Efficient synthesis of a novel, twisted and stable, electroluminescent "twistacene".
[reaction: see text] A twistacene, 6,8,15,17-tetraphenyl-1.18,4.5,9.10,13.14-tetrabenzoheptacene (3), was synthesized using a mild and novel bisbenzyne precursor. It was characterized by X-ray crystallography, NMR, UV-vis, and IR spectroscopies, as well as cyclic voltammetry and DFT calculations. The heptacene derivative possesses a nonpropeller twist topology and is unusually stable for a highly conjugated oligoacene. In addition, it is fluorescent, with a quantum efficiency of 15%. Distortion from planarity, mostly due to the phenyl substituents, causes only marginal changes in electronic properties and is beneficial for redox reversibility, which is required for efficient OLED devices.
Exotic Materials Institute, Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, USA.
Hieu M
HM
Duong
Michael
M
Bendikov
Daniel
D
Steiger
Qichun
Q
Zhang
Gursel
G
Sonmez
Jeffrey
J
Yamada
Fred
F
Wudl