Fluorescent organic light emitting elements having high efficiency

1. An organic light-emitting element, comprising a light-emitting layer comprising

i) a compound of formula

 as guest and a host material; or

ii) a compound of formula

 as host and a fluorescent guest material, wherein

R 1 , R 2 , R 3 and R 4 are independently of each other H, D, F, Cl, a C 1 -C 25 alkyl group, a C 1 -C 25 alkoxy group, a C 6 -C 10 aryloxy group, or a donor group of formula

R 5 , R 6 , R 7 , R 8 and R 9 are independently of each other H, D, F, Cl, a C 1 -C 25 alkyl group, a C 1 -C 25 alkoxy group, a C 6 -C 10 aryloxy group, a group of formula

 (Xa), (Xb), or (Xd);

R 1′ , R 2′ , R 3′ and R 4′ are independently of each other H, D, F, Cl, a C 1 -C 25 alkyl group, a C 1 -C 25 alkoxy group, or a C 6 -C 10 aryloxy group; or

R 1 and R 2 together form a group of formula

R 1′ and R 2′ together form a group of formula

R 3 and R 4 together form a group of formula

R 3′ and R 4′ together form a group of formula

R 5 and R 6 together form a group of formula

 and/or

R 8 and R 9 together form a group of formula

A 1 , A 2 , A 3 , A 4 , A 5 , A 6 , A 7 and A 8 are independently of each other H, D, F, Cl, a C 1 -C 25 alkyl group, or a donor group of formula (Xa), (Xb), or (Xd);

A 9 , A 10 , A 11 , A 12 , A 13 , A 14 , A 15 and A 16 are independently of each other H, D, F, Cl, a C 1 -C 25 alkyl group, or a donor group of formula (Xa), (Xb), or (Xd);

X 1 and X 2 are independently of each other a single bond, O, S, N(R 15 ), C(═O), C(R 16 )(R 17 ), B(R 18 ), or Si(R 19 )(R 20 ) and

R 10 , R 11 , R 12 , R 21 and R 21′ are independently of each other H, D, F, Cl, or a C 1 -C 25 alkyl group;

R 15 , R 16 , R 17 , R 18 , R 19 and R 20 are independently of each other H, D, a C 1 -C 25 alkyl group, or a C 6 -C 14 aryl group, which can optionally be substituted by one, or more groups selected from a C 1 -C 25 alkyl group, a C 1 -C 25 alkoxy group and a C 6 -C 10 aryloxy group;

with the proviso that at least one donor group of formula (Xa), (Xb), or (Xd) is present in the compound of formula (I); characterized in that it emits delayed fluorescence.

2. The organic light-emitting element according to claim 1 , wherein

R 1 , R 2 , R 3 , R 4 , R 6 , R 7 , R 8 and R 9 are independently of each other H, a C 1 -C 25 alkyl group, a C 1 -C 25 alkoxy group, a C 6 -C 10 aryloxy group, a donor group of formula

 or

R 1 and R 2 together form a group of formula

 and/or

R 8 and R 9 together form a group of formula

R 5 is H, a C 1 -C 25 alkyl group, a group of formula

 or a donor group of formula (Xa), (Xb), or (Xd);

X 1 and X 2 are independently of each other a single bond, O, S, C(O), N(R 15 ), or C(R 16 )(R 17 ); and

R 10 , R 11 , R 12 , R 21 and R 21′ are independently of each other H, or a C 1 -C 25 alkyl group;

R 15 is a group of formula

R 16 and R 17 are independently of each other H, a C 1 -C 25 alkyl group;

R 22 and R 23 are independently of each other H, a C 1 -C 25 alkyl group, a C 1 -C 25 alkoxy group, or a C 6 -C 10 aryloxy group;

with the proviso that at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 and R 9 is a donor group of formula (Xa), (Xb), or (Xd).

3. The organic light-emitting element according to claim 1 , wherein the compound of formula (I) is a compound of formula

wherein

R 1 and R 2 are independently of each other H, or a C 1 -C 25 alkyl group, or

R 1 and R 2 together form a group of formula

R 3 , R 7 and R 8 are independently of each other H, a C 1 -C 25 alkyl group, or a donor group of formula

R 5 is H, a C 1 -C 25 alkyl group, a group of formula

 or a donor group of formula (Xa), (Xb), or (Xd);

R 9 is H, or

R 8 and R 9 together form a group of formula

X 1 and X 2 are independently of each other a single bond, O, S, N(R 15 ), or C(R 16 )(R 17 );

R 10 , R 11 , R 12 , R 21 and R 21′ are independently of each other H, or a C 1 -C 25 alkyl group;

R 15 is a group of formula

R 16 and R 17 are independently of each other H, a C 1 -C 25 alkyl group;

R 22 and R 23 are independently of each other H, or a C 1 -C 25 alkyl group;

with the proviso that at least one of R 3 , R 5 and R 7 is a donor group of formula (Xa), (Xb), or (Xd).

4. The organic light-emitting element according to claim 3 , wherein the compound of formula (I) is a compound of formula

wherein

R 1 and R 2 are independently of each other H, or a C 1 -C 25 alkyl group, or

R 1 and R 2 together form a group of formula

R 3 is H, a C 1 -C 25 alkyl group, or a donor group of formula

R 7 is H, a C 1 -C 25 alkyl group, or a donor group of formula (Xa), (Xb), or (Xd);

R 8 and R 9 are H, or

R 8 and R 9 together form a group of formula

X 1 and X 2 are independently of each other a single bond, O, S, N(R 15 ), or C(R 16 )(R 17 );

R 10 , R 11 , R 12 , R 21 and R 21′ are independently of each other H, or a C 1 -C 25 alkyl group;

R 15 is a group of formula

R 16 and R 17 are independently of each other H, a C 1 -C 25 alkyl group;

R 22 and R 23 are independently of each other H, or a C 1 -C 25 alkyl group;

with the proviso that at least one of R 3 and R 7 is a donor group of formula (Xa), (Xb), or (Xd).

5. The organic light-emitting element according to claim 3 , wherein the compound of formula (I) is a compound of formula

wherein

R 3 and R 5 are H and R 7 is a donor group of formula

R 3 and R 5 are H and R 7 is a donor group of formula (Xa), (Xb), or (Xd); or

R 3 is a donor group of formula (Xa), (Xb), or (Xd) and R 5 and R 7 are H; or

R 5 is a donor group of formula (Xa), (Xb), or (Xd) and R 3 and R 7 are H; or

R 3 and R 7 are a donor group of formula (Xa), (Xb), or (Xd) and R 5 is H; or

 wherein

R 3 and R 5 are H and R 7 is a donor group of formula (Xa), (Xb), or (Xd); or

R 3 is a donor group of formula (Xa), (Xb), or (Xd) and R 5 and R 7 are H; or

R 5 is a donor group of formula (Xa), (Xb), or (Xd) and R 3 and R 7 are H; or

R 3 and R 7 are a donor group of formula (Xa), (Xb), or (Xd) and R 5 is H; and

X 1 and X 2 are independently of each other a single bond, O, S, N(R 15 ), or C(R 16 )(R 17 );

R 8 and R 9 are H, or

R 8 and R 9 together form a group of formula

R 10 , R 11 , R 12 , R 21 and R 21′ are independently of each other H, or a C 1 -C 25 alkyl group;

R 15 is a group of formula

R 16 and R 17 are independently of each other H, a C 1 -C 25 alkyl group;

R 22 and R 23 are independently of each other H, or a C 1 -C 25 alkyl group.

6. The organic light-emitting element according to claim 5 , wherein the compound of formula (I) is a compound of formula (Ia″), wherein

R 5 , R 8 and R 9 are H;

R 3 is H and R 7 is a donor group of formula

 or

R 3 is a donor group of formula (Xa), (Xb), or (Xd) and R 7 is H; or

R 3 and R 7 are a donor group of formula (Xa), (Xb), or (Xd); or

a compound of formula (Ia″), wherein

R 5 is H;

R 8 and R 9 together form a group of formula

R 3 is H and R 7 is a donor group of formula (Xa), (Xb), or (Xd); or

R 3 is a donor group of formula (Xa), (Xb), or (Xd) and R 7 is H; or

R 3 and R 7 are a donor group of formula (Xa), (Xb), or (Xd); or

a compound of formula (Ia″), wherein

R 3 , R 7 , R 8 and R 9 are H;

R 5 is a donor group of formula (Xa), (Xb), or (Xd); or

a compound of formula (Ia′″), wherein

R 5 , R 8 and R 9 are H;

R 3 is H and R 7 is a donor group of formula (Xa), (Xb), or (Xd); or

R 3 is a donor group of formula (Xa), (Xb), or (Xd) and R 7 is H; or

R 3 and R 7 are a donor group of formula (Xa), (Xb), or (Xd); or

a compound of formula (Ia′″), wherein

R 5 is H;

R 8 and R 9 together form a group of formula

R 3 is H and R 7 is a donor group of formula (Xa), (Xb), or (Xd); or

R 3 is a donor group of formula (Xa), (Xb), or (Xd) and R 7 is H; or

R 3 and R 7 are a donor group of formula (Xa), (Xb), or (Xd); or

a compound of formula (Ia′″), wherein

R 3 , R 7 , R 8 and R 9 are H;

R 5 is a donor group of formula (Xa), (Xb), or (Xd);

X 1 and X 2 are independently of each other a single bond, O, S, N(R 15 ), or C(R 16 )(R 17 );

R 10 , R 11 , R 12 , R 21 and R 21′ are independently of each other H, or a C 1 -C 25 alkyl group;

R 15 is a group of formula

R 16 and R 17 are independently of each other H, a C 1 -C 25 alkyl group;

R 22 and R 23 are independently of each other H, or a C 1 -C 25 alkyl group.

7. The organic light-emitting element according to claim 3 , wherein the compound of formula (I) is a compound of formula

wherein

R 5 is a group of formula

R 7 and R 8 are a donor group of formula

 or

a compound of formula (Ib), wherein

R 5 is a donor group of formula (Xa), (Xb), or (Xd), and

R 7 and R 8 are independently of each other H, or a C 1 -C 25 alkyl group; and

X 1 and X 2 are independently of each other a single bond, O, S, N(R 15 ), or C(R 16 )(R 17 );

R 10 , R 11 , R 12 , R 21 and R 21′ are independently of each other H, or a C 1 -C 25 alkyl group;

R 15 is a group of formula

R 16 and R 17 are independently of each other H, a C 1 -C 25 alkyl group;

R 22 and R 23 are independently of each other H, or a C 1 -C 25 alkyl group.

8. The organic light-emitting element according to claim 1 , wherein the compound of formula (I) is a compound of formula

wherein

R 1 and R 4 are a donor group of formula

 and

X 1 and X 2 are independently of each other a single bond, O, S, N(R 15 ), or C(R 16 )(R 17 );

R 8 and R 9 are H, or

R 8 and R 9 together form a group of formula

R 10 , R 11 , R 12 , R 21 and R 21′ are independently of each other H, or a C 1 -C 25 alkyl group;

R 15 is a group of formula

R 16 and R 17 are independently of each other H, a C 1 -C 25 alkyl group;

R 22 and R 23 are independently of each other H, or a C 1 -C 25 alkyl group.

9. The organic light-emitting element according to claim 1 , wherein the donor group is a donor group of formula (Xa), wherein X 1 is a single bond, O, S, C(CH 3 )(CH 3 ), C(═O),

or a donor group of formula (Xb), wherein X 2 is a single bond and R 12 is H; or a donor group of formula (Xd), wherein R 21 and R 21′ are H.

10. The organic light-emitting element according to claim 1 , wherein the donor group is a group of formula

11. A compound of formula

wherein

R 1 , R 2 , R 3 and R 4 are independently of each other H, D, F, Cl, a C 1 -C 25 alkyl group, a C 1 -C 25 alkoxy group, a C 6 -C 10 aryloxy group, or a donor group of formula

R 5 , R 6 , R 7 , R 8 and R 9 are independently of each other H, D, F, Cl, a C 1 -C 25 alkyl group, a C 1 -C 25 alkoxy group, a C 6 -C 10 aryloxy group, a group of formula

(Xa), (Xb), or (Xd);

R 1′ , R 2′ , R 3′ and R 4′ are independently of each other H, D, F, Cl, a C 1 -C 25 alkyl group, a C 1 -C 25 alkoxy group, or a C 6 -C 10 aryloxy group; or

R 1 and R 2 together form a group of formula

R 1′ and R 2′ together form a group of formula

R 3 and R 4 together form a group of formula

R 3′ and R 4′ together form a group of formula

R 5 and R 6 together form a group of formula

 and/or

R 8 and R 9 together form a group of formula

A 1 , A 2 , A 3 , A 4 , A 5 , A 6 , A 7 and A 8 are independently of each other H, D, F, Cl, a C 1 -C 25 alkyl group, or a donor group of formula (Xa), (Xb), or (Xd);

A 9 , A 10 , A 11 , A 12 , A 13 , A 14 , A 15 and A 16 are independently of each other H, D, F, Cl, a C 1 -C 25 alkyl group, or a donor group of formula (Xa), (Xb), or (Xd);

X 1 and X 2 are independently of each other O, S, N(R 15 ), C(R 16 )(R 17 ), B(R 18 ), or Si(R 19 )(R 20 ) and

R 10 , R 11 , R 12 , R 21 and R 21′ are independently of each other H, D, F, Cl, or a C 1 -C 25 alkyl group;

R 15 , R 16 , R 17 , R 18 , R 19 and R 20 are independently of each other H, a C 1 -C 25 alkyl group, or a C 6 -C 14 aryl group, which can optionally be substituted by one, or more groups selected from a C 1 -C 25 alkyl group, a C 1 -C 25 alkoxy group and a C 6 -C 10 aryloxy group;

with the proviso that at least one donor group of formula (Xa), (Xb), or (Xd) is present in the compound of formula (I).

12. The compound according to claim 11 , wherein

R 1 , R 2 , R 3 , R 4 , R 6 , R 7 , R 8 and R 9 are independently of each other H, a C 1 -C 25 alkyl group, a C 1 -C 25 alkoxy group, a C 6 -C 10 aryloxy group, a donor group of formula

 or

R 1 and R 2 together form a group of formula

 and/or

R 8 and R 9 together form a group of formula

R 5 is H, a C 1 -C 25 alkyl group, a group of formula

 or a donor group of formula (Xa), (Xb), or (Xd);

X 1 and X 2 are independently of each other O, S, N(R 15 ), or C(R 16 )(R 17 ); and

R 10 ,R 11 , R 12 , R 21 and R 21′ are independently of each other H, or a C 1 -C 25 alkyl group;

R 15 is a group of formula

R 16 and R 17 are independently of each other H, a C 1 -C 25 alkyl group;

R 22 and R 23 are independently of each other H, a C 1 -C 25 alkyl group, a C 1 -C 25 alkoxy group, or a C 6 -C 10 aryloxy group;

with the proviso that at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 and R 9 is a donor group of formula (Xa), (Xb), or (Xd).

13. The compound according to claim 11 , wherein the compound of formula (I) is a compound of formula

wherein

R 1 and R 2 are independently of each other H, or a C 1 -C 25 alkyl group, or

R 1 and R 2 together form a group of formula

R 3 , R 7 and R 8 are independently of each other H, a C 1 -C 25 alkyl group, or a donor group of formula

R 5 is H, a C 1 -C 25 alkyl group, a group of formula

 or a donor group of formula (Xa), (Xb), or (Xd);

R 9 is H, or

R 8 and R 9 together form a group of formula

X 1 and X 2 are independently of each other O, S, N(R 15 ), or C(R 16 )(R 17 );

R 10 ,R 11 , R 12 , R 21 and R 21′ are independently of each other H, or a C 1 -C 25 alkyl group;

R 15 is a group of formula

R 16 and R 17 are independently of each other H, a C 1 -C 25 alkyl group;

R 22 and R 23 are independently of each other H, or a C 1 -C 25 alkyl group;

with the proviso that at least one of R 3 , R 5 and R 7 is a donor group of formula (Xa), (Xb), or (Xd).

14. The compound according to claim 13 , which is a compound of formula

wherein

R 1 and R 2 are independently of each other H, or a C 1 -C 25 alkyl group, or

R 1 and R 2 together form a group of formula

R 3 is H, a C 1 -C 25 alkyl group, or a donor group of formula

R 7 is H, a C 1 -C 25 alkyl group, or a donor group of formula (Xa), (Xb), or (Xd);

R 8 and R 9 are H, or

R 8 and R 9 together form a group of formula

X 1 and X 2 are independently of each other O, S, N(R 15 ), or C(R 16 )(R 17 );

R 10 ,R 11 , R 12 , R 21 and R 21′ are independently of each other H, or a C 1 -C 25 alkyl group;

R 15 is a group of formula

R 16 and R 17 are independently of each other H, a C 1 -C 25 alkyl group;

R 22 and R 23 are independently of each other H, or a C 1 -C 25 alkyl group;

with the proviso that at least one of R 3 and R 7 is a donor group of formula (Xa), (Xb), or (Xd).

15. The compound according to claim 13 , which is a compound of formula

wherein

R 3 and R 5 are H and R 7 is a donor group of formula

 or

R 3 is a donor group of formula (Xa), (Xb), or (Xd) and R 5 and R 7 are H; or

R 5 is a donor group of formula (Xa), (Xb), or (Xd) and R 3 and R 7 are H; or

R 3 and R 7 are a donor group of formula (Xa), (Xb), or (Xd) and R 5 is H; or

 wherein

R 3 and R 5 are H and R 7 is a donor group of formula (Xa), (Xb), or (Xd); or

R 3 is a donor group of formula (Xa), (Xb), or (Xd) and R 5 and R 7 are H; or

R 5 is a donor group of formula (Xa), (Xb), or (Xd) and R 3 and R 7 are H; or

R 3 and R 7 are a donor group of formula (Xa), (Xb), or (Xd) and R 5 is H; and

X 1 and X 2 are independently of each other O, S, N(R 15 ), or C(R 16 )(R 17 );

R 8 and R 9 are H, or

R 8 and R 9 together form a group of formula

R 10 ,R 11 , R 12 , R 21 and R 21′ are independently of each other H, or a C 1 -C 25 alkyl group;

R 15 is a group of formula

R 16 and R 17 are independently of each other H, a C 1 -C 25 alkyl group;

R 22 and R 23 are independently of each other H, or a C 1 -C 25 alkyl group.

16. The compound according to claim 15 , wherein the compound of formula (I) is a compound of formula (Ia″), wherein

R 5 , R 8 and R 9 are H;

R 3 is H and R 7 is a donor group of formula

 or

R 3 is a donor group of formula (Xa), (Xb), or (Xd) and R 7 is H; or

R 3 and R 7 are a donor group of formula (Xa), (Xb), or (Xd); or

a compound of formula (Ia′″), wherein

R 5 , R 8 and R 9 are H;

R 3 is H and R 7 is a donor group of formula (Xa), (Xb), or (Xd); or

R 3 is a donor group of formula (Xa), (Xb), or (Xd) and R 7 is H; or

R 3 and R 7 are a donor group of formula (Xa), (Xb), or (Xd) and

X 1 and X 2 are independently of each other O, S, N(R 15 ), or C(R 16 )(R 17 );

R 10 ,R 11 , R 12 , R 21 and R 21′ are independently of each other H, or a C 1 -C 25 alkyl group;

R 15 is a group of formula

R 16 and R 17 are independently of each other H, or a C 1 -C 25 alkyl group;

R 22 and R 23 are independently of each other H, or a C 1 -C 25 alkyl group.

17. The compound according to claim 13 , wherein the compound of formula (I) is a compound of formula

wherein

R 5 is a group of formula

R 7 and R 8 are a donor group of formula

 or

a compound of formula (Ib), wherein

R 5 is a donor group of formula (Xa), (Xb), or (Xd), and

R 7 and R 8 are independently of each other H, or a C 1 -C 25 alkyl group; and

X 1 and X 2 are independently of each other O, S, N(R 15 ), or C(R 16 )(R 17 );

R 10 ,R 11 , R 12 , R 21 and R 21′ are independently of each other H, or a C 1 -C 25 alkyl group;

R 15 is a group of formula

R 16 and R 17 are independently of each other H, a C 1 -C 25 alkyl group;

R 22 and R 23 are independently of each other H, or a C 1 -C 25 alkyl group.

18. The compound according to claim 11 , wherein the compound of formula (I) is a compound of formula

wherein

R 1 and R 4 are a donor group of formula

 and

X 1 and X 2 are independently of each other O, S, N(R 15 ), or C(R 16 )(R 17 );

R 8 and R 9 are H, or

R 8 and R 9 together form a group of formula

R 10 ,R 11 , R 12 , R 21 and R 21′ are independently of each other H, or a C 1 -C 25 alkyl group;

R 15 is a group of formula

R 16 and R 17 are independently of each other H, a C 1 -C 25 alkyl group;

R 22 and R 23 are independently of each other H, or a C 1 -C 25 alkyl group.

19. The compound according to claim 11 , wherein the donor group is a donor group of formula (Xa), wherein X 1 is O, S, C(CH 3 )(CH 3 ), C(═O),

or a donor group of formula (Xb), wherein X 2 is a single bond and R 12 is H; or a donor group of formula (Xd), wherein R 21 and R 21′ are H.

20. The compound according to claim 11 , wherein the donor group is a group of formula

21. A light-emitting layer comprising the compound according to claim 11 .

22. An organic light emitting element, comprising the compound according to claim 11 .