Organic electroluminescent devices comprising host compounds

1. An organic compound H of Formula (I):

wherein:

each of X′ 1 and X′ 2 is independently from another selected from the group consisting of N and CR Tz ;

R Tz is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, CN, CF 3 , C 1 -C 20 -alkyl, C 6 -C 18 -aryl, and C 7 -C 19 -alkaryl and, wherein C 6 -C 18 -aryl or C 7 -C 19 -alkaryl can at each occurrence be optionally substituted by a residue selected from the group consisting of C 1 -C 20 -alkyl, C 7 -C 19 -alkaryl, and C 6 -C 18 -aryl;

R′ 1 , R′ 2 , R′ 3 , R′ 4 , R′ 5 , R′ 6 , R′ 7 , R′ 8 , R′ 9 , and R′ 10 is independently from another selected from the group consisting of hydrogen, deuterium, CN, CF 3 , C 1 -C 20 -alkyl, C 6 -C 18 -aryl, C 7 -C 19 -alkaryl, and —SiR F R G R H , wherein C 6 -C 18 -aryl or C 7 -C 19 -alkaryl can at each occurrence be optionally substituted by a residue selected from the group consisting of C 1 -C 20 -alkyl, C 7 -C 19 -alkaryl, and C 6 -C 18 -aryl;

wherein at least one selected from the group consisting of R′ 1 , R′ 2 , R′ 3 , R′ 4 , R′ 5 , R′ 6 , R′ 7 , R′ 8 , R′ 9 , and R′ 10 is CN;

each of R F , R G and R H is selected from the group consisting of unsubstituted or substituted C 6 -C 18 -aryl, C 1 -C 20 -alkyl, C 7 -C 19 -alkaryl, C 1 -C 20 -heteroalkyl and C 3 -C 17 -heteroaryl;

R A , R B , R C , R D , and R E , is independently from another selected from the group consisting of hydrogen, deuterium, CN, CF 3 , C 1 -C 20 -alkyl, C 6 -C 18 -aryl, C 7 -C 19 -alkaryl, and —SiR K R M R N , wherein C 6 -C 18 -aryl or C 7 -C 19 -alkaryl can at each occurrence be optionally substituted by a residue selected from the group consisting of C 1 -C 20 -alkyl, C 7 -C 19 -alkaryl, and C 6 -C 18 -aryl;

each of R K , R M , and R N is selected from the group consisting of unsubstituted or substituted C 6 -C 18 -aryl, C 1 -C 20 -alkyl, C 7 -C 19 -alkaryl, C 1 -C 20 -heteroalkyl and C 3 -C 17 -heteroaryl;

wherein at least one selected from the group consisting of R A , R B , R C , R D and R E is —SiR K R M R N .

2. The organic compound H according to claim 1 , wherein at least one selected from the group consisting of X′ 1 and X′ 2 is N.

3. The organic compound H according to claim 1 , wherein exactly one of R A , R B , R C , R D and R E is —SiR K R M R N .

4. The organic compound H according to claim 1 , wherein R B is —SiR K R M R N and R A , R C , R D and R E are each hydrogen.

5. The organic compound H according to claim 1 , wherein the organic compound H has a structure of the following Formula (II):

wherein R′ 1 , R′ 2 , R′ 3 , R′ 4 , R′ 5 , R′ 6 , R′ 7 , R′ 8 , R′ 9 , and R′ 10 are defined as in claim 1 .

6. The organic compound H according to claim 1 , wherein no more than two of R′ 1 , R′ 2 , R′ 3 , R′ 4 , R′ 5 , R′ 6 , R′ 7 , R′ 8 , R′ 9 , and R′ 10 are CN.

7. The organic compound H according to claim 1 , wherein exactly one of R′ 1 , R′ 2 , R′ 3 , R′ 4 , R′ 5 , R′ 6 , R′ 7 , R′ 8 , R′ 9 , and R′ 10 is CN and the remaining residues selected from R′ 1 , R′ 2 , R′ 3 , R′ 4 , R′ 5 , R′ 6 , R′ 7 , R′ 8 , R′ 9 , and R′ 10 are each hydrogen.

8. The organic compound H according to claim 1 , wherein R′ 2 is CN and R′ 1 , R′ 3 , R′ 4 , R′ 5 , R′ 6 , R′ 7 , R′ 8 , R′ 9 , and R′ 10 are each hydrogen.

9. An organic electroluminescent device comprising a light-emitting layer B containing at least one organic compound H according to claim 1 as host.

10. The organic electroluminescent device according to claim 9 , wherein said organic electroluminescent device is a device selected from the group consisting of an organic light emitting diode, a light emitting electrochemical cell, and a light-emitting transistor.

11. The organic electroluminescent device according to claim 9 , wherein the light-emitting layer B comprises:

(i) 5-99% by weightof at least one host compound H according to claim 1 ;

(ii) 1-50% by weight of at least one emitter compound E; and optionally

(iii) 0-94% by weight of at least one further host compound D not according to Formula (I); and optionally

(iv) 0-10% by weight of at least one further emitter compound F not according to Formula (I); and optionally

(v) 0-94% by weight of a solvent.

12. The organic electroluminescent device according to claim 11 , wherein the at least one emitter compound E is a TADF compound E TADF .

13. The organic electroluminescent device according to claim 9 , wherein the light-emitting layer B comprises:

(i) 5-99% by weight of at least one host compound H according to claim 1 ;

(ii) 0.1-10% by weight of at least one NRCT emitter compound E NRCT ; and

(iiia) 0.9-94.9% by weight of at least one further host compound D not according to Formula (I); or

(iiib) 0.9-94.9% by weight of at least one TADF compound E TADF not according to Formula (I); and optionally

(iv) 0-94% by weight of a solvent.

14. The organic electroluminescent device according to claim 9 further comprising at least one further host compound D, wherein the organic compound H has a lowest unoccupied molecule orbital LUMO(H) having an energy E LUMO (H) and the at least one further host compound D has a lowest unoccupied molecule orbital LUMO(D) having an energy E LUMO (D), wherein E LUMO (H)<E LUMO (D).

15. The organic electroluminescent device according to claim 12 , wherein the TADF emitter compound E TADF consists of a structure according to Formula (Is):

wherein

n is at each occurrence independently from another 1 or 2;

X s is SiPh 3 , CN or CF 3 ;

Ar EWG is at each occurrence independently from another a structure according to one of Formulas IIsa to IIsm

Formula IIsm

wherein # s represents the binding site of the single bond linking Ar EWG to the substituted central phenyl ring of Formula 1s;

R t is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, C 1 -C 5 -alkyl, wherein one or more hydrogen atoms are optionally substituted by deuterium, and C 6 -C 18 -aryl, which is optionally substituted with one or more substituents R 6s ;

R s is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, N(R 5s ) 2 , OR 5s ,

SR 5s , Si(R 5s ) 3 , CF 3 , CN, F,

C 1 -C 40 -alkyl which is optionally substituted with one or more substituents R 5s and wherein one or more non-adjacent CH 2 -groups are optionally substituted by R 5s C═CR 5s , C≡C, Si(R 5s ) 2 , Ge(R 5s ) 2 , Sn(R 5s ) 2 , C═O, C═S, C═Se, C═NR 5s , P(═O)(R 5s ), SO, SO 2 , NR 5s , O, S or CONR 5s ;

C 1 -C 40 -thioalkoxy which is optionally substituted with one or more substituents RSS and wherein one or more non-adjacent CH 2 -groups are optionally substituted by R 5s C═CR 5s , C≡C, Si(R 5s ) 2 , Ge(R 5s ) 2 , Sn(R 5s ) 2 , C═O, C═S, C═Se, C═NR 5s , P(═O)(R 5s ), SO, SO 2 , NR 5s , O, S or CONR 5s ; and

C 6 -C 60 -aryl which is optionally substituted with one or more substituents R 5s ;

C 3 -C 57 -heteroaryl which is optionally substituted with one or more substituents R 5s ;

R 5s is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, N(R 6s ) 2 , OR 6s , SR 6s , Si(R 6s ) 3 , CF 3 , CN, F,

C 1 -C 40 -alkyl which is optionally substituted with one or more substituents R 6s and wherein one or more non-adjacent CH 2 -groups are optionally substituted by R 6s C═CR 6s , C≡C, Si(R 6s ) 2 , Ge(R 6s ) 2 , Sn(R 6 S) 2 , C═O, C═S, C═Se, C═NR 6s , P(═O)(R 6s ), SO, SO 2 , NR 6s , O, S or CONR 6s ,

C 6 -C 60 -aryl which is optionally substituted with one or more substituents R 6s ; and

C 3 -C 57 -heteroaryl which is optionally substituted with one or more substituents R 6s ;

R 6s is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, OPh, CF 3 , CN, F,

C 1 -C 5 -alkyl, wherein one or more hydrogen atoms are optionally, independently from each other substituted by deuterium, CN, CF 3 , or F; C 1 -C 5 -alkoxy,

wherein one or more hydrogen atoms are optionally, independently from each other substituted by deuterium, CN, CF 3 , or F;

C 1 -C 5 -thioalkoxy, wherein one or more hydrogen atoms are optionally, independently from each other substituted by deuterium, CN, CF 3 , or F;

C 6 -C 18 -aryl which is optionally substituted with one or more C 1 -C 5 -alkyl substituents;

C 3 -C 17 -heteroaryl which is optionally substituted with one or more C 1 -C 5 -alkyl substituents;

N(C 6 -C 18 -aryl) 2 ,

N(C 3 -C 17 -heteroaryl) 2 , and

N(C 3 -C 17 -heteroaryl)(C 6 -C 18 -aryl);

R d is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, N(R 5s ) 2 , OR 5s ,

SR 5s , Si(R 5s ) 3 , CF 3 , CN, F,

C 1 -C 40 -alkyl which is optionally substituted with one or more substituents R 5s and wherein one or more non-adjacent CH 2 -groups are optionally substituted by R 5s C═CR 5s , C≡C, Si(R 5s ) 2 , Ge(R 5s ) 2 , Sn(R 5s ) 2 , C═O, C═S, C═Se, C═NR 5s , P(═O)(R 5s ), SO, SO 2 , NR 5s , O, S or CONR 5s ;

C 1 -C 40 -thioalkoxy which is optionally substituted with one or more substituents R 5s and wherein one or more non-adjacent CH 2 -groups are optionally substituted by R 5s C═CR 5s , C≡C, Si(R 5s ) 2 , Ge(R 5s ) 2 , Sn(R 5s ) 2 , C═O, C═S, C═Se, C=NR 5s , P(═O)(R 5s ), SO, SO 2 , NR 5s , O, S or CONR 5s ; and

C 6 -C 60 -aryl which is optionally substituted with one or more substituents R 5s ;

C 3 -C 57 -heteroaryl which is optionally substituted with one or more substituents R 5s ;

wherein the substituents R s , or R 5s independently from each other optionally may form a mono- or polycyclic, (hetero)aliphatic, (hetero)aromatic and/or benzo-fused ring system with one or more substituents R s or R 5s and

wherein the one or more substituents R d independently from each other optionally may form a mono- or polycyclic, (hetero)aliphatic, (hetero)aromatic and/or benzo-fused ring system with one or more substituents R d .

16. The organic electroluminescent device according to claim 15 , wherein n=2 and X s is CN.

17. The organic electroluminescent device according to claim 15 , wherein R s is at each occurrence independently from another selected from the group consisting of

hydrogen, deuterium, Me, i Pr, t Bu, CN, CF 3 ,

Ph, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, i Pr, t Bu, CN, CF 3 and Ph;

pyridinyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, i Pr, t Bu, CN, CF 3 and Ph;

pyrimidinyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, i Pr, t Bu, CN, CF 3 and Ph;

carbazolyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, i Pr, t Bu, CN, CF 3 and Ph;

triazinyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, i Pr, t Bu, CN, CF 3 and Ph; and

N(Ph) 2 .

18. The organic electroluminescent device according to claim 13 , wherein the NRCT emitter compound E NRCT consists of a structure according to Formula (In):

wherein

n n is 0 or 1;

m=1−n n ;

X 1 is N or B;

X 2 is N or B;

X 3 is N or B;

W is selected from the group consisting of Si(R 3 ) 2 , C(R 3 ) 2 and BR 3 ;

each of R 1 , R 2 and R 3 is independently from each other selected from the group consisting of:

C 1 -C 5 -alkyl, which is optionally substituted with one or more substituents R 6 ;

C 6 -C60-aryl, which is optionally substituted with one or more substituents R 6 ; and

C 3 -C 57 -heteroaryl, which is optionally substituted with one or more substituents R 6 ;

each of R I , R II , R III , R IV , R V , R VI , R VII , R VIII , R IX , R X , and R XI independently from another selected from the group consisting of:

hydrogen,

deuterium,

N(R 5 ) 2 ,

OR 5 ,

Si(R 5 ) 3 ,

B(OR 5 ) 2 ,

OSO 2 R 5 ,

CF 3 ,

CN,

halogen,

C 1 -C 40 -alkyl,

which is optionally substituted with one or more substituents R 5 and

wherein one or more non-adjacent CH 2 -groups are each optionally substituted by R 5 C═CR 5 , C≡C, Si(R 5 ) 2 , Ge(R 5 ) 2 , Sn(R 5 ) 2 , C═O, C═S, C═Se, C═NR 5 , P(═O)(R 5 ), SO, SO 2 , NR 5 , O, S or CONR 5 ,

C 1 -C 40 -alkoxy,

which is optionally substituted with one or more substituents R 5 and

wherein one or more non-adjacent CH 2 -groups are each optionally substituted by R 5 C═CR 5 , C≡C, Si(R 5 ) 2 , Ge(R 5 ) 2 , Sn(R 5 ) 2 , C═O, C═S, C═Se, C═NR 5 , P(═O)(R 5 ), SO, SO 2 , NR 5 , O, S or CONR 5 ;

C 1 -C 40 -thioalkoxy,

which is optionally substituted with one or more substituents R 5 and

wherein one or more non-adjacent CH 2 -groups are each optionally substituted by R 5 C═CR 5 , C≡C, Si(R 5 ) 2 , Ge(R 5 ) 2 , Sn(R 5 ) 2 , C═O, C═S, C═Se, C═NR 5 , P(═O)(R 5 ), SO, SO 2 , NR 5 , O, S or CONR 5 ;

C 2 -C 40 -alkenyl,

which is optionally substituted with one or more substituents R 5 and

wherein one or more non-adjacent CH 2 -groups are each optionally substituted by R 5 C═CR 5 , C≡C, Si(R 5 ) 2 , Ge(R 5 ) 2 , Sn(R 5 ) 2 , C═O, C═S, C═Se, C═NR 5 , P(═O)(R 5 ), SO, SO 2 , NR 5 , O, S or CONR 5 ;

C 2 -C 40 -alkynyl,

which is optionally substituted with one or more substituents R 5 and

wherein one or more non-adjacent CH 2 -groups are each optionally substituted by R 5 C═CR 5 , C≡C, Si(R 5 ) 2 , Ge(R 5 ) 2 , Sn(R 5 ) 2 , C═O, C═S, C═Se, C═NR 5 , P(═O)(R 5 ), SO, SO 2 , NR 5 , O, S or CONR 5 ;

C 6 -C 60 -aryl,

which is optionally substituted with one or more substituents R 5 ; and C 3 -C 57 -heteroaryl,

which is optionally substituted with one or more substituents R 5 ;

R 5 is at each occurrence independently from another selected from the group consisting of: hydrogen, deuterium, OPh, CF 3 , CN, F,

wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF 3 , or F;

C 1 -C 5 -alkoxy,

wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF 3 , or F;

C 1 -C 5 -thioalkoxy,

wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF 3 , or F;

C 2 -C 5 -alkenyl,

wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF 3 , or F;

C 2 -C 5 -alkynyl,

wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF 3 , or F;

C 6 -C 18 -aryl,

which is optionally substituted with one or more C 1 -C 5 -alkyl substituents;

C 3 -C 17 -heteroaryl,

which is optionally substituted with one or more C 1 -C 5 -alkyl substituents;

N(C 6 -C 18 -aryl) 2 ,

N(C 3 -C 17 -heteroaryl) 2 ; and

N(C 3 -C 17 -heteroaryl)(C 6 -C 18 -aryl);

R 6 is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, OPh, CF 3 , CN, F,

C 1 -C 5 -alkyl,

wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF 3 , or F;

C 1 -C 5 -alkoxy,

wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF 3 , or F;

C 1 -C 5 -thioalkoxy,

wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF 3 , or F;

C 2 -C 5 -alkenyl,

wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF 3 , or F;

C 2 -C 5 -alkynyl,

wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF 3 , or F;

C 6 -C 18 -aryl,

which is optionally substituted with one or more C 1 -C 5 -alkyl substituents;

C 3 -C 17 -heteroaryl,

which is optionally substituted with one or more C 1 -C 5 -alkyl substituents;

N(C 6 -C 18 -aryl) 2 ,

N(C 3 -C 17 -heteroaryl) 2 ; and

N(C 3 -C 17 -heteroaryl)(C 6 -C 18 -aryl);

wherein two or more of the substituents selected from the group consisting of R I , R II , R III , R IV , R V , R VI , R VII , R VIII , R IX , R X , and R XI that are positioned adjacent to another may each optionally form a mono- or polycyclic, aliphatic, aromatic and/or benzo-fused ring system with another; and

wherein at least one selected from the group consisting of X 1 , X 2 and X 3 is B and at least one selected from the group consisting of X 1 , X 2 and X 3 is N.

19. The organic electroluminescent device according to claim 18 , wherein X 1 , and X 3 each are N and X 2 is B and n n =0.

20. The organic compound H according to claim 1 , wherein both of X′ 1 and X′ 2 are each N.

21. The organic compound H according to claim 1 , wherein exactly one of R A , R B , R C , R D and R E is —SiR K R M R N and the remaining residues selected from R A , R B , R C , R D and R E are each hydrogen.