Heteroleptic iridium complexes as dopants

1. A compound having the formula:

wherein R 1 and R 2 are optionally linked;

wherein the sum of the number of carbon atoms in R 1 and R 2 is at least 2;

wherein R 3 , R 4 , R 5 , and R 6 are optionally linked;

wherein R a and R b represent mono-, di-, tri- or tetra-substitution;

wherein X is selected from the group consisting of BR, NR, PR, O, S, Se, C═O, S═O, SO 2 , CRR′, SiRR′, and GeRR′;

wherein R a , R b , R, R′, R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein at least one of R a , R b , R, R′, R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 comprises a moiety selected from the group consisting of partially or fully deuterated alkyl and partially or fully deuterated cycloalkyl, and

wherein n is 1 or 2.

2. The compound of claim 1 , wherein n is 2.

3. The compound of claim 1 , wherein X is O.

4. The compound of claim 1 , wherein at least one of R 1 and R 2 is partially or fully deuterated alkyl or partially or fully deuterated cycloalkyl.

5. The compound of claim 1 , wherein R 1 is partially or fully deuterated alkyl.

6. The compound of claim 1 , wherein R 2 is partially or fully deuterated alkyl.

7. The compound of claim 1 , wherein R 1 or R 2 are independently selected from the group consisting of branched alkyl, cyclic alkyl, bicyclic alkyl, multicyclic alkyl, and partially or fully deuterated variants of the same.

8. The compound of claim 1 , wherein R 1 or R 2 is iso-propyl.

9. The compound of claim 1 , wherein R 1 or R 2 contain one or more deuterium atoms.

10. The compound of claim 1 , wherein R 1 and R 2 contain one or more deuterium atoms.

11. The compound of claim 1 , wherein R 3 , R 4 , R 5 and R 6 are independently selected from the group consisting of hydrogen, deuterium, alkyl, aryl, partially or fully deuterated variations thereof, and combinations thereof.

12. The compound of claim 1 , wherein at least one of R 3 , R 4 , R 5 and R 6 comprises partially or fully deuterated alkyl or partially or fully deuterated cycloalkyl.

13. The compound of claim 1 , wherein at least two of R 3 , R 4 , R 5 or R 6 independently comprise partially or fully deuterated alkyl or partially or fully deuterated cycloalkyl.

14. A first device comprising a first organic light emitting device, comprising:

an anode;

a cathode; and

an organic layer, disposed between the anode and the cathode, comprising a compound having the formula:

wherein R 1 and R 2 are optionally linked;

wherein the sum of the number of carbon atoms in R 1 and R 2 is at least 2;

wherein R 3 , R 4 , R 5 , and R 6 are optionally linked;

wherein R a and R b represent mono-, di-, tri- or tetra-substitution;

wherein X is selected from the group consisting of BR, NR, PR, O, S, Se, C═O, S═O, SO 2 , CRR′, SiRR′, and GeRR′;

wherein R a , R b , R, R′, R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein at least one of R a , R b , R, R′, R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 comprises a moiety selected from the group consisting of partially or fully deuterated alkyl and partially or fully deuterated cycloalkyl; and

wherein n is 1 or 2.

15. The first device of claim 14 , wherein the organic layer is an emissive layer and the compound is an emissive dopant or a non-emissive dopant.

16. The first device of claim 14 , wherein the organic layer further comprises a host.

17. The first device of claim 16 , wherein the host comprises a triphenylene containing benzo-fused thiophene or benzo-fused furan;

wherein any substituent in the host is an unfused substituent independently selected from the group consisting of C n H 2n+1 , OC n H 2n+1 , OAr 1 , N(C n H 2n+1 ) 2 , N(Ar 1 )(Ar 2 ), CH═CH—C n H 2n+1 , C≡CHC n H 2n+1 , Ar 1 , Ar 1 —Ar 2 , C n H 2n —Ar 1 , or no substitution;

wherein n is from 1 to 10; and

wherein Ar 1 and Ar 2 are independently selected from the group consisting of benzene, biphenyl, naphthalene, triphenylene, carbazole, and heteroaromatic analogs thereof.

18. The first device of claim 16 , wherein the host is selected from the group consisting of:

and combinations thereof.

19. A consumer product comprising a first organic light emitting device, comprising:

an anode;

a cathode; and

an organic layer, disposed between the anode and the cathode, comprising a compound having the formula:

wherein R 1 and R 2 are optionally linked;

wherein the sum of the number of carbon atoms in R 1 and R 2 is at least 2;

wherein R 3 , R 4 , R 5 , and R 6 are optionally linked;

wherein R a and R b represent mono-, di-, tri- or tetra-substitution;

wherein X is selected from the group consisting of BR, NR, PR, O, S, Se, C═O, S═O, SO 2 , CRR′, SiRR′, and GeRR′;

wherein R a , R b , R, R′, R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein at least one of R a , R b , R, R′, R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 comprises a moiety selected from the group consisting of partially or fully deuterated alkyl and partially or fully deuterated cycloalkyl, and

wherein n is 1 or 2.

20. The compound of claim 1 , wherein the compound is selected from the group consisting of: