THE ALBATROSSENES - LARGE, CLEFT-CONTAINING, POLYPHENYL POLYCYCLIC AROMATIC-HYDROCARBONS

The syntheses and X-ray structures of very Large polycyclic aromatic c ompounds containing clefts defined by polyphenylaryl groups are descri bed. The C-2-symmetric ''albatrossenes'' 1,3-bis(heptaphenyl-2-naphthy l)benzene (7a) and 1,3-bis(heptaphenyl-1-naphthyl)benzene (12a), as we ll as brominated derivatives, were synthesized by the addition of tetr aphenylbenzyne to the appropriate polyphenyl biscyclopentadienones. Th e 2-naphthyl isomers have wide, shallow clefts, and the 1-naphthyl iso mers have deep, narrow clefts which were observed to change size drama tically in different crystal environments. In a similar way, 1,3,5-tri s(pentaphenylphenyl)benzene (19), a D-3-symmetric molecular propeller with a diameter of 21 Angstrom, and 1,3,5-tris(heptaphenyl-2-naphthyl) benzene (22) were prepared by the addition of diphenylacetylene and te traphenylbenzyne, respectively, to a triscyclopentadienone.