摘要 |
Compounds of formula I may be used in optoelectronic devices wherein R1, R2 and R4 are, independently at each occurrence, H, a C1-C20 aliphatic radical, a C3-C20 aromatic radical, or a C3-C20 cycloaliphatic radical; R3 is H or a is, independently at each occurrence, 1 or 2; b is, independently at each occurrence, an integer ranging from 0-3; c is, independently at each occurrence, an integer ranging from 0-4; Ar is independently at each occurrence, H, or heteroaryl; and at least two of Ar are heteroaryl. |