Invited Lecture – Jay S. Siegel

The formula C_10nH₁₀ includes a series of bowl-shaped carbon-rich structures where in corannulene (1) represents n=2, and the simplest capped nanotube, C₄₀H₁₀ (2), represents n=4.¹ Derivatives of class n=2 continue to lead to many interesting materials.² The class of n=4 is also represented by an isomeric structure of 2, decaethynylcorannulene (3). A simple bond energy estimate for the energetics of 3 compared to 2 results in a remarkable value of 300-400 kcal/mol in favor of 2, and could lead one to question the feasibility for 3 to be isolated as an inert material. From decachlorocorannulene (4), decapentynylcorannulene (5) can be prepared with the hope of making decapropyl-2 (6). Such an approach would open a solution phase method to the synthesis of mono-disperse single-walled carbon nanotubes.3 At the same time, corannulene mono-layers on metals reveal new surface phenomena regarding molecular organization and polymorphism.⁴ Sym-pentakisarylalkynylcorannulenes offer a different type of materials application in the area of oriented solids and liquid crystals with efficient fluorescence activity.⁵

1. Baldridge, K. K.; Siegel, J. S. Theoret. Chem. Acc. 1997, 97, 67. 
2. Wu, Y.-T.; Siegel, J. S. Chem. Rev. 2006, 106, 4843.  
3. Hayama, T.; Wu, Y.-T. Linden, A.; Baldridge, K. K.; Siegel, J. S. J. Am. Chem Soc. 2007, 129, 12612.  
4. Parschau, M.; Fasel, R.; Ernst, K.-H.; Gröning, O.; Brandenberger, L.; Schillinger, R.; Greber, T.; Seitsonen, A. P.; Wu, Y.-T.; Siegel, J. S. Angew. Chem. Int. Ed. 2007, 46, 8258.  
5. Wu, Y.-T.; Bandera, D.; Maag, R.; Linden, A.; Baldridge, K. K.; Siegel, J. S. J. Am. Chem. Soc. 2008 in press.