Structural organization of pi conjugated highly luminescent molecular material.
We report on striking evidence for a room temperature structural phase instability in p-hexaphenyl, inducing a nonplanar conformation of the molecules. Solid state proton NMR and single crystal x-ray diffraction allow the analysis of the organization, the individual dynamics and the involved symmetry breaking. The analysis of Raman spectra above and below room temperature reveals a singular behavior suggesting a modification of the overlap between the electronic wave function induced by the nonplanarity. These results provide a new basis to answer fundamental issues related to molecular and electronic materials and, in particular, luminescent organic devices.
Toudic
B
B
Groupe Matière Condensée et Matériaux, UMR CNRS 6626, Université de Rennes I, 35042 Rennes, France.
Limelette
P
P
Froyer
G
G
Le Gac
F
F
Moréac
A
A
Rabiller
P
P