title: Hexa-peri-hexabenzocoronenes by efficient oxidative cyclodehydrogenation: the role of the oligophenylene precursors.
abstract: [reaction: see text] Oligophenylene precursors based on 1,3,5-tris-(2'-biphenyl)ylbenzene (4a) and 1,4-bis-(2'-biphenyl)yl-2,5-diphenylbenzene (5a) were prepared and utilized for efficient hexabenzocoronene (HBC) synthesis by cyclodehydrogenations. Parent HBC 6a was efficiently synthesized from the 1,3,5-tris-(2'-biphenyl)ylbenzene precursor, and novel D(3)(h)() symmetrical HBCs were prepared from 1,3,5-tris-(2'-biphenyl)ylbenzenes with various substitution types. For the preparation of a tert-butyl containing HBC 7 with D(2)(h)() symmetry, a two-step cyclodehydrogenation was required because of changes in the spin density distribution.
authors.affiliation: Max-Planck Institut für Polymerforschung, Ackermannweg 10, 55128, Mainz, Germany.
authors.forename: Xinliang
authors.initials: X
authors.lastname: Feng
authors.forename: Jishan
authors.initials: J
authors.lastname: Wu
authors.forename: Volk
authors.initials: V
authors.lastname: Enkelmann
authors.forename: Klaus
authors.initials: K
authors.lastname: Müllen