208.4 ± 0.63 kJ/mol, was reanalyzed by Cox, J.D.; Pilcher, G. Thermochemistry of Organic and Organometallic Compounds; Academic Press: New York, 1970. The gaseous enthalpy of formation of benzene from ref 1 is 82.6 ± 0.7 kJ/mol.
19. Dewar, M.J.S. Molecular Orbital Theory of Organic Chemistry; McGraw-Hill New York, 1969.
20. Streitwieser, A. Molecular Orbital Theory for Organic Chemists; Wiley: New York, 1961 and references therein.
21. See ref 10 and references therein. The first applications of the homodesmotic reaction schemes are found in George, P.; Trachtman, M.; Bock, C.W.; Brett, A.M. J. Chem. Soc., Perkin Trans. 2 1976, 1222 and George, P.; Trachtman, M.; Brett, A.M.; Bock, C.W. J. Chem. Soc., Perkin Trans. 2 1977, 1036.
22. See ref 10 and references therein. The first applications of the homodesmotic reaction schemes are found in George, P.; Trachtman, M.; Bock, C.W.; Brett, A.M. J. Chem. Soc., Perkin Trans. 2 1976, 1222 and George, P.; Trachtman, M.; Brett, A.M.; Bock, C.W. J. Chem. Soc., Perkin Trans. 2 1977, 1036.
23. Glukhovtsev, M.N.; Bach, R.D.; Laiter, S. J. Mol. Struct. (Theochem) 1997, 417, 123.
24. Deniz, A.A.; Peters, K.S.; Snyder, G. J. Science 1999, 286, 1119.
25. Broadus, K.M., Kass, S.R. J. Am. Chem. Soc. 2000, 122, 10697.
26. Glukhovtsev, M.N.; Laiter, S.; Pross, A. J. Phys. Chem. 1995, 99, 6828.
27. 8 isomer, spontaneously reverts to the all-Z form, see: Meinwald, J.; Tsuruta, H. J. Am. Chem. Soc. 1970, 92, 2579.
28. Castaño, O.; Notario, R.; Gomperts, R.; Abboud, J.-L.M.; Palmeiro, R.; Andrés, J.L. J. Phys. Chem. A 1998, 102, 4949.
29. The enthalpy of hydrogenation of cyclooctatetraene was directly measured as -409 kJ/mol in Turner, R.B.; Meador, W.R.; Doering, W.V.E.; Knox, L.H.; Mayer, J.R.; Wiley, D.W. J. Am. Chem. Soc. 1957, 79, 4127. However, the reaction was performed in glacial acetic acid, and given the acid sensitivity of this species, we prefer the indirectly obtained value. The enthalpy of formation of cyclooctane is -124.4 ± 1.0 kJ/mol.
30. The enthalpy of formation of(E)-cyclooctene is ca. 40 kJ/mol more positive than that of its (Z)-isomer, see: (a) Turner, R.B.; Meador, W.R. J. Am. Chem. Soc. 1957, 79, 4133.
31. (b) Rogers, D.W.; Von Voithenberg, H.; Allinger, N.L. J. Org. Chem. 1978, 43, 360.
32. (c) Roth, W.R.; Adamczak, O.; Breuckmann, R.; Lennartz, H.-W.; Boese, R. Chem. Ber. 1991, 124, 2499.
33. For a discussion of the strain energy of cycloalkanes, see: Eliel, E.L.; Wilen, S.H. Stereochemistry of Organic Compounds; John Wiley & Sons: New York, 1994. Wiberg, K.B. Angew. Chem., Int. Ed. 1986, 25, 312. Liebman, J.F.; Greenberg, A. Strained Organic Molecules; Academic Press: New York, 1978. New enthalpies of combustion for eight polycyclic compounds are reported in Kolesov, V.P.; Pimenova, S.M.; Lukyanova, V.A.; Kuznetsova, T.S.; Kozina, M.P. J. Chem. Thermodyn. 1998, 30, 1455.
34. For a discussion of the strain energy of cycloalkanes, see: Eliel, E.L.; Wilen, S.H. Stereochemistry of Organic Compounds; John Wiley & Sons: New York, 1994. Wiberg, K.B. Angew. Chem., Int. Ed. 1986, 25, 312. Liebman, J.F.; Greenberg, A. Strained Organic Molecules; Academic Press: New York, 1978. New enthalpies of combustion for eight polycyclic compounds are reported in Kolesov, V.P.; Pimenova, S.M.; Lukyanova, V.A.; Kuznetsova, T.S.; Kozina, M.P. J. Chem. Thermodyn. 1998, 30, 1455.
35. For a discussion of the strain energy of cycloalkanes, see: Eliel, E.L.; Wilen, S.H. Stereochemistry of Organic Compounds; John Wiley & Sons: New York, 1994. Wiberg, K.B. Angew. Chem., Int. Ed. 1986, 25, 312. Liebman, J.F.; Greenberg, A. Strained Organic Molecules; Academic Press: New York, 1978. New enthalpies of combustion for eight polycyclic compounds are reported in Kolesov, V.P.; Pimenova, S.M.; Lukyanova, V.A.; Kuznetsova, T.S.; Kozina, M.P. J. Chem. Thermodyn. 1998, 30, 1455.
36. For a discussion of the strain energy of cycloalkanes, see: Eliel, E.L.; Wilen, S.H. Stereochemistry of Organic Compounds; John Wiley & Sons: New York, 1994. Wiberg, K.B. Angew. Chem., Int. Ed. 1986, 25, 312. Liebman, J.F.; Greenberg, A. Strained Organic Molecules; Academic Press: New York, 1978. New enthalpies of combustion for eight polycyclic compounds are reported in Kolesov, V.P.; Pimenova, S.M.; Lukyanova, V.A.; Kuznetsova, T.S.; Kozina, M.P. J. Chem. Thermodyn. 1998, 30, 1455.
37. Andrés, J.L.; Castaño, O.; Morreale, A.; Palmeiro, R.; Gomperts, R. J. Chem. Phys. 1998, 108, 203.
38. Xie, Y.M.; Schaefer, H.F., III; Liang, G.Y.; Bowen, J.P. J. Am. Chem. Soc. 1994, 116, 1442.
39. Haddon, R.C.; Raghavachari, K.J. J. Am. Chem. Soc. 1985, 107, 289.
40. Sulzbach, H.M.; Schaefer, H.F., III; Klopper, W.; Lüthi, H.P. J. Am. Chem. Soc. 1996, 118, 3519.
41. Tai, J.C.; Allinger, N.L. J. Comput. Chem. 1998, 19, 475.
42. Vogel, E. Isr. J. Chem. 1980, 20, 215.
43. For direct enthalpy of hydrogenation measurements and molecular mechanically calculated enthalpies of formation of hydrogenation products, see: Roth, W.R.; Bohm, M.; Lenhartz, H.-W.; Vogel, E. Angew. Chem. 1983, 95, 1011. Roth, W.R.; Klärner, F.-G.; Siepert, G.; Lennartz, H.-W. Chem. Ber. 1992, 125, 217. The derived enthalpies of formation are 323 and 400 kJ/mol, respectively. For comparison, the enthalpy of formation from combustion measurement of the former is 315 ± 5.8 kJ/ mol (ref 1).
44. For direct enthalpy of hydrogenation measurements and molecular mechanically calculated enthalpies of formation of hydrogenation products, see: Roth, W.R.; Bohm, M.; Lenhartz, H.-W.; Vogel, E. Angew. Chem. 1983, 95, 1011. Roth, W.R.; Klärner, F.-G.; Siepert, G.; Lennartz, H.-W. Chem. Ber. 1992, 125, 217. The derived enthalpies of formation are 323 and 400 kJ/mol, respectively. For comparison, the enthalpy of formation from combustion measurement of the former is 315 ± 5.8 kJ/ mol (ref 1).
45. Vogel, E.; Roth, H.D.Angew. Chem., Int. Ed. Engl. 1964, 3, 228.
46. Dobler, M.; Dunitz, J.D. Helv. Chim. Acta 1965, 48, 1429.
47. George, P.; Glusker, J.P.; Bock, C.W. J. Mol. Struct. (Theochem) 1991, 81, 193.
48. Kiyobayashi, T.; Sakiyama, M.; Sorai, M.; Mitchell, R.H. J. Org. Chem. 1997, 62, 7469.
49. An attempt to derive a difference in the ring strain energies of these species involves cis-bicyclo[4.4.0]decane (decalin) and its [5.3.0]isomer. The difference between their enthalpies of formation is 38.4 kJ/mol, attributable to ring strain. Since there are two such ring systems in each of the annulene derivative isomers, the saturated ring strain is ca. 77 kJ/mol. We will use this quantity as a rough measure of the strain energy in the unsaturated ring system.
50. Nendel, M.; Houk, K.N.; Tolbert, L.M.; Vogel, E., Jiao, H.; Schleyer, P.V.R. J. Phys. Chem. A 1998, 102, 7191.
51. [16]Annulene contains both s-cis and s-trans conjugated double bonds. There are four s-cis and four s-trans diene components in the annulene. The 7.6 kJ/mol correction comes from the hydrogenation enthalpy of the s-cis conjugated double bonds in 1,3-cyclohexadiene. The estimate of the s-trans resonance energy comes from the difference between the enthalpy of hydrogenation of 2,4-hexadiene of -211 + 2 kJ/mol from Fang, W.; Rogers, D.W. J. Org. Chem. 1992, 57, 2294 and the additive enthalpies of hydrogenation of two trans-2-hexenes, -226.4 kJ/mol.
52. (a) Stevenson, C.D.; Kurth, T.L. J. Am. Chem. Soc. 1999, 121, 1623.
53. (b) See also: Oth, J.F.M.; Baumann, H.; Gilles, J.-M.; Schroder, G. J. Am. Chem. Soc. 1972, 94, 3498.
54. Beezer, A.E.; Mortimer, C.T.; Springall, H.D.; Sondheimer, F.; Wolovsky, R. J. Chem. Soc. 1965, 216.
55. (a) Oth, J.F.M.; Bünzli, J.-C.; de Julien de Zélicourt, Y. Helv. Chim. Acta. 1974, 58, 2276.
56. (b) Also, see, Oth, J.F.M.; Gilles, J.-M. J. Phys. Chem. A 2000, 104, 7980.
57. 15 exhibit some degree of angle and/or transannular strain.
58. Gorter, S.; RuttenKeulemans, E.; Krever, M.; Romers, C. Acta Crystallogr, Sect. B 1995, 51, 1036.
59. Schulman, J.M.; Disch, R.L. J. Mol. Struct. (Theochem) 1991, 80, 213.
60. Yoshizawa, K.; Kato, T.; Yamabe, T. J. Phys. Chem. 1996, 100, 5697.
61. Stevenson, C.D.; Kurth, T.L. J. Am. Chem. Soc. 2000, 122, 722.
62. Haddon, R.C.; Raghavachari, K. J. Am. Chem. Soc. 1985, 107, 289.
63. The two-carbon ortho-fusion of benzene rings accounts for this class of compounds being referred to as ortho-condensed. The term cata-condensed arises from the rings being connected in chain or catenary style.
64. Wakayama, N.; Inokuchi, H. Bull. Chem. Soc. Jpn. 1967, 40, 2267.
65. DeKruif, C.G. J. Chem. Thermodyn. 1980, 12, 243.
66. Metzger, R.M.; Kuo, C.S.; Arafat, E.S. J. Chem. Thermodyn. 1983, 15, 841.
67. Coleman, D.J.; Pilcher, G. Trans. Faraday Soc. 1966, 62, 821.
68. Steele, W.V.; Chirico, R.D.; Nguyen, A.; Hossenlopp, I.A.; Smith, N.K. Am. Inst. Chem. Eng. Symp. Ser. (AIChE Symp. Ser), 1990, 138.
69. Chickos, J.S. Personal communication.
70. Nass, K.; Lenoir, D.; Kettrup, A., Angew. Chem., Int. Ed. Engl. 1995, 34, 4, 1735.
71. Westrum, E.F.; Wong, S. Thermodynamik-Symposium Paper II 1967, 10, Heidelberg.
72. Good, W.D. J. Chem. Thermodynam. 1978, 10, 553.
73. Magnus, A.; Hartmann, H.; Becker, F. Z. Phys. Chem. 1951, 197, 75.
74. Cox, J.D.; Pilcher, G. Thermochemistry of Organic and Organometallic Compounds; Academic Press: London and New York, 1970. See also ref 5.
75. Clar, E. The Aromatic Sextet; Wiley: New York, 1972.
76. Annual report #7, p 53, Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, 1986.
77. Wittig, G.; Barendt, E.; Schoch, W. Liebigs Ann. Chem. 1971, 749, 24.
78. Chirico, R.D.; Knipmeyer, S.E.; Nguyen, A.; Smith, N.K.; Steele, W.V.J. Chem. Thermodyn. 1993, 25, 729.
79. Schulman, J.M.; Disch, R.L. J. Phys. Chem. 1997, 101, 9176.
80. Nagano, Y. J. Chem. Thermodyn. 2000, 32, 973.
81. Schleyer, P.V.R.; Maerker, C.; Dransfeld, A.; Jaio, H.; Hommes, N.J.R.V.E. J. Am. Chem. Soc. 1996, 118, 6317.
82. Harvey, R.G. Polycyclic Aromatic Hydrocarbons; Wiley-VCH: New York, 1997.
83. Wiberg, K.B. J. Org. Chem. 1997, 62, 5720.
84. Cyranski, M.K.; Stepien, B.T.; Krygowski, T.M. Tetrahedron 2000, 56, 9663.
85. Cyranski, M.K.; Krygowski, T.M. Tetrahedron 1998, 54, 14919.
86. Howard, S.T.; Krygowski, T.M. Can. J. Chem. 1997, 75, 1174.
87. Herndon, W.C. J. Org. Chem. 1998, 63, 7445.
88. Ribeiro da Silva, M.A.V.; Ferrao, M.L.C.C.H.; Lopes, A.J.M. J. Chem. Thermodyn. 1993, 25, 229.
89. Brown, H.C.; Domash, L. J. Am. Chem. Soc. 1956, 78, 5384 cites the unpublished data from Prosen, E.J.
90. All the isomers in this series were determined by Good, W.D. J. Chem. Thermodyn. 1975, 7, 49.
91. Krygowski, T.M.; Cyranski, M.K. In Advances in Molecular Structure Research; Hargittai, M., Hargittai, I., Eds.; JAI Press: Greenwich, CT, 1997; Vol. 3.
92. Nesterova, T.N.; Verevkin, S.P.; Karaseva, S.Y.; Rozhnov, A.M.; Tsvetkov, V.F. Russ J. Phys. Chem. 1984, 58, 297.
93. Arnett, E.M.; Sanda, J.C.; Bollinger, J.M.; Barber, M. J. Am. Chem. Soc. 1967, 89, 5389.
94. Chickos, J.S.; Hesse, D.G.; Hosseini, S.; Liebman, J.F.; Mendenhall, G.D.; Rakus, K.; Beckhaus, H.-D.; Rüchardt, C. J. Chem. Thermodyn. 1995, 27, 693.
95. Sabbah, R.; Chastel, R.; Lafitte, M. Thermochim. Acta 1974, 10, 353.
96. Good, W.D. J. Chem. Thermodyn. 1973, 5, 715.
97. Colomina, M.; Jiménez, P.; Roux, M.V.; Turrión, C. An. Quim. 1979, 75, 620.
98. Finke, H.L.; Messerly, J.F.; Lee, S.H.; Osborn, A.G.; Douslin, D.R. J. Chem. Thermodyn. 1977, 9, 937.
99. Aihara, A. Bull Chem. Soc. Jpn. 1959, 32, 1242.
100. Chirico, R.D.; Knipmeyer, S.E.; Nguyen, A.; Steele, W.V. J. Chem. Thermodyn. 1993, 25, 1461.
101. Chirico, R.D.; Hossenlopp, I.A.; Nguyen, A.; Steele, W.V.; Gammon, B.E. J. Chem. Thermodyn. 1989, 21, 179.
102. Liebman, J.F.; Slayden, S.W. In Advances in Molecular Structure Research; Hargittai, M., Hargittai, I., Eds.; JAI Press: Greenwich, CT, 1998; Vol. 4.
103. Kane, V.V.; Wolf, A.D.; Jones, M., Jr. J. Am. Chem. Soc. 1974, 96, 2643.
104. Cram, D.J.; Knox, G.R. J. Am. Chem. Soc. 1961, 83, 2204.
105. Jenneskens, L.W.; de Kanter, F.J.J.; Kraakman, P.A.; Turkenburg, L.A.M.; Koolhaas, W.E.; de Wolf, W.H.; Bickelhaupt, F.; Tobe, Y.; Kakiuchi, K.; Odaira, Y. J. Am. Chem. Soc. 1985, 107, 3716.
106. Rice, J.E.; Lee, T.J.; Remington, R.B.; Allen, W.D.; Clabo, D.A.; Schaefer, H.F., III J. Am. Chem. Soc. 1987, 109, 2902.
107. Lee, T.J.; Rice, J.E.; Allen, W.D.; Remington, R.B.; Clabo, D.A.; Schaefer, H.F., III Chem. Phys. 1988, 123, 1.
108. Ma, B.Y.; Sulzbach, H.M.; Remington, R.B.; Schaefer, H.F., III J. Am. Chem. Soc. 1995, 117, 8392.
109. 1H NMR indicated they both retain aromaticity despite distortion.
110. Grimme, S. J. Am. Chem. Soc. 1992, 114, 10542.
111. We thank H. Hopf for suggesting this provocative and evocative [1]-[10]annulenophane description of the bridged annulenes.
112. Shieh, C.-F.; McNally, D.; Boyd, R.H. Tetrahedron 1969, 25, 3653. See also: Boyd, R.H. Tetrahedron 1966, 22, 119.
113. Shieh, C.-F.; McNally, D.; Boyd, R.H. Tetrahedron 1969, 25, 3653. See also: Boyd, R.H. Tetrahedron 1966, 22, 119.
114. The final products from hydrogenolysis of the [m,n]cyclophanes on which the calculations were based are n-butyl benzene and p-n-butyltoluene (estimated from eq 15), p-ethyltohiene, and p-di-n-propylbenzene (estimated from eq 15).
115. For a review of substituted and annelated derivatives, see: Mitchell, R.H. Adv. Theor. Interesting Mol. 1989, 1, 135.
116. Mitchell, R.H.; Iyer, V.S.; Mahadevan, R.; Venugoplan, S.; Zhou, P. J. Org. Chem. 1996, 61, 5116.
117. Dewhirst, K.C.; Cram, D.J. J. Am. Chem. Soc. 1958, 80, 3115.
118. McBride, J.M.; Keehn, P.M.; Wasserman, H.H. Tetrahedron Lett. 1969, 4147.
119. The enthalpy of formation of solid benzene is 38.2 kJ/mol using the enthalpy of sublimation measured by Calado, J.C.R.; Dias, A.R.; Minas da Piedade, M.E.; Martinho Simões, J.A. Rev. Port. Quire. 1980, 22, 53.
120. Ribeiro da Silva, M.A.V.; Mates, M.A.R.; do Rio, C.M.A.; Morals, V.M.F. J. Chem. Soc., Faraday Trans. 1997, 93, 3061. They determined the gaseous and solid enthalpies of formation for 4-methylbiphenyl (138.2 ± 2.9 and 58.0 ± 2.5 kJ/mol, respectively) and for 4, 4'-dimethylbiphenyl (111.3 ± 3.6 and 16.2 ± 2.9 kJ/mol, respectively).
121. Pongratz, A.; Griengl, F.; Gecelsky, L. Sitz. Akad. Wiss. Wien Math. Naturwiss. Kl. Abt. 1932, 2B, 833.
122. Becker, H.-D.; Langer, V.; Sieler, J.; Becker, H.-C. J. Org. Chem. 1992, 57, 1883.
123. Verevkin, S.P. J. Chem. Thermodyn. 1997, 29, 1495. The simple logic based on resonance stabilization and steric repulsion from which we would have concluded the stability order p > m > o is confirmed for the solid terphenyls with a ca. 20 kJ/mol total spread.
124. Balepin, A.A.; Lebedev, V.P.; Miroshnichenko, E.A.; Kolobskii, G.I.; Ostovskii, V.A.; Larionov, B.P.; Gidasapov, B.V.; Lebedev, Y.A. Svoistva Veshchestv. Str. Mol. 1977, 93. These authors also measured the enthalpies of formation and of sublimation of p-terphenyl and found a value of 279 ± 6.3 kJ/mol which, within the error bars, is the same as the value from ref 112.
125. Fawcett, J.K.; Trotter, J. Acta Crystallogr. 1966, 20, 87. Mak, T.C.W.; Trotter, J. J. Chem. Soc. 1962, 1.
126. Fawcett, J.K.; Trotter, J. Acta Crystallogr. 1966, 20, 87. Mak, T.C.W.; Trotter, J. J. Chem. Soc. 1962, 1.
127. Baker, W.; McOmie, J.F.W.; Preston, D.R.; Rogers, V. J. Chem. Soc. 1960, 414.
128. Roux, M.V.; Jiménez, P.; Martin-Luengo, M.A.; Dávalos, J.Z.; Sun, Z.; Hosmane, R.S.; Liebman, J.F. J. Org. Chem. 1997, 62, 2732.
129. The enthalpy of formation of benzocyclobutene is 155.7 ± 0.9 (1) and 199.4 ± 0.9 (g) from Roth, W.R.; Biermann, M.; Dekker, H.; Jochems, R.; Mosselman, C.; Hermann, H. Chem. Ber. 1978, 111, 3892.
130. Eckert-Maksic, M.; Fabian, W.M.F.; Janoschek, R.; Maksic, Z.B. J. Mol. Struct. (Theochem) 1995, 338, 1.
131. n that forced new names here. For a review of the [N]phenylenes, see: Mohler, D.L.; Vollhardt, K.P.C. Adv. Strain Org. Chem. 1996, 5, 121.
132. Beckhaus, H.-D.; Faust, R.; Matzger, A.J.; Mohler, D.L.; Rogers, D.W.; Rüchardt, C.; Sawhney, A.K.; Verevkin, S.P.; Vollhardt, K.P.C.; Wolff K. J. Am. Chem. Soc. 2000, 122, 7819.
133. Schulman, J.M.; Disch, R.L. J. Am. Chem. Soc. 1996, 118, 8470.
134. Schulman, J.M.; Disch, R.L.; Jiao, H.; Schleyer, P.V.R. J. Phys. Chem. A 1998, 102, 8051.
135. Ohta, K.; Shima, T. Chem. Phys. Lett. 1994, 217, 7.
136. Sander, W. Acc. Chem. Res. 1999, 32, 669.
137. Jiao, H.; Schleyer, P.V.R.; Mo, Y.; McAllister, M.A.; Tidwell, T.T. J. Am. Chem. Soc. 1997, 119, 7075.
138. Roth, W.E.; Lennartz, H.W.; Vogel, E.; Leiendecker, M.; Masaji, O. Chem. Ber. 1986, 119, 837.
139. Cremer, D.; Schmidt, T.; Bock, C.W. J. Org. Chem. 1985, 50, 2684.
140. Koseki, S. Kataoka, M.; Hanamura, M.; Nakajima, T. J. Org. Chem. 1984, 49, 2988.
141. Favini, G.; Moro, G.; Todeschini, R.; Simonetta, M. J. Comput. Chem. 1984, 5, 343.
142. To derive this number, we have chosen the archival enthalpy of formation of the solid and the enthalpy of sublimation from ref 131.
143. Chickos, J.S.; Hesse, D.G.; Hosseini, S.; Nichols, G.; Webb, P. Thermochim. Acta 1998, 313, 101.
144. Grimme, S. Chem. Phys. Lett. 1993, 201, 67.
145. For a thermochemical discussion of these species, see: Liebman, J.F. In The Chemistry of Functional Groups: The Chemistry of Dienes and Polyenes; Z. Rappoport, Ed.; Wiley: Chichester, 1997; Vol 1.
146. Falchi, A.; Gellini, C.; Salvi, P.R.; Hafner, K. J. Phys. Chem. 1995, 99, 14659.
147. Zywietz, T.K.; Hiao, H.; Schleyer, P.V.R.; de Meijere, A. J. Org. Chem. 1998, 63, 3417.
148. Two values for the enthalpy of formation of fluorene have recently been reported: 86.7 ± 4.1 (c), 166.9 ± 4.1 (g) from Sabbah, R. Bull Soc. Chim. Fr. 1991, 128, 350 and 89.87 ± 1.40 (c), 175.0 ± 1.5 (g) kJ/mol Rakus, K.; Verevkin, S.P.; Schatzer, J.; Beckhaus, H.-D. Rüchardt, C. Chem. Ber. 1994, 127, 1095.
149. Two values for the enthalpy of formation of fluorene have recently been reported: 86.7 ± 4.1 (c), 166.9 ± 4.1 (g) from Sabbah, R. Bull Soc. Chim. Fr. 1991, 128, 350 and 89.87 ± 1.40 (c), 175.0 ± 1.5 (g) kJ/mol Rakus, K.; Verevkin, S.P.; Schatzer, J.; Beckhaus, H.-D. Rüchardt, C. Chem. Ber. 1994, 127, 1095.
150. Diego, H.P.; Persy, G.; Minas da Piedade, M.E.; Wirz, J. J. Org. Chem. 1996, 61, 6733.
151. Minas da Piedade, M.E. Personal communication.
152. Schulman, J.M.; Disch, R.L. J. Mol. Struct. (Theochem) 1992, 91, 173.
153. Ligabue, A.; Pincelli, U.; Lazzeretti, P.; Zanasi, R. J. Am. Chem. Soc. 1999, 121, 5513.
154. (b) Fowler, P.W.; Steiner, E.; Cadioli, B.; Zanasi, R. J. Phys. Chem. A 1998, 102, 7297.
155. Boekelheide, V.; Turner, R.B.; Linday, W.S. Tetrahedron 1971, 27, 3341.
156. °= 26.0 ± 2.0 kJ/mol) is the identical -124.3 ± 2.5 kJ/mol.
157. See ref 41. In addition, these odd-membered rings are aligned more as found in pentaheptafulvalene and biphenyl than they are like azulene and naphthalene.
158. Hedberg, L.; Hedberg, K.; Cheng, P.C.; Scott, L.T. J. Phys. Chem. A 2000, 104, 7689.
159. Kiyobayashi, T.; Nagano, Y.; Sakiyama, M.; Yamamoto, K.; Cheng, P.-C.; Scott, L.T. J. Am. Chem. Soc. 1995, 117, 3270. The solid-phase enthalpy of formation is 342.3 ± 5.6 kJ/mol from combustion calorimetry measurements. The enthalpy of sublimation is estimated as 121.4 kJ/mol.
160. Biedermann, P.U.; Pogodin, S.; Agranat, I. J. Org. Chem. 1999, 64, 3655.
161. A personal communication quoted in ref 145 from Allinger, N.L.; Nevins, N.; Lii, J.-H.
162. Armitage, D.A.; Bird, C.W. Tetrahedron Lett. 1993, 34, 5811.
163. Braun, T.; Schubert, A.P.; Kostoff, R.N. Chem. Rev. 2000, 100, 23.
164. Eight references on the experimental thermochemistry of fullerenes and 24 references on the theoretical thermochemistry of fullerenes are cited by Minas da Piedade, M.E. In Energetics of Stable Molecules and Reactive Intermediates; Minas da Piedade, M.E., Ed.; NATO ASI Series 535C; Kluwer: Dordrecht, 1999; p 48.
165. See, for example, the exultant article: Beckhaus, H.-D.; Verevkin, S.P.; Rüchardt, C.; Diederich.; Thilgen, C.; ter Meer, U.-H.; Müller, W. Angew. Chem., Int. Ed. Eng. 1994, 33, 996.