| 摘要 |
In OLEDs, improved efficiency is obtained by compounds which can form inter alia electron injection layers of the formula (I);whereinR1 is a 1-5 ring aryl (including polycyclic), aralkyl or heteroaryl group which is optionally substituted with one or more C1-C4 alkyl, alkoxy or cyano;R2 and R3 together form a 1-5 ring aryl (including polycyclic), aralkyl or heteroaryl group which is optionally substituted with C1-C4 alkyl, alkoxy or cyano;R4 is hydrogen, C1-C4 alkyl or aryl; andAr is monocyclic, bicyclic or tricyclic aryl or heteroaryl which is optionally substituted with one or more C1-C4-alkyl or alkoxy groups,or an oligomer thereof. |
