Superphenalene Explained

Superphenalene is a very large polycyclic aromatic hydrocarbon (PAH) with chemical formula C₉₆H₃₀. It can be formally considered to consist of three fused superbenzenes (hexa-peri-hexabenzocoronene).^[1]

It can be considered as an overlapping structure of three hexa-peri-hexabenzocoronenes arranged symmetrically around a center.^{[2] [3]} These have also been known as building blocks of molecular electronics since 2004 as they form self-assembling columns and nanotubes.^[4]

It and its hexa-tert-butyl derivative were first prepared in 1997, along with a collection of other very large PAHs. Due to the low solubility of these compounds, they could only be characterized by mass spectrometry when they were first synthesized, as neither NMR nor UV-Vis data could be collected.^[5]

Occurrence

It is not known to occur naturally.

Properties

Superphenalene has a planar geometry. With 540,000 mesomeric boundary structures, it has significantly more than hexabenzocoronene (250), supernaphthalene (16,100) and also buckminsterfullerene (12,500). The molecule has a threefold symmetry axis perpendicular to the molecule (C₃).

Notes and References

1. Randić. Milan. Gao. Xiaofeng. 1999. Giant benzenoid hydrocarbons. Superphenalene resonance energy. New Journal of Chemistry. 23. 2. 251–260. 10.1039/A808949C.
2. 10.1021/ja000850e . Bishexa-peri-hexabenzocoronenyl: A 'superbiphenyl' . Journal of the American Chemical Society . 122 . 32 . 7698–7706 . 2000 . Ito . Shunji . Herwig . Peter Tobias . Böhme . Thilo . Rabe . Jürgen P. . Rettig . Wolfgang . Müllen . Klaus .
3. 10.1021/jo0490301. 15549787. Oligomers of hexa-peri-hexabenzocoronenes as 'super-oligophenylenes': Synthesis, electronic properties, and self-assembly. The Journal of Organic Chemistry. 69. 24. 8194–8204. 2004. Wu. Jishan. Watson. Mark D.. Tchebotareva. Natalia. Wang. Zhaohui. Müllen. Klaus.
4. 10.1126/science.1097789 . 15178796 . Self-assembled hexa-peri-hexabenzocoronene graphitic nanotube . Science . 304 . 5676 . 1481–1483 . 2004 . Hill . J. P. . Jin . W. . Kosaka . A. . Fukushima . T. . Ichihara . H. . Shimomura . T. . Ito . K. . Hashizume . T. . Ishii . N. . Aida . T. . 2004Sci...304.1481H . 39674411 .
5. Iyer . Vivekanantan S. . Wehmeier . Mike . Brand . J. Diedrich . Keegstra . Menno A. . Müllen . Klaus . 1997-08-18 . From Hexa‐ peri ‐hexabenzocoronene to “Superacenes” . Angewandte Chemie International Edition in English . en . 36 . 15 . 1604–1607 . 10.1002/anie.199716041 . 0570-0833.