Organic electroluminescent materials and devices

1. A compound having a formula is selected from the group consisting of:

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 each of A 1 , A 2 , A 3 , A 4 , A 5 , A 6 , A 7 , and A 8 independently comprise carbon or nitrogen;

wherein at most one of A 1 , A 2 , A 3 , A 4 is nitrogen;

wherein at most one of A 5 , A 6 , A 7 , A 8 is nitrogen, and the nitrogen is not bound to Pt or the adjacent pyridine ring;

wherein R 1 , R 2 , R 3 , and R 4 each independently represent no substitutions up to the maximum possible substitutions;

wherein R 1 is optionally fused, R 2 is optionally fused, R 3 is optionally fused, and R 4 is optionally fused;

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

wherein L 3 is selected from the group consisting of a single bond, BR, NR, PR, O, S, Se, C═O, S═O, SO 2 , CRR′, SiRR′, and GeRR′;

wherein R 3 and L 2 or R 4 and L 2 are optionally linked to form a ring; and

wherein R, R′, R 1 , R 2 , R 3 , and R 4 are 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, sulfonyl, sulfonyl, phosphino, and combinations thereof.

2. The compound of claim 1 , wherein the compound has a neutral charge.

3. The compound of claim 1 , wherein one of A 1 , A 2 , A 3 , and A 4 , is a nitrogen atom and/or one of A 5 , A 6 , A 7 , and A 8 is a nitrogen atom.

4. The compound of claim 1 , wherein L 3 is independently selected from the group consisting of O, S, and NR.

5. The compound of claim 4 , wherein L 3 is NR, and R is phenyl or substituted phenyl.

6. The compound of claim 4 , wherein L 3 is O.

7. The compound of claim 1 , wherein X is selected from the group consisting of O, S, and NR.

8. The compound of claim 7 , wherein X is O.

9. The compound of claim 1 , wherein the compound has the structure of Formula I-E,

10. The compound of claim 1 , wherein the compound has the structure of Formula I-F,

11. 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 a structure selected from the group consisting of:

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

wherein each of A 1 , A 2 , A 3 , A 4 , A 5 , A 6 , A 7 , and A 8 independently comprise carbon or nitrogen;

wherein at most one of A 1 , A 2 , A 3 , A 4 is nitrogen;

wherein at most one of A 5 , A 6 , A 7 , A 8 is nitrogen, and the nitrogen is not bound to Pt or the adjacent pyridine ring;

wherein R 1 , R 2 , R 3 , and R 4 each independently represent no substitutions up to the maximum possible substitutions;

wherein R 1 is optionally fused, R 2 is optionally fused, R 3 is optionally fused, and R 4 is optionally fused;

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

wherein L 3 is selected from the group consisting of a single bond, BR, NR, PR, O, S, Se, C═O, S═O, SO 2 , CRR′, SiRR′, and GeRR′;

wherein R 3 and L 2 or R 4 and L 2 are optionally linked to form a ring; and

wherein R, R′, R 1 , R 2 , R 3 , and R 4 are 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, sulfonyl, sulfonyl, phosphino, and combinations thereof.

12. The compound of claim 1 , wherein L 2 is selected from the group consisting of NR, O, and S.

13. The compound of claim 1 , wherein L 3 is NR.

14. A compound selected from the group consisting of

wherein R is independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, aryl, heteroaryl, acyl and combinations thereof.

15. The first device of claim 11 , wherein the compound is selected from the group consisting of

wherein R is independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, aryl, heteroaryl, acyl and combinations thereof.

16. The first device of claim 11 , wherein the first device is selected from the group consisting of a consumer product, an organic light-emitting device, and a lighting panel.

17. The first device of claim 11 , wherein the organic layer is an emissive layer and the compound is an emissive dopant or a non-emissive dopant.

18. The first device of claim 11 , wherein the organic layer further comprises a host comprising 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≡CC 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.

19. The first device of claim 11 , wherein the organic layer further comprises a host having the formula:

20. The first device of claim 11 , wherein the organic layer further comprises a host selected from the group consisting of

and combinations thereof.