Organic electroluminescent materials and devices

1. A heteroleptic iridium compound having the formula Ir(L 1 ) n (L 2 ) 3−n :

wherein the ligand L 1 is a first ligand having Formula I,

wherein the ligand L 2 is a second ligand selected from the group consisting of

wherein L 1 is different from L 2 ;

wherein R 1 is a partially or fully deuterated group selected from the group consisting of alkyl and cycloalkyl;

wherein R 2 represents mono, di, or tri substitutions;

wherein R 3 , R 4 and R 5 each represent mono, di, tri, tetra substitutions or no substitution;

wherein each R 2 is hydrogen or alkyl;

wherein at least one R 2 is non-deuterated alkyl;

wherein each R 3 is selected from the group consisting of hydrogen, deuterium, alkyl, and combinations thereof;

wherein R 4 and R 5 are each independently selected from the group consisting of hydrogen, deuterium, alkyl, aryl, heteroaryl, and combinations thereof;

wherein R A , and R C each represent mono, di, tri, tetra substitutions or no substitution;

wherein R B represents no substitution up to maximum possible substitutions; and

wherein R A , R B , and R C are independently selected from the group consisting of hydrogen, deuterium, methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 2-methylpropyl, pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, and combinations thereof, and

wherein n is 1 or 2.

2. The compound of claim 1 , wherein R 1 is a fully deuterated group selected from the group consisting of alkyl and cycloalkyl.

3. The compound of claim 1 , wherein R 1 is a fully deuterated group selected from the group consisting of methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 2-methylpropyl, pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, cyclopentyl, and cyclohexyl.

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

5. The compound of claim 1 , wherein L 2 is selected from the group consisting of:

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

7. A first device comprising a first organic light emitting, further comprising:

an anode;

a cathode; and

an organic layer, disposed between the anode and the cathode, comprising a compound having the formula Ir(L 1 ) n (L 2 ) 3−n :

wherein the ligand L 1 is a first ligand having Formula I,

wherein the ligand L 2 is a second ligand selected from the group consisting of

wherein L 1 is different from L 2 ;

wherein R 1 is a partially or fully deuterated group selected from the group consisting of alkyl and cycloalkyl;

wherein R 2 represents mono, di, or tri substitutions;

wherein R 3 , R 4 and R 5 each represent mono, di, tri, tetra substitutions or no substitution;

wherein each R 2 is hydrogen or alkyl;

wherein at least one R 2 is non-deuterated alkyl;

wherein each R 3 is selected from the group consisting of hydrogen, deuterium, alkyl, and combinations thereof;

wherein R 4 and R 5 are each independently selected from the group consisting of hydrogen, deuterium, alkyl, aryl, heteroaryl, and combinations thereof;

wherein R A , and R C each represent mono, di, tri, tetra substitutions or no substitution;

wherein R B represents no substitution up to maximum possible substitutions; and

wherein R A , R B , and R C are independently selected from the group consisting of hydrogen, deuterium, methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 2-methylpropyl, pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, and combinations thereof, and

wherein n is 1 or 2.

8. The first device of claim 7 , wherein the first device is a consumer product selected from the group consisting of flat panel displays, computer monitors, medical monitors, televisions, billboards, lights for interior or exterior illumination and/or signaling, heads up displays, fully transparent displays, flexible displays, laser printers, telephones, cell phones, personal digital assistants (PDAs), laptop computers, digital cameras, camcorders, viewfinders, micro-displays, vehicles, a wall, theater or stadium screens, and signs.

9. The first device of claim 7 , wherein the organic layer is an emissive layer and the compound is an emissive dopant.

10. The first device of claim 7 , wherein the organic layer is an emissive layer and the compound is a non-emissive dopant.

11. The first device of claim 7 , wherein the organic layer further comprises a host.

12. The first device of claim 11 , 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≡C—C n H 2n+1 , Ar 1 , Ar 1 —Ar 2 , and C n H 2n —Ar 1 ;

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.

13. The first device of claim 11 , wherein the host comprises a compound selected from the group consisting of: carbazole, dibenzothiophene, dibenzofuran, dibenzoselenophene, azacarbazole, aza-dibenzothiophene, aza-dibenzofuran, and aza-dibenzoselenophene.

14. The first device of claim 11 , wherein the host is selected from the group consisting of:

and combinations thereof.

15. The first device of claim 11 , wherein the host comprises a metal complex.

16. A formulation comprising a compound according to claim 1 .