53. Jorgensen WL (1975) Chemical consequences of orbital interactions. II. Ethylene and
butadiene bridged polycyclic hydrocarbons containing three- and four-membered rings. J Am
Chem Soc 97:3082–3090
54. Jorgensen WL (1976) The energetic impact of monohomoaromaticity. J Am Chem Soc
98:6784–6789
55. Haddon RC (1974) Homoaromatic, nonhomoaromatic, antihomoaromatic, and
dihomoaromatic character. Tetrahedron Lett 2797–2800
56. Haddon RC (1974) The involvement of the cyclobutane ring in homoaromatic conjugation.
Tetrahedron Lett 15:4303–4304
57. Haddon RC (1975) Perturbational molecular orbital (PMO) theory of homoaromaticity. J Am
Chem Soc 97:3608–3615
58. Hehre WJ (1973) Homoaromatic stability. J Am Chem Soc 95:5807–5809
59. Childs RF, Cremer D, Elia G (1995) Cyclopropyl homoconjugation-experimental facts and
interpretations. In: Rappoport Z (ed) The chemistry of functional groups: the chemistry of the
cyclopropyl group, vol 2. Wiley, Chichester, pp 411–468 and references therein
60. Cremer D, Reichel F, Kraka E (1991) Homotropenylium cation: structure, stability, and
magnetic properties. J Am Chem Soc 113:9459–9466
61. Childs RF (1984) The homotropylium ion and homoaromaticity. Acc Chem Res 17:347–352
62. Williams RV (2001) Homoaromaticity. Chem Rev 101:1185–1204
63. Minkin VI, Glukhovtsev MN, Simkin BY (1994). Homoaromaticity. Aromaticity and
antiaromaticity. Electronic and structural aspects, Chapter 6. Wiley, New York, pp 230–251
64. Reindl B, Clark T, Schleyer PVR (1998) Modern molecular mechanics and ab initio
calculations on benzylic and cyclic delocalized cations. J Phys Chem A 102:8953–8963
65. Alkorta I, Elguero J, Eckert-Maksič M et al (2004) Influence of the H/F replacement on the
homoaromaticity of homotropylium ion: a GIAO/DFT theoretical study. Tetrahedron
60:2259–2265
66. Cremer D, Olsson L, Reichel F et al (1993) Calculation of NMR chemical shifts—the third
dimension of quantum chemistry. Isr J Chem 33:369–385
67. Brown EC, Bader RFW, Werstiuk NH (2009) QTAIM study on the degenerate Cope
rearrangements of 1,5-Hexadiene and Semibullvalene. J Phys Chem A 113:3254–3265
68. Genaev AM, Sal’nikov GE, Shubin VG (2007) Energy barriers to carousel rearrangements of
carbocations: quantum-chemical calculations vs. experiment. Russ J Org Chem 43:1134–1138
69. Barzaghi M, Gatti C (1988) Substituent effect on the planarization energy and the relative
stability of Winstein and Möbius structures of the homotropylium cation. J Mol Struct
(THEOCHEM) 167:275–300
70. Godbout N, Salahub DR, Andzelm J et al (1992) Optimization of Gaussian-type basis sets for
local spin density functional calculations. Part I. Boron through neon, optimization technique
and validation. Can J Chem 70:560–571
71. Frisch MJ, Trucks GW, Schlegel HB et al (2009) Gaussian 09, Revision A.1. Gaussian, Inc.,
Wallingford
72. Gatti C Unpublished result (available upon request)
73. Available from Prof. Bader’s RFW Laboratory. McMaster University, Hamilton, Canada L8S
4M1. http://www.chemistry.mcmaster.ca/aimpac/
74. Cordero B, Gómez V, Platero-Plats AE et al (2008) Covalent radii revisited. Dalton Trans
2832–2838
75. Hill RK, Giberson CB, Silverton JV (1988) Forfeiture of the aromaticity of a Bridged[10]
Annulene by benzannelation. J Am Chem Soc 110:497–500
76. Mitchell RH (2001) Measuring aromaticity by NMR. Chem Rev 101:1301–1316
77. Creary X, Miller KJ (2003) Stabilized and destabilized carbocations in the 1,6-methano[10]
annulene series. J Org Chem 68:8683–8692
78. Creary X, Miller KJ (2002) 1,6-Methano[10]annulene-stabilized radicals. Org Lett 3493–3496
79. Vogel E, Roth HD (1964) Synthese eines cyclodecapentaens. Angew Chem 76:145
80. Bianchi R, Pilati T, Simonetta M (1972) A very long carbon–carbon bond in a cyclopropane
derivative. J Chem Soc Chem Commun 1073–1074
128
C. Gatti et al.
butadiene bridged polycyclic hydrocarbons containing three- and four-membered rings. J Am
Chem Soc 97:3082–3090
54. Jorgensen WL (1976) The energetic impact of monohomoaromaticity. J Am Chem Soc
98:6784–6789
55. Haddon RC (1974) Homoaromatic, nonhomoaromatic, antihomoaromatic, and
dihomoaromatic character. Tetrahedron Lett 2797–2800
56. Haddon RC (1974) The involvement of the cyclobutane ring in homoaromatic conjugation.
Tetrahedron Lett 15:4303–4304
57. Haddon RC (1975) Perturbational molecular orbital (PMO) theory of homoaromaticity. J Am
Chem Soc 97:3608–3615
58. Hehre WJ (1973) Homoaromatic stability. J Am Chem Soc 95:5807–5809
59. Childs RF, Cremer D, Elia G (1995) Cyclopropyl homoconjugation-experimental facts and
interpretations. In: Rappoport Z (ed) The chemistry of functional groups: the chemistry of the
cyclopropyl group, vol 2. Wiley, Chichester, pp 411–468 and references therein
60. Cremer D, Reichel F, Kraka E (1991) Homotropenylium cation: structure, stability, and
magnetic properties. J Am Chem Soc 113:9459–9466
61. Childs RF (1984) The homotropylium ion and homoaromaticity. Acc Chem Res 17:347–352
62. Williams RV (2001) Homoaromaticity. Chem Rev 101:1185–1204
63. Minkin VI, Glukhovtsev MN, Simkin BY (1994). Homoaromaticity. Aromaticity and
antiaromaticity. Electronic and structural aspects, Chapter 6. Wiley, New York, pp 230–251
64. Reindl B, Clark T, Schleyer PVR (1998) Modern molecular mechanics and ab initio
calculations on benzylic and cyclic delocalized cations. J Phys Chem A 102:8953–8963
65. Alkorta I, Elguero J, Eckert-Maksič M et al (2004) Influence of the H/F replacement on the
homoaromaticity of homotropylium ion: a GIAO/DFT theoretical study. Tetrahedron
60:2259–2265
66. Cremer D, Olsson L, Reichel F et al (1993) Calculation of NMR chemical shifts—the third
dimension of quantum chemistry. Isr J Chem 33:369–385
67. Brown EC, Bader RFW, Werstiuk NH (2009) QTAIM study on the degenerate Cope
rearrangements of 1,5-Hexadiene and Semibullvalene. J Phys Chem A 113:3254–3265
68. Genaev AM, Sal’nikov GE, Shubin VG (2007) Energy barriers to carousel rearrangements of
carbocations: quantum-chemical calculations vs. experiment. Russ J Org Chem 43:1134–1138
69. Barzaghi M, Gatti C (1988) Substituent effect on the planarization energy and the relative
stability of Winstein and Möbius structures of the homotropylium cation. J Mol Struct
(THEOCHEM) 167:275–300
70. Godbout N, Salahub DR, Andzelm J et al (1992) Optimization of Gaussian-type basis sets for
local spin density functional calculations. Part I. Boron through neon, optimization technique
and validation. Can J Chem 70:560–571
71. Frisch MJ, Trucks GW, Schlegel HB et al (2009) Gaussian 09, Revision A.1. Gaussian, Inc.,
Wallingford
72. Gatti C Unpublished result (available upon request)
73. Available from Prof. Bader’s RFW Laboratory. McMaster University, Hamilton, Canada L8S
4M1. http://www.chemistry.mcmaster.ca/aimpac/
74. Cordero B, Gómez V, Platero-Plats AE et al (2008) Covalent radii revisited. Dalton Trans
2832–2838
75. Hill RK, Giberson CB, Silverton JV (1988) Forfeiture of the aromaticity of a Bridged[10]
Annulene by benzannelation. J Am Chem Soc 110:497–500
76. Mitchell RH (2001) Measuring aromaticity by NMR. Chem Rev 101:1301–1316
77. Creary X, Miller KJ (2003) Stabilized and destabilized carbocations in the 1,6-methano[10]
annulene series. J Org Chem 68:8683–8692
78. Creary X, Miller KJ (2002) 1,6-Methano[10]annulene-stabilized radicals. Org Lett 3493–3496
79. Vogel E, Roth HD (1964) Synthese eines cyclodecapentaens. Angew Chem 76:145
80. Bianchi R, Pilati T, Simonetta M (1972) A very long carbon–carbon bond in a cyclopropane
derivative. J Chem Soc Chem Commun 1073–1074
128
C. Gatti et al.