| abstract |
Compositions comprising at least one phosphorescent organometallic compound and a polymer comprising structural units of formula II are useful in organic light emitting devices n n n n n n n n n n n n wherein R 1 , R 2 , and R 4 are independently at each occurrence a C 1 -C 20 aliphatic radical, a C 3 -C 20 aromatic radical, or a C 3 -C 20 cycloaliphatic radical;n nwherein R 3 and R 5 are independently selected from the group consisting of hydrogen, triphenylsilyl, t-butyl, mesityl, diphenyl phosphine oxide, and diphenyl phosphine sulfide; and a, b and d are independently 0 or an integer ranging from 1 to 3. |