title: Connecting pi-chromophores by sigma-P-P bonds: new type of assemblies exhibiting sigma-pi-conjugation.
abstract: To study the ability of sigma-P-P skeleton to mediate interaction between pi-chromophores, 1,1'-biphospholes bearing phenyl or thienyl substituents at the 2,2' and 5,5'-position have been prepared and studied. These air-stable derivatives are readily available via a "one-pot" synthesis starting from diynes. Theoretical studies and UV-vis data clearly establish that the two pi-systems interact via the sigma-P-P bridge. This through-bond interaction results in a lowering of the optical HOMO-LUMO gap of the assemblies. The nucleophilic sigma(3)-P centers of these 1,1'-biphospholes allow chemical modifications of the sigma-bridge. These modifications offer further tuning of the optical properties of the assembly. Electrooxidation of the thienyl-substituted 1,1'-biphosphole results in electroactive materials characterized by low optical band gap and reversible p-doping.
authors.affiliation: Institut de Chimie de Rennes, UMR 6509, CNRS-Université de Rennes1, Campus de Beaulieu, 35042 Rennes, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Fave
authors.forename: Muriel
authors.initials: M
authors.lastname: Hissler
authors.forename: Tamás
authors.initials: T
authors.lastname: Kárpáti
authors.forename: Joëlle
authors.initials: J
authors.lastname: Rault-Berthelot
authors.forename: Valérie
authors.initials: V
authors.lastname: Deborde
authors.forename: Loic
authors.initials: L
authors.lastname: Toupet
authors.forename: László
authors.initials: L
authors.lastname: Nyulászi
authors.forename: Régis
authors.initials: R
authors.lastname: Réau