title: Novel chiral macrocycles containing two electronically interacting arylene chromophores.
abstract: Novel chiral macrocycles consisting of two rigid oligoarylene rods and two chiral spiroindane clips have been synthesized by condensation of spiroindane diols and CF3-activated alpha-omega-difluorooligoaryls. Since a broad variety of planar aromatic macrocycles is known, our non-planar, chiral rings represent a new class of macrocyclic compounds. The first two examples, which contain quaterphenylene and diphenylbithiophene rods, are presented in this communication; for one of them a crystal structure is given. The chiroptical properties of the macrocycles can be interpreted as an interplay of the "intra-rod" helicity of individual oligoarylene rods and the "inter-rod" helicity between both chromophores of the macrocycle. The macrocycles can act as chiral dopands of commercially available, and novel, polymeric nematic liquid crystals (emissive polyfluorenes). The "intra-rod" helicity of individual oligoarylene rods is the main feature in determining the resulting helical twisting power (HTP). The cholestric induction in mesogenic, emissive polyfluorenes is of special interest for a realization of electronic devices that have a circularly polarized electroluminescence. The results are also important for an understanding of larger ensembles of chiral rodlike molecules, especially their pi-pi interactions.
authors.affiliation: Institut für Chemie der Universität Potsdam, Golm, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Köhler
authors.forename: V
authors.initials: V
authors.lastname: Enkelmann
authors.forename: M
authors.initials: M
authors.lastname: Oda
authors.forename: S
authors.initials: S
authors.lastname: Pieraccini
authors.forename: G P
authors.initials: GP
authors.lastname: Spada
authors.forename: U
authors.initials: U
authors.lastname: Scherf