Organic electroluminescent materials and devices

1 . A compound having a formula of M(L A ) x (L B ) y (L C ) z ; wherein M is Ir, L B and L C are each a bidentate ligand; and wherein x is 1 or 2; y is 0, 1 or 2; z is 0 or 1; x+y+z is the oxidation state of the metal M;

x+y+z=3 wherein:

if x is 1, then y is 2;

if y is 1 then z is 0; or

if z is 1 then y is 0;

wherein ligand L A has a structure selected from the group consisting of:

wherein:

each of A 1 , A 2 , A 3 , and A 4 is independently C or N;

wherein one of A 1 to A 4 is N;

N coordinates to a metal M together with a carbon atom from moiety A to form a five-membered chelate ring as indicated by the two dashed lines;

X 3 and X 4 are each independently CR 1 ;

X 5 and X 6 are each independently N or CR 2 ;

Q for each occurrence is independently BR e , NR e , PR e , O, S, Se, S═O, SO 2 , SiR e R f , and GeR e R f ;

the moiety A is a monocyclic or multicyclic ring structure containing unsaturated 5-membered and/or 6-membered carbocyclic or heterocyclic rings;

R A and R B represent zero, mono, or up to the maximum number of allowed substitutions to its associated ring;

each R 1 , R 2 , R A , R B , R e , and R f is independently a hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein the metal M can be coordinated to other ligands;

wherein the ligand LA can be linked with other ligands to form a tridentate, tetradentate, pentadentate, or hexadentate ligand; and

wherein two substituents can be joined or fused together to form a ring; and

wherein at least one pair of substituents selected from the group consisting of R A , R B , R e and R f are joined or fused to form a ring.

2 . The compound of claim 1 , wherein each R 1 , R 2 , R A , R B , R e , and R f is independently a hydrogen or a substituent selected from the group consisting of deuterium, fluorine, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, amino, silyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, sulfanyl, and combinations thereof.

3 . The compound of claim 1 , wherein L A is

4 . The compound of claim 1 , wherein Q is NR e .

5 . The compound of claim 1 , wherein A 1 and A 2 together form a moiety selected from the group consisting of furan, thiophene, oxazole, and thiazole.

6 . The compound of claim 1 , wherein the moiety A is a 6-membered aromatic ring.

7 . The compound of claim 1 , wherein the moiety A is a bicyclic ring structure containing two 6-membered aromatic rings.

8 . The compound of claim 1 , wherein Q for each occurrence is independently NR e , O, S, or Se.

9 . The compound of claim 1 , wherein the compound has a formula selected from the group consisting of Ir(L A )(L B ) 2 , Ir(L A ) 2 (L B ), and Ir(L A ) 2 (L C ).

10 . The compound of claim 1 , wherein L B and L C are selected from the group consisting of:

wherein:

each Y 1 to Y 13 are independently selected from the group consisting of C and N;

Y′ is selected from the group consisting of BR e , NR e , PR e , O, S, Se, C═O, S═O, SO 2 , CR e R f , SiR e R f , and GeR e R f ;

R e and R f can be fused or joined to form a ring;

each R a , R b , R c , and R d independently represents zero, mono, or up to the maximum number of allowed substitutions to its associated ring;

each R a , R b , R c , R d , R e and R f is independently a hygrogen or a subsituent selected from the group consisting of deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl,boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; and

wherein two adjacent substituents of R a , R b , R c , and R d can be fused or joined to form a ring or form a multidentate ligand.

11 . An organic light emitting device (OLED) comprising:

an anode;

a cathode; and

an organic layer disposed between the anode and the cathode, wherein the organic layer comprises a compound having a formula of M(L A ) x (L B ) y (L C ) z ; wherein M is Ir, L B and L C are each a bidentate ligand; and

wherein x is 1 or 2; y is 0, 1 or 2; z is 0 or 1; x+y+z is the oxidation state of metal M;

x+y+z=3 wherein:

if x is 1, then y is 2;

if y is 1 then z is 0; or

if z is 1 then y is 0;

wherein ligand L A has a structure selected from the group consisting of:

wherein:

each of A 1 , A 2 , A 3 , and A 4 is independently C or N;

wherein one of A 1 to A 4 is N;

N coordinates to a metal M together with a carbon atom from moiety A to form a five-membered chelate ring as indicated by the two dashed lines;

X 3 and X 4 are each independently CR 1 ;

X 5 and X 6 are each independently N or CR 2 ;

Q for each occurrence is independently BR e , NR e , PR e , O, S, Se, S═O, SO 2 , SiR e R f , and GeR e R f ;

the moiety A is a monocyclic or multicyclic ring structure containing unsaturated 5-membered and/or 6-membered carbocyclic or heterocyclic rings;

R A and R B represent zero, mono, or up to the maximum number of allowed substitutions to its associated ring;

each R 1 , R 2 , R A , R B , R e , and R f is independently a hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein the metal M can be coordinated to other ligands;

wherein the ligand L A can be linked with other ligands to form a tridentate, tetradentate, pentadentate, or hexadentate ligand; and

wherein two substituents can be joined or fused together to form a ring; and

wherein at least one pair of substituents selected from the group consisting of R A , R B , R e and R f are joined or fused to form a ring.

12 . The OLED of claim 11 , wherein the organic layer further comprises a host, wherein the host comprises at least one chemical moiety selected from the group consisting of triphenylene, carbazole, indolocarbazole, dibenzothiophene, dibenzofuran, dibenzoselenophene, 5,9-dioxa-13b-boranaphtho [3,2,1-de]anthracene, aza-triphenylene, aza-carbazole, aza-indolocarbazole, aza-dibenzothiophene, aza-dibenzofuran, aza-dibenzoselenophene, and aza-(5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracene).

13 . The OLED of claim 12 , wherein the host is selected from the group consisting of:

and combinations thereof.

14 . A consumer product comprising an organic light-emitting device (OLED) comprising:

an anode;

a cathode; and

an organic layer disposed between the anode and the cathode, wherein the organic layer comprises a compound having a formula of M (L A ) x (L B ) y (Lc) z; wherein M is Ir, L B and Lc are each a bidentate ligand; and

wherein x is 1 or 2; y is 0, 1 or 2; z is 0 or 1; x+y+z is the oxidation state of metal M;

x+y+z=3 wherein:

if x is 1, then y is 2;

if y is 1 then z is 0; or

if z is 1 then y is 0;

wherein ligand L A has a structure selected from the group consisting of:

wherein:

each of A 1 , A 2 , A 3 , and A 4 is independently C or N;

wherein one of A 1 to A 4 is N;

N coordinates to a metal M together with a carbon atom from moiety A to form a five-membered chelate ring as indicated by the two dashed lines;

X 3 and X 4 are each independently CR 1 ;

X 5 and X 6 are each independently N or CR 2 ;

Q for each occurrence is independently BR e , NR e , PR e , O, S, Se, S═O, SO 2 , SiR e R f , and GeR e R f ;

the moiety A is a monocyclic or multicyclic ring structure containing unsaturated 5-membered and/or 6-membered carbocyclic or heterocyclic rings;

R A and R B represent zero, mono, or up to the maximum number of allowed substitutions to its associated ring;

each R 1 , R 2 , R A , R B , R e , and R f is independently a hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein the metal M can be coordinated to other ligands;

wherein the ligand L A can be linked with other ligands to form a tridentate, tetradentate, pentadentate, or hexadentate ligand; and

wherein two substituents can be joined or fused together to form a ring; and

wherein at least one pair of substituents selected from the group consisting of R A , R B , R e and R f are joined or fused to form a ring.

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

16 . The compound of claim 1 , wherein L A is

17 . The compound of claim 1 , wherein at least one pair of R A substituents are joined or fused to form a ring.