Patent ID: 8415031

Claim:
A compound having the formula Ar(LiDi)n, wherein Ar contains a condensed aromatic ring system having at least three benzene rings and the condensed aromatic ring has a triplet energy lower than 440 nm; wherein Ar is unsubstituted or substituted with one or more groups selected from the group consisting of hydrogen, deuterium, alkyl, alkoxy, amino, silyl, cyano, halogen, and aryl; wherein L is a single bond or a bivalent linking group; wherein n is at least 1; wherein i is an indexing variable that identifies n structures for L i and D i that may be the same or different for different values of i; wherein each L i is independently a single bond or a bivalent linking group; wherein each D i independently has the structure; wherein X 5 is O, S or Se; where each of X 1 , X 2 , X 3 , X 4 , X 6 , X 7 , X 8 , and X 9 is independently selected from C(R) or N; wherein at least one of X 1 , X 2 , X 3 , X 4 , X 6 , X 7 , X 8 , and X 9 is N; wherein each R is independently selected from the group consisting of hydrogen, deuterium, alkyl, alkoxy, amino, silyl, cyano, halogen, aryl, and heteroaryl; and wherein R is optionally bound to L.