名称:
Tri-, Tetra- and Pentamers of 9,9′-Spirobifluorenes through Fullortho-Linkage: High Triplet-Energy Pure Hydrocarbon Host for Blue Phosphorescent Emitter
摘要:
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 pi conjugation of fluorene units, and guarantees their high triplet energies (Er = 2.80 eV). A device with the trimer as the first pure hydrocarbon host material for blue phosphor Flrpic shows a maximum current efficiency of 25 cd/A.