9,10,11,20,21,22-Hexaphenyltetrabenzo[a,c,l,n]pentacene
This is 9,10,11,20,21,22-hexaphenyltetrabenzo[a,c,l,n]pentacene, the most
highly twisted polycyclic aromatic hydrocarbon ever prepared. Its X-ray
structure shows an end-to-end twist of 144°. Unlike similar molecules
that we have prepared previously, this hydrocarbon is resolvable into pure
enantiomers with specific rotations of plus and minus 7400°! For a
brief communication describing the synthesis and structure of this compound,
see "A Pentacene with a 144° Twist," J. Lu, D. M. Ho, N. J. Vogelaar,
C. M. Kraml, and R. A. Pascal, Jr., J. Am. Chem. Soc. 2004,
126, 11168-11169.