title: Perfluorophenyl-phenyl interactions in the crystallization and topochemical polymerization of triacetylene monomers.
abstract: A series of symmetrically and unsymmetrically substituted octa-2,4,6-triyne-1,8-diol derivatives with benzoyl, 4-dodecyloxybenzoyl, as well as perfluorobenzoyl substituents were prepared and investigated with respect to their crystal structures and topochemical polymerizability. Single-crystal structures for several of these triacetylene monomers have been obtained and proved that the perfluorophenyl-phenyl interactions played a decisive role in the molecular packing. As a consequence of the geometric requirements imposed by the perfluorophenyl-phenyl interactions, packing parameters appropriate for a topochemical triacetylene polymerization in the sense of either a 1,6- or a 1,4-polyaddition along different crystallographic axes were observed in two cases, and UV irradiation led to successful polymerization. Raman as well as solid-state (13)C NMR spectra of the obtained polymers revealed that the polymerization had predominantly proceeded in the form of a 1,4-polyaddition.
authors.affiliation: ETH Zürich, Department of Materials, Wolfgang-Pauli-Strasse 10, HCI H520, CH-8093 Zürich, Switzerland.
authors.forename: Rui
authors.initials: R
authors.lastname: Xu
authors.forename: W Bernd
authors.initials: WB
authors.lastname: Schweizer
authors.forename: Holger
authors.initials: H
authors.lastname: Frauenrath