Organic electroluminescent materials and devices

1. A compound having a formula of M(L A ) x (L B ) y (L C ) z ;

wherein L B and L C are each a bidentate ligand;

wherein x is 1, 2, or 3, y is 1 or 2, z is 0, 1, or 2;

wherein x+y+z is the oxidation state of the metal M;

wherein L A has the following formula:

wherein X 1 -X 4 are each independently selected from the group consisting of C and N;

wherein Y is selected from the group consisting of O, S, Se, NR 4 , and CR 4 R 5 ;

wherein at least one of R 3 and R 4 comprises a 5-membered or 6-membered aromatic ring;

wherein if Y is CR 4 R 5 , R 4 and R 5 are not a 5-membered or 6-membered aromatic ring;

wherein R 3 is a direct bond to a metal M or is selected from the group consisting of alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein R 4 is a direct bond to a metal M or is selected from the group consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein R A represents mono to a maximum possible number of substituents, or no substituent;

wherein R 1 , R 2 , R 5 , and R A are each independently selected from the group consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein any adjacent substitutions in R A can be joined together to form a ring;

wherein R 1 and R 2 can be joined together to form a ring;

wherein L A is coordinated to a metal M by forming a bond between M and R 3 or R 4 ;

wherein M coordinates to L A according to the following conditions:

R 3 is a direct bond to M and a second bond to M originates from an atom of Y; or

R 3 is a substituent and M bonds to the substituent R 3 ; and

wherein L A can be linked with other ligands to form a bidentate, a tridentate, a tetradentate, a pentadentate, or a hexadentate ligand.

2. The compound of claim 1 , wherein each R 1 , R 2 , R 4 , R 5 , and R A is independently selected from the group consisting of hydrogen, deuterium, fluorine, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, sulfanyl, and combinations thereof.

3. The compound of claim 1 , wherein M is selected from the group consisting of Ir, Rh, Re, Ru, Os, Pt, Au, and Cu.

4. The compound of claim 1 , wherein R 1 and R 2 are joined together to form a 6-membered aromatic ring.

5. The compound of claim 1 , wherein M is also bonded to X 1 , and X 1 is C or N.

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

wherein the dashed lines indicate coordination to the metal M;

wherein A is a 5- or 6-membered aromatic ring;

Z′ is selected from the group consisting of C and N;

wherein R A and R C′ represents mono to a maximum possible number of substituents, or no substituent;

wherein R A′ is selected from the group consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein R A and R C′ are each independently selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; and

wherein X 5 -X 12 are each independently selected from the group consisting of C and N.

7. The compound of claim 6 , wherein the first ligand L A is selected from the group consisting of:

wherein the dashed lines indicate coordination to the metal M;

wherein X 5 -X 12 are each independently selected from the group consisting of C and N; and

wherein R 6 is selected from the group consisting of alkyl, cycloalkyl, aryl, heteroaryl, and combinations thereof.

8. The compound of claim 6 , wherein the compound has a structure of one of the following formulas

wherein X 1 to X 9 , Z 7 and Z 8 are each independently selected from the group consisting of carbon and nitrogen;

wherein Y is selected from the group consisting of O, S, Se, NR′, and CR 2 R 3 ;

wherein rings A, B, and C are each independently selected from the group consisting of phenyl, pyridine, imidazole, and imidazole derived carbene;

wherein R A′ , R B , and R C each independently represents none to a maximum possible number of substituents;

wherein m1, m2, and m3 are each independently an integer of 0 or 1;

wherein when m2 is 0, each of m1 and m3 is 1;

wherein when m2 is 1, each of m1 and m3 can be 0 or 1;

wherein when m1 is 0, L 1 is not present;

wherein when m2 is 0, L 2 is not present;

wherein when m3 is 0, L 3 is not present;

wherein L 1 , L 2 , and L 3 each independently represents a direct bond or a linker selected from the group consisting of BR, NR, PR, O, S, Se, C═O, S═O, SO 2 , CRR′, SiRR′, GeRR′, alkyl, cycloalkyl, and combinations thereof;

wherein R A′ , R B , R C , R 1 , R 2 , R 3 , R′, and R″ are each independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, 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 any adjacent substitutions can be joined or fused into a ring;

wherein Q 1 and Q 2 each independently represents a direct bond or oxygen;

wherein when any of Z 7 and Z 8 is nitrogen, the corresponding Q 1 and Q 2 is a direct bond; and

wherein M is Pt or Pd.

9. The compound of claim 8 , wherein the compound is selected from the group consisting of:

wherein R A′ , R B , and R C each independently represents none to a maximum possible number of substituents;

wherein Y is selected from the group consisting of O, S, Se, NR 1 , and CR 2 R 3 ;

wherein L 1 , L 2 , and L 3 each independently represents a direct bond or a linker selected from the group consisting of BR, NR, PR, O, S, Se, C═O, S═O, SO 2 , CRR′, SiRR′, GeRR′, alkyl, cycloalkyl, and combinations thereof;

wherein R A′ , R B , R C , R 1 , R 2 , R 3 , R′ and R″ are each independently selected from the group consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; and

wherein any adjacent substitutions can be joined or fused into a ring.

10. The compound of claim 8 , wherein the compound is selected from the group consisting of Compound Cz having the formula (L Ai )Pt(L Bj );

wherein z is an integer defined by z=44(i−312)+(j−201); wherein i is an integer from 312, 314 to 331, and j is an integer from 202 to 243; and

wherein L Ai has structures based on a formula of

 selected from the group consisting of:

L A312

L A314

L A315

L A316 to L A319 having

the following structure

wherein

in L A316 , Y = O;

in L A317 , Y = S;

in L A318 , Y = NPh; and

in L A319 , Y = C(CH 3 ) 2 ;

L A320 to L A323 having

the following structure

wherein

in L A320 , Y = O;

in L A321 , Y = S;

in L A322 , Y = NPh; and

in L A323 , Y = C(CH 3 ) 2 ;

L A324 to L A327 having

the following structure

wherein

in L A324 , Y = O;

in L A325 , Y = S;

in L A326 , Y = NPh; and

in L A327 , Y = C(CH 3 ) 2 ;

L A328 to L A331 having

the following structure

wherein

in L A328 , Y = O;

in L A329 , Y = S;

in L A330 , Y = NPh; and

in L A331 , Y = C(CH 3 ) 2 ;

wherein L Bj has the following structures based on a formula of

wherein in the formula of L Ai , L 3 bonds to ring C of the formula of L Bj ,

wherein in the formula of L Bj , L 3 bonds to ring A of the formula of L Ai ;

wherein the dashed lines from nitrogen and carbon atoms indicate coordination to the metal M.

11. The compound of claim 1 , wherein the first ligand L A is selected from the group consisting of:

in L A1 , Y = O;

in L A2 , Y = S;

in L A3 , Y = N(CH 3 ); and

in L A4 , Y = C(CH 3 ) 2 ;

in L A5 , Y = O;

in L A6 , Y = S;

in L A7 , Y = N(CH 3 ); and

in L A8 , Y = C(CH 3 ) 2 ;

in L A9 , Y = O;

in L A10 , Y = S;

in L A11 , Y = N(CH 3 ); and

in L A12 , Y = C(CH 3 ) 2 ;

in L A13 , Y = O;

in L A14 , Y = S;

in L A15 , Y = N(CH 3 ); and

in L A16 , Y = C(CH 3 ) 2 ;

in L A17 , Y = O;

in L A18 , Y = S;

in L A19 , Y = N(CH 3 ); and

in L A20 , Y = C(CH 3 ) 2 ;

in L A21 , Y = O;

in L A22 , Y = S;

in L A23 , Y = N(CH 3 ); and

in L A24 , Y = C(CH 3 ) 2 ;

in L A25 , Y = O;

in L A26 , Y = S;

in L A27 , Y = N(CH 3 ); and

in L A28 , Y = C(CH 3 ) 2 ;

in L A29 , Y = O;

in L A30 , Y = S;

in L A31 , Y = N(CH 3 ); and

in L A32 , Y = C(CH 3 ) 2 ;

in L A33 , Y = O;

in L A34 , Y = S;

in L A35 , Y = N(CH 3 ); and

in L A36 , Y = C(CH 3 ) 2 ;

in L A37 , Y = O;

in L A38 , Y = S;

in L A39 , Y = N(CH 3 ); and

in L A40 , Y = C(CH 3 ) 2 ;

in L A41 , Y = O;

in L A42 , Y = S;

in L A43 , Y = N(CH 3 ); and

in L A44 , Y = C(CH 3 ) 2 ;

in L A45 , Y = O;

in L A46 , Y = S;

in L A47 , Y = N(CH 3 ); and

in L A48 , Y = C(CH 3 ) 2 ;

in L A49 , Y = O;

in L A50 , Y = S;

in L A51 , Y = N(CH 3 ); and

in L A52 , Y = C(CH 3 ) 2 ;

inL A53 , Y = O;

in L A54 , Y = S;

in L A55 , Y = N(CH 3 ); and

in L A56 , Y = C(CH 3 ) 2 ;

in L A57 , Y = O;

in L A58 , Y = S;

in L A59 , Y = N(CH 3 ); and

in L A60 , Y = C(CH 3 ) 2 ;

in L A61 , Y = O;

in L A62 , Y = S;

in L A63 , Y = N(CH 3 ); and

in L A64 , Y = C(CH 3 ) 2 ;

in L A65 , Y = O;

in L A66 , Y = S;

in L A67 , Y = C(CH 3 ) 2 ;

L A68 , Y = C(CH 3 ) 2 ;

in L A69 , Y = O;

in L A70 , Y = S;

in L A71 , Y = N(CH 3 ); and

in L A72 , Y = C(CH 3 ) 2 ;

in L A73 , Y = O;

in L A74 , Y = S;

in L A75 , Y = N(CH 3 ); and

in L A76 , Y = C(CH 3 ) 2 ;

in L A77 , Y = O;

in L A78 , Y = S;

in L A79 , Y = N(CH 3 ); and

in L A80 , Y = C(CH 3 ) 2 ;

in L A81 , Y = O;

in L A82 , Y = S;

in L A83 , Y = N(CH 3 ); and

in L A84 , Y = C(CH 3 ) 2 ;

in L A85 , Y = O;

in L A86 , Y = S;

in L A87 , Y = N(CH 3 ); and

in L A88 , Y = C(CH 3 ) 2 ;

in L A89 , Y = O;

in L A90 , Y = S;

in L A91 , Y = N(CH 3 ); and

in L A92 , Y = C(CH 3 ) 2 ;

in L A93 , Y = O;

in L A94 , Y = S;

in L A95 , Y = N(CH 3 ); and

in L A96 , Y = C(CH 3 ) 2 ;

in L A97 , Y = O;

in L A98 , Y = S;

in L A99 , Y = N(CH 3 ); and

in L A100 , Y = C(CH 3 ) 2 ;

in L A101 , Y = O;

in L A102 , Y = S;

in L A103 , Y = N(CH 3 ); and

in L A104 , Y = C(CH 3 ) 2 ;

in L A105 , Y = O;

in L A106 , Y = S;

in L A107 , Y = N(CH 3 ); and

in L A108 , Y = C(CH 3 ) 2 ;

in L A109 , Y = O;

in L A110 , Y = S;

in L A111 , Y = N(CH 3 ); and

in L A112 , Y = C(CH 3 ) 2 ;

in L A113 , Y = O;

in L A114 , Y = S;

in L A115 , Y = N(CH 3 ); and

in L A116 , Y = C(CH 3 ) 2 ;

in L A117 , wherein Y = O;

in L A118 , wherein Y = S;

in L A119 , wherein Y = N(CH 3 ); and

in L A120 , wherein Y = C(CH 3 ) 2 ;

in L A121 , Y = O;

in L A122 , Y = S;

in L A123 , Y = N(CH 3 ); and

in L A124 , Y = C(CH 3 ) 2 ;

in L A125 , Y = O;

in L A126 , Y = S;

in L A127 , Y = N(CH 3 ); and

in L A128 , Y = C(CH 3 ) 2 ;

in L A129 , Y = O;

in L A130 , Y = S;

in L A131 , Y = N(CH 3 ); and

in L A132 , Y = C(CH 3 ) 2 ;

in L A133 , Y = O;

in L A134 , Y = S;

in L A135 , Y = N(CH 3 ); and

in L A136 , Y = C(CH 3 ) 2 ;

in L A137 , Y = O;

in L A138 , Y = S;

in L A139 , Y = N(CH 3 ); and

in L A140 , Y = C(CH 3 ) 2 ;

in L A141 , Y = O;

in L A142 , Y = S;

in L A143 , Y = N(CH 3 ); and

in L A144 , Y = C(CH 3 ) 2 ;

in L A145 , Y = O;

in L A146 , Y = S;

in L A147 , Y = N(CH 3 ); and

in L A148 , Y = C(CH 3 ) 2 ;

in L A149 , Y = O;

in L A150 , Y = S;

in L A151 , Y = N(CH 3 ); and

in L A152 , Y = C(CH 3 ) 2 ;

in L A153 , Y = O;

in L A154 , Y = S;

in L A155 , Y = N(CH 3 ); and

in L A156 , Y = C(CH 3 ) 2 ;

in L A157 , Y = O;

in L A158 , Y = S;

in L A159 , Y = N(CH 3 ); and

in L A160 , Y = C(CH 3 ) 2 ;

in L A161 , Y = O;

in L A162 , Y = S;

in L A163 , Y = N(CH 3 ); and

in L A164 , Y = C(CH 3 ) 2 ;

in L A165 , Y = O;

in L A166 , Y = S;

in L A167 , Y = N(CH 3 ); and

in L A166 , Y = C(CH 3 ) 2 ;

in L A169 , Y = O;

in L A170 , Y = S;

in L A171 , Y = N(CH 3 ); and

in L A172 , Y = C(CH 3 ) 2 ;

in L A173 , Y = O;

in L A174 , Y = S;

in L A175 , Y = N(CH 3 ); and

in L A176 , Y = C(CH 3 ) 2 ;

in L A177 , Y = O;

in L A178 , Y = S;

in L A179 , Y = N(CH 3 ); and

in L A180 , Y = C(CH 3 ) 2 ;

in L A181 , Y = O;

in L A182 , Y = S;

in L A183 , Y = N(CH 3 ); and

in L A184 , Y = C(CH 3 ) 2 ;

in L A185 , Y = O;

in L A186 , Y = S;

in L A187 , Y = N(CH 3 ); and

in L A188 , Y = C(CH 3 ) 2 ;

in L A189 , Y = O;

in L A190 , Y = S;

in L A191 , Y = N(CH 3 ); and

in L A192 , Y = C(CH 3 ) 2 ;

in L A193 , Y = O;

in L A194 , Y = S;

in L A195 , Y = N(CH 3 ); and

in L A196 , Y = C(CH 3 ) 2 ;

in L A197 , Y = O;

in L A198 , Y = S;

in L A199 , Y = N(CH 3 ); and

in L A200 , Y = C(CH 3 ) 2 ;

in L A201 , Y = O;

in L A202 , Y = S;

in L A203 , Y = N(CH 3 ); and

in L A204 , Y = C(CH 3 ) 2 ;

in L A205 , Y = O;

in L A206 , Y = S;

in L A207 , Y = N(CH 3 ); and

in L A208 , Y = C(CH 3 ) 2 ;

in L A209 , Y = O;

in L A210 , Y = S;

in L A211 , Y = N(CH 3 ); and

in L A212 , Y = C(CH 3 ) 2 ;

in L A213 , Y = O;

in L A214 , Y = S;

in L A215 , Y = N(CH 3 ); and

in L A216 , Y = C(CH 3 ) 2 ;

in L A217 , Y = O;

in L A218 , Y = S;

in L A219 , Y = N(CH 3 ); and

in L A220 , Y = C(CH 3 ) 2 ;

in L A221 , Y = O;

in L A222 , Y = S;

in L A223 , Y = N(CH 3 ); and

in L A224 , Y = C(CH 3 ) 2 ;

in L A225 , Y = O;

in L A226 , Y = S;

in L A227 , Y = N(CH 3 ); and

in L A228 , Y = C(CH 3 ) 2 ;

in L A229 , Y = O;

in L A230 , Y = S;

in L A231 , Y = N(CH 3 ); and

in L A232 , Y = C(CH 3 ) 2 ;

in L A233 , Y = O;

in L A234 , Y = S;

in L A235 , Y = N(CH 3 ); and

in L A236 , Y = C(CH 3 ) 2 ;

in L A237 , Y = O;

in L A238 , Y = S;

in L A239 , Y = N(CH 3 ); and

in L A240 , Y = C(CH 3 ) 2 ;

in L A241 , Y = O;

in L A242 , Y = S;

in L A243 , Y = N(CH 3 ); and

in L A244 , Y = C(CH 3 ) 2 ;

in L A245 , Y = O;

in L A246 , Y = S;

in L A247 , Y = N(CH 3 ); and

in L A248 , Y = C(CH 3 ) 2 ;

in L A249 , Y = O;

in L A250 , Y = S;

in L A251 , Y = N(CH 3 ); and

in L A252 , Y = C(CH 3 ) 2 ;,

wherein the dashed lines indicate coordination to the metal M.

12. The compound of claim 11 , wherein the compound is selected from the group consisting of Compound By having the formula Ir(L Ai /)(L Bk ) 2 , wherein y is an integer defined by 201(i−1)+k, wherein i is an integer from 1 to 311, k is an integer from 1 to 201, and wherein L Bk has the following structures:

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

wherein the dashed lines indicate coordination to the metal M;

wherein each Y 1 to Y 13 are independently selected from the group consisting of carbon and nitrogen;

wherein Y′ is selected from the group consisting of B R e , N R e , P R e , O, S, Se, C═O, S═O, SO 2 , CR e R f , SiR e R f , and GeR e R f ;

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

wherein each R a , R b , R c , and R d may independently represent from mono substitution to the maximum possible number of substitution, or no substitution;

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

wherein any 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.

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

an anode;

a cathode; and

an organic layer, disposed between the anode and the cathode, comprising a compound having a formula of M(L A ) x (L B ) y (L C ) z ;

wherein L B and L C are each a bidentate ligand;

wherein x is 1, 2, or 3, y is 1 or 2, z is 0, 1, or 2;

wherein x+y+z is the oxidation state of the metal M;

wherein L A has the following formula:

wherein X 1 -X 4 are each independently selected from the group consisting of C and N;

wherein Y is selected from the group consisting of O, S, Se, NR 4 , and CR 4 R 5 ;

wherein at least one of R 3 and R 4 comprises a 5-membered or 6-membered aromatic ring;

wherein if Y is CR 4 R 5 , R 4 and R 5 are not a 5-membered or 6-membered aromatic ring;

wherein R 3 is a direct bond to a metal M or is selected from the group consisting of alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein R 4 is a direct bond to a metal M or is selected from the group consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein R A represents mono to a maximum possible number of substituents, or no substituent;

wherein R 1 , R 2 , R 5 , and R A are each independently selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein any adjacent substitutions in R A can be joined together to form a ring;

wherein R 1 and R 2 can be joined together to form a ring;

wherein L A is coordinated to a metal M by forming a bond between M and R 3 or R 4 ;

wherein M coordinates to L A according to the following conditions:

R 3 is a direct bond to M and a second bond to M originates from an atom of Y; or

R 3 is a substituent and M bonds to the substituent R 3 ; and

wherein L A can be linked with other ligands to form a bidentate, a tridentate, a tetradentate, a pentadentate, or a hexadentate ligand.

15. The OLED 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 OLED of claim 14 , wherein the organic layer further comprises a host, wherein host comprises at least one chemical group selected from the group consisting of triphenylene, carbazole, dibenzothiphene, dibenzofuran, dibenzoselenophene, azatriphenylene, azacarbazole, aza-dibenzothiophene, aza-dibenzofuran, and aza-dibenzoselenophene.

17. The OLED of claim 14 , wherein the organic layer further comprises a host, wherein the host is selected from the group consisting of:

and combinations thereof.

18. 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, comprising a compound having a formula of M(L A ) x (L B ) y (L C ) z ;

wherein L B and L C are each a bidentate ligand;

wherein x is 1, 2, or 3, y is 1 or 2, z is 0, 1, or 2;

wherein x+y+z is the oxidation state of the metal M;

wherein L A has the following formula:

wherein X 1 -X 4 are each independently selected from the group consisting of C and N;

wherein Y is selected from the group consisting of O, S, Se, NR 4 , and CR 4 R 5 ;

wherein at least one of R 3 and R 4 comprises a 5-membered or 6-membered aromatic ring;

wherein if Y is CR 4 R 5 , R 4 and R 5 are not a 5-membered or 6-membered aromatic ring;

wherein R 3 is a direct bond to a metal M or is selected from the group consisting of alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein R 4 is a direct bond to a metal M or is selected from the group consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein R A represents mono to a maximum possible number of substituents, or no substituent;

wherein R 1 , R 2 , R 5 , and R A are each independently selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein any adjacent substitutions in R A can be joined together to form a ring;

wherein R 1 and R 2 can be joined together to form a ring;

wherein L A is coordinated to a metal M by forming a bond between M and R 3 or R 4 ;

wherein M coordinates to L A according to the following conditions:

R 3 is a direct bond to M and a second bond to M originates from an atom of Y; or

 R 3 is a substituent and M bonds to the substituent R 3 ; and

wherein L A can be linked with other ligands to form a bidentate, a tridentate, a tetradentate, a pentadentate, or a hexadentate ligand.

19. The consumer product of claim 18 , wherein the consumer product is one of a flat panel display, a curved display, a computer monitor, a medical monitor, a television, a billboard, a light for interior or exterior illumination and/or signaling, a heads-up display, a fully or partially transparent display, a flexible display, a rollable display, a foldable display, a stretchable display, a laser printer, a telephone, a cell phone, tablet, a phablet, a personal digital assistant (PDA), a wearable device, a laptop computer, a digital camera, a camcorder, a viewfinder, a micro-display that is less than 2 inches diagonal, a 3-D display, a virtual reality or augmented reality display, a vehicle, a video walls comprising multiple displays tiled together, a theater or stadium screen, and a sign.