| abstract |
A compound represented by Formula (I) or (II). Formula (I) wherein A is a single bond or a divalent residue of biphenyl, triphenyl, (a), (b), (c) and (d) in each of which one or more hydrogen atoms attached in the carbon atoms may be replaced by a substituent other than hydrogen, wherein Z is any one selected from N, O, S, and SiR, Y is N-R, O, S, Si(R)2 where R is C1-20 alkyl or aryl, R1 and R2 are independently selected from hydrogen or C1-20 alkyl; X1 to X4 are independently selected from substituents other than spirobifluorenyl, A, B1 or B2; 1, p and q are integers of from 0 to 4; m is an integer of from 0 to 3, Formula (II) wherein B1 and B2 are independently selected from hydrogen and a heterocyclic group; r is an integer of from 0 to 3; and X1 to X4, m, p, and q are as defined in Formula (I), with the proviso that B1 and B2 are not hydrogen simultaneously. The use of such compounds in OLEDs is also claimed. |