Tri-, tetra- and pentamers of 9,9'-spirobifluorenes through full ortho-linkage: high triplet-energy pure hydrocarbon host for blue phosphorescent emitter.
4,4'-Dibromo-9,9'-spirobifluorene was first synthesized, and from this intermediate, three fully ortho-linked tri-, tetra-, and pentamers of 9,9'-spirobifluorenes were constructed. The full ortho-linkage impedes the π conjugation of fluorene units, and guarantees their high triplet energies (E(T) = 2.80 eV). A device with the trimer as the first pure hydrocarbon host material for blue phosphor FIrpic shows a maximum current efficiency of 25 cd/A.
Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University, Wuhan 430072, People's Republic of China.
Cong
C
Fan
Yonghua
Y
Chen
Pei
P
Gan
Chuluo
C
Yang
Cheng
C
Zhong
Jingui
J
Qin
Dongge
D
Ma