2,5-linked polyfluorenes for optoelectronic devices
View Patent ↗Polyfluorene polymers and copolymers having substantial amounts (10-100%) of fluorenes coupled at the 2 and 5 positions of fluorene are useful as active layers in OLED devices where triplet energies >2.10 eV are required.
1. An oligomer comprising > about 50% by weight of structural units derived from at least one compound of formula I
wherein R 1 and R 2 are independently at each occurrence H, C 1-20 hydrocarbyl, C 1-20 hydrocarbyl containing one or more S, N, O, P or Si atoms, C 4-16 hydrocarbyl carbonyloxy, C 4-16 aryl(trialkylsiloxy) or R 1 and R 2 taken together with an intervening carbon atom form a C 6-20 hydrocarbyl ring or a C 4-20 hydrocarbyl ring containing at least one S, N or O heteroatom;
R 3 and R 4 are independently at each occurrence H, C 1-20 hydrocarbyl, C 1-20 hydrocarbyloxy, C 1-20 thioether, C 1-20 hydrocarbylcarbonyloxy or cyano;
X is independently at each occurrence halo, triflate, —B(OH) 2 , —B(OR) 2 , —BO 2 R, or a combination thereof;
R is alkyl or alkylene; and
a and b are independently 0 or 1.
2. An oligomer according to claim 1 , wherein X is halo.
3. An oligomer according to claim 1 , wherein X is bromo.
4. An oligomer according to claim 1 , wherein X is —B(OH) 2 , —B(OR) 2 , or —BO 2 R.
5. An oligomer according to claim 1 , wherein R 3 and R 4 are H.
6. An oligomer according to claim 1 , wherein R 1 and R 2 are alkyl, substituted alkyl, aryl, substituted aryl, heteroaryl, or substituted heteroaryl.
7. An oligomer according to claim 1 , wherein R 1 and R 2 are alkoxyphenyl.
8. An oligomer according to claim 1 , wherein R 1 and R 2 are alkyl.
9. An oligomer according to claim 1 , comprising fewer than about 10 of the structural units, assembled in a head-to-tail configuration.
10. An oligomer according to claim 1 , additionally comprising end units derived from a compound of formula
11. An oligomer according to claim 1 , additionally comprising structural units derived from a compound of formula III
12. An oligomer having the formula
13. An oligomer comprising > about 50% by weight of structural units derived from at least one compound of formula II
wherein R 1 and R 2 are independently at each occurrence H, C 1-20 hydrocarbyl, C 1-20 hydrocarbyl containing one or more S, N, O, P or Si atoms, C 4-16 hydrocarbyl carbonyloxy, C 4-16 aryl(trialkylsiloxy) or R 1 and R 2 taken together with an intervening carbon atom form a C 6-20 hydrocarbyl ring or a C 4-20 hydrocarbyl ring containing at least one S, N or O heteroatom;
R 3 and R 4 are independently at each occurrence H, C 1-20 hydrocarbyl, C 1-20 hydrocarbyloxy, C 1-20 thioether, C 1-20 hydrocarbylcarbonyloxy or cyano;
one of X and Y is halo or triflate and the other one of X and Y is —B(OH) 2 , —B(OR) 2 , or —BO 2 R;
R is alkyl or alkylene; and
a and b are independently 0 or 1.
14. An oligomer according to claim 13 , wherein one of X and Y is bromo and the other one of X and Y is —BO 2 R.
15. An oligomer according to claim 13 , wherein the compound of formula II is
16. An oligomer according to claim 13 , comprising fewer than about 10 of the structural units, assembled in a head-to-tail configuration.
17. An oligomer according to claim 13 , comprising a single structural unit derived from a compound of formula II.
18. An oligomer according to claim 13 , additionally comprising end units of formula
19. An oligomer according to claim 13 , additionally comprising structural units derived from a compound of formula III
20. An oligomer according to claim 1 , comprising a single structural unit derived from a compound of formula I.