| abstract |
The present invention relates to a compound of formula (I), characterized in that it is modified by benzimidazol[1,2-a]benzimidazol-5-yl and/or benzimidazol[1,2-a]benzimidazole ‑2,5‑forked group is substituted, and at least one of the substituents B 1 , B 2 , B 3 , B 4 , B 5 , B 6 , B 7 and B 8 represents N; Devices, especially electroluminescent devices. When used as host material for phosphorescent emitters in electroluminescent devices, the compounds of formula I can improve the efficiency, stability, manufacturability or spectral properties of electroluminescent devices. |