Organic electroluminescent materials and devices

A compound, or a neutral molecular form thereof, or a monovalent or polyvalent form thereof, or a monomeric or polymeric form thereof, or a macromolecular or supramolecular form thereof;

• wherein the compound has a Formula Ir(LA)x(LB)y(LC)z, wherein:
• each of x and y is independently 1 or 2, z is 0 or 1, and x+y+z=3;
• ligand LA comprises a structure of Formula I,
• ligand LB comprises a structure of Formula II,
• ligand LC is a bidentate ligand;
• each of X2 to X17 is independently C or N;
• each of RA, RB, RC, RD, and RE independently represents mono to the maximum allowable substitutions, or no substitutions;
• each R2, RA, RB, RC, RD, RE are each independently hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, germyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, selenyl, and combinations thereof;
• R1 is a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, germyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, selenyl, and combinations thereof;
• at least one of R1, R2, RA, RB, RC, RD, and RE comprises an electron-withdrawing group, moiety E;
• any two substituents may be joined or fused to form a ring;
• with the proviso that if R1 is methyl, ethyl, phenyl, or isopropyl, LB does not comprise moiety E, ligand LA comprises moiety E, and moiety E is CN or F, then at least one the following conditions is true:
• (1) a pair of RB are joined or fused to form a 5-membered ring or a polycyclic fused ring system;
• (2) an RB and an RC are joined or fused to form a ring;
• (3) a pair of RA are joined or fused to form a ring;
• (4) a pair of RC are joined or fused to form a ring;
• (5) a pair of RD are joined or fused to form a ring;
• and
• (6) at least one R1, R2, RA, RB, RC, RD, and RE comprises deuterium, silyl, boryl, selenyl, germyl, phosphorous containing group, benzo[d]benzo[4,5]imidazo[1,2-a]imidazole, tetraphenylene, alkyl with 5 or more carbon atoms, a bicyclic ring, or polycyclic fused ring system comprising aromatic ring fused to a non-aromatic ring;
• and with the proviso that if one of R1, RA, RB, or RC is deuterium, then LB is not
• wherein the compound is not

An organic light emitting device (OLED) comprising:

• an anode;
• a cathode;
• and
• an emissive layer (EML), disposed between the anode and the cathode;
• wherein the EML comprises a compound S1 and a compound A1;
• wherein the compound S1 is an organometallic sensitizer that transfers energy to the compound A1;
• wherein Si comprises a structure of Formula Ir(LA*)x*(LB*)y*(LC*)z*:
• wherein x* is 1 or 2, y* is 1 or 2;
• z* is 0 or 1;
• and x*+y*+z*=3,
• wherein LA* comprises a structure of Formula III,
• where:
• moiety A is a monocyclic or a fused polycyclic ring system, each ring of the monocyclic or the fused polycyclic ring system is a 5-membered or 6-membered carbocyclic or heterocyclic ring;
• K1′ is selected from the group consisting of a single bond, O, S, NRe, PRe, BRe, CReRf, and SiReRf, each of X1 to X5, and Z1 is independently C or N;
• each of RAA and RBB independently represents mono to the maximum allowable substitutions, or no substitutions;
• RAA and RBB are each independently hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, germyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, selenyl, and combinations thereof;
• any two substituents can be joined or fused to form a ring;
• each of LA*, LB*, and LC* is independently a bidentate ligand;
• at least one of RAA and RBB comprises an electron-withdrawing group, moiety E;
• and
• the compound A1 is capable of functioning as a fluorescent emitter at room temperature.