38. Zhu J, Fogarty HA, Möllerstedt H, Brink M, Ottosson H (2013) Aromaticity effects on the
profiles of the lowest triplet-state potential-energy surfaces for rotation about the C=C bonds
of olefins with five-membered ring substituents: an example of the impact of Baird’s rule.
Chem Eur J 19:10698–10707
39. Ottosson H, Kilså K, Chajara K, Piqueras MC, Crespo R, Kato H, Muthas D (2007) Scope and
limitations of the Baird’s theory on triplet state aromaticity: application to the tuning of
singlet-triplet energy gaps in fulvene. Chem Eur J 13:6998–7005
40. Möllerstedt H, Piqueras MC, Crespo R, Ottosson H (2004) Fulvenes, fulvalenes, and azulene:
are they aromatic chameleons? J Am Chem Soc 126:13938–13939
41. Soncini A, Fowler PW (2008) Ring-current aromaticity in open-shell systems. Chem Phys Lett
450:431–436
42. Mandado M, Graña AM, Pérez-Juste I (2008) Aromaticity in spin-polarized systems: can rings
be simultaneously alpha aromatic and beta antiaromatic? J Chem Phys 129:164114
43. Karadakov PB (2008) Aromaticity and antiaromaticity in low-lying electronic states of
cyclooctatetraene. J Phys Chem A 112:12707–12713
44. Karadakov PB (2008) Ground- and excited-state aromaticity and antiaromaticity in benzene
and cyclobutadiene. J Phys Chem A 112:7303–7309
45. Matito E, Solà M, Salvador P, Duran M (2007) Electron sharing indexes at the correlated
level. application to aromaticity measures. Faraday Discuss 135:325–345
46. Chen Z, Jiao H, Hirsch A, Thiel W (2001) The 2(N + 1)
2 rule for spherical aromaticity: further
validation. J Mol Model 7:161–163
47. Chen ZF, King R (2005) Spherical aromaticity: recent work on fullerenes, polyhedral boranes,
and related structures. Chem Rev 105:3613–3642
48. Aihara J (1978) Three-dimensional aromaticity of polyhedral boranes. J Am Chem Soc
100:3339–3342
49. Gogonea V, Schleyer PvR, Schreiner PR (1998) Consequences of triplet aromaticity in 4nπelectron annulenes: calculation of magnetic shieldings for open-shell species. Angew Chem Int
Ed 37:1945–1948
50. Lazzeretti P (2000) Ring currents. In: Emsley JW, Feeney J, Sutcliffe LH (eds) Progress in
nuclear magnetic resonance spectroscopy, vol 36. Elsevier, Amsterdam, pp 1–88
51. Lazzeretti P (2004) Assessment of aromaticity via molecular response properties. Phys Chem
Chem Phys 6:217–223
52. Pelloni S, Lazzeretti P (2011) Correlation between the out-of-plane components of
magnetizability and central magnetic shielding in unsaturated cyclic molecules. J Phys
Chem A 115:4553–4557
53. Pelloni S, Lazzeretti P (2013) Polygonal current model: an effective quantifier of aromaticity
on the magnetic criterion. J Phys Chem A 117:9083–9092
54. Pelloni S, Monaco G, Lazzeretti P, Zanasi R (2011) Beyond NICS: estimation of the
magnetotropicity of inorganic unsaturated planar rings. Phys Chem Chem Phys 13:20666–
20672
55. Feixas F, Jiménez-Halla JOC, Matito E, Poater J, Solà M (2007) Is the aromaticity of the
benzene ring in the (η
6
-C 6 H 6 )Cr(CO) 3 complex larger than that of the isolated benzene
molecule? Polish J Chem 81:783–797
56. Osuna S, Poater J, Bofill JM, Alemany P, Solà M (2006) Are nucleus-independent (NICS) and
1
N NMR chemical shifts good indicators of aromaticity in π-stacked polyfluorenes? Chem
Phys Lett 428:191–195
57. Poater J, Bofill JM, Alemany P, Solà M (2006) The role of electron density and magnetic
couplings on the NICS profiles of [2.2] paracyclophane and related species. J Org Chem
71:1700–1702
58. Poater J, Solà M, Viglione RG, Zanasi R (2004) The local aromaticity of the six-membered
rings in pyracylene. A difficult case for the NICS indicator of aromaticity. J Org Chem
69:7537–7542
59. Lipscomb WN (1963) Boron hydrides. W. A. Benjamin, New York
60. Welch AJ (2013) The significance and impact of Wade’s rules. Chem Commun 49:3615–3616
334
F. Feixas et al.
profiles of the lowest triplet-state potential-energy surfaces for rotation about the C=C bonds
of olefins with five-membered ring substituents: an example of the impact of Baird’s rule.
Chem Eur J 19:10698–10707
39. Ottosson H, Kilså K, Chajara K, Piqueras MC, Crespo R, Kato H, Muthas D (2007) Scope and
limitations of the Baird’s theory on triplet state aromaticity: application to the tuning of
singlet-triplet energy gaps in fulvene. Chem Eur J 13:6998–7005
40. Möllerstedt H, Piqueras MC, Crespo R, Ottosson H (2004) Fulvenes, fulvalenes, and azulene:
are they aromatic chameleons? J Am Chem Soc 126:13938–13939
41. Soncini A, Fowler PW (2008) Ring-current aromaticity in open-shell systems. Chem Phys Lett
450:431–436
42. Mandado M, Graña AM, Pérez-Juste I (2008) Aromaticity in spin-polarized systems: can rings
be simultaneously alpha aromatic and beta antiaromatic? J Chem Phys 129:164114
43. Karadakov PB (2008) Aromaticity and antiaromaticity in low-lying electronic states of
cyclooctatetraene. J Phys Chem A 112:12707–12713
44. Karadakov PB (2008) Ground- and excited-state aromaticity and antiaromaticity in benzene
and cyclobutadiene. J Phys Chem A 112:7303–7309
45. Matito E, Solà M, Salvador P, Duran M (2007) Electron sharing indexes at the correlated
level. application to aromaticity measures. Faraday Discuss 135:325–345
46. Chen Z, Jiao H, Hirsch A, Thiel W (2001) The 2(N + 1)
2 rule for spherical aromaticity: further
validation. J Mol Model 7:161–163
47. Chen ZF, King R (2005) Spherical aromaticity: recent work on fullerenes, polyhedral boranes,
and related structures. Chem Rev 105:3613–3642
48. Aihara J (1978) Three-dimensional aromaticity of polyhedral boranes. J Am Chem Soc
100:3339–3342
49. Gogonea V, Schleyer PvR, Schreiner PR (1998) Consequences of triplet aromaticity in 4nπelectron annulenes: calculation of magnetic shieldings for open-shell species. Angew Chem Int
Ed 37:1945–1948
50. Lazzeretti P (2000) Ring currents. In: Emsley JW, Feeney J, Sutcliffe LH (eds) Progress in
nuclear magnetic resonance spectroscopy, vol 36. Elsevier, Amsterdam, pp 1–88
51. Lazzeretti P (2004) Assessment of aromaticity via molecular response properties. Phys Chem
Chem Phys 6:217–223
52. Pelloni S, Lazzeretti P (2011) Correlation between the out-of-plane components of
magnetizability and central magnetic shielding in unsaturated cyclic molecules. J Phys
Chem A 115:4553–4557
53. Pelloni S, Lazzeretti P (2013) Polygonal current model: an effective quantifier of aromaticity
on the magnetic criterion. J Phys Chem A 117:9083–9092
54. Pelloni S, Monaco G, Lazzeretti P, Zanasi R (2011) Beyond NICS: estimation of the
magnetotropicity of inorganic unsaturated planar rings. Phys Chem Chem Phys 13:20666–
20672
55. Feixas F, Jiménez-Halla JOC, Matito E, Poater J, Solà M (2007) Is the aromaticity of the
benzene ring in the (η
6
-C 6 H 6 )Cr(CO) 3 complex larger than that of the isolated benzene
molecule? Polish J Chem 81:783–797
56. Osuna S, Poater J, Bofill JM, Alemany P, Solà M (2006) Are nucleus-independent (NICS) and
1
N NMR chemical shifts good indicators of aromaticity in π-stacked polyfluorenes? Chem
Phys Lett 428:191–195
57. Poater J, Bofill JM, Alemany P, Solà M (2006) The role of electron density and magnetic
couplings on the NICS profiles of [2.2] paracyclophane and related species. J Org Chem
71:1700–1702
58. Poater J, Solà M, Viglione RG, Zanasi R (2004) The local aromaticity of the six-membered
rings in pyracylene. A difficult case for the NICS indicator of aromaticity. J Org Chem
69:7537–7542
59. Lipscomb WN (1963) Boron hydrides. W. A. Benjamin, New York
60. Welch AJ (2013) The significance and impact of Wade’s rules. Chem Commun 49:3615–3616
334
F. Feixas et al.