Connecting pi-chromophores by sigma-P-P bonds: new type of assemblies exhibiting sigma-pi-conjugation.
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.
Fave
Claire
C
Institut de Chimie de Rennes, UMR 6509, CNRS-Université de Rennes1, Campus de Beaulieu, 35042 Rennes, France.
Hissler
Muriel
M
Kárpáti
Tamás
T
Rault-Berthelot
Joëlle
J
Deborde
Valérie
V
Toupet
Loic
L
Nyulászi
László
L
Réau
Régis
R