title: Centrohexaindane: six benzene rings mutually fixed in three dimensions - solid-state structure and six-fold nitration.
abstract: The solid-state molecular structure of centrohexaindane (), a unique hydrocarbon comprising six benzene rings clamped to each other in three dimensions around a neopentane core, and the molecular packing in crystals of ·CHCl3 are reported. The molecular Td-symmetry and the Cartesian orientation of the six indane wings of in the solid state have been confirmed. The course and limitation of electrophilic aromatic substitution of are demonstrated for the case of nitration. Based on nitration experiments of a lower congener of , tribenzotriquinacene , the six-fold nitrofunctionalisation of has been achieved in excellent yield, giving four constitutional isomers, two nonsymmetrical ( and ) and two C3-symmetrical ones ( and ), all of which contain one single nitro group in each of the six benzene rings. The relative yields of the four isomers (∼3 : 1 : 1 : 3) point to a random electrophilic attack of the electrophiles at the twelve formally equivalent outer positions of the aromatic periphery of , suggesting electronic independence of its six aromatic π-electron systems. In turn, the pronounced conformational rigidity of the centrohexacyclic framework of enables the unequivocal structural identification of the isomeric hexanitrocentrohexaindanes by (1)H NMR spectroscopy.
authors.affiliation: Department of Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany. dietmar.kuck@uni-bielefeld.de and Center for Molecular Materials (CM2), Universitätsstraße 25, 33615 Bielefeld, Germany.
authors.forename: Dietmar
authors.initials: D
authors.lastname: Kuck
authors.affiliation: Department of Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany. dietmar.kuck@uni-bielefeld.de.
authors.forename: Jens
authors.initials: J
authors.lastname: Linke
authors.affiliation: Department of Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany. dietmar.kuck@uni-bielefeld.de.
authors.forename: Lisa Christin
authors.initials: LC
authors.lastname: Teichmann
authors.affiliation: Department of Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany. dietmar.kuck@uni-bielefeld.de.
authors.forename: Dieter
authors.initials: D
authors.lastname: Barth
authors.affiliation: Department of Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany. dietmar.kuck@uni-bielefeld.de.
authors.forename: Jörg
authors.initials: J
authors.lastname: Tellenbröker
authors.affiliation: Department of Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany. dietmar.kuck@uni-bielefeld.de.
authors.forename: Detlef
authors.initials: D
authors.lastname: Gestmann
authors.affiliation: Department of Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany. dietmar.kuck@uni-bielefeld.de.
authors.forename: Beate
authors.initials: B
authors.lastname: Neumann
authors.affiliation: Department of Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany. dietmar.kuck@uni-bielefeld.de.
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Stammler
authors.affiliation: Department of Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany. dietmar.kuck@uni-bielefeld.de.
authors.forename: Hartmut
authors.initials: H
authors.lastname: Bögge