Organic electroluminescent materials and devices

An organic light emitting device (OLED) comprising:

• an anode;
• a cathode;
• and
• an emissive layer, disposed between the anode and cathode;
• wherein the emissive layer comprises a first compound and a second compound;
• wherein the first compound has a structure of Formula I:
• wherein:
• each of moiety A, moiety B, moiety C, and moiety D is independently a monocyclic ring or a polycyclic fused ring system, where the monocyclic ring or each ring of the polycyclic fused ring system is independently a 5-membered or 6-membered carbocyclic or heterocyclic ring;
• each of X1 to X5 is independently C or N;
• each of K1, K2, and K3 is independently selected from the group consisting of a direct bond, O, S, N(Rα), P(Rα), B(Rα), C(Rα)(Rβ), and Si(Rα)(Rβ);
• m and n are each independently 0 or 1;
• m+n=1 or 2;
• wherein the second compound has Formula II,
• wherein:
• each of Z1 to Z11 is independently C or N;
• x and y are each independently 0 or 1;
• wherein the LUMO energy of the second compound is less than or equal to −2.33 eV;
• wherein:
• each of L1, L2, L3, L4, L1, and L6 is independently selected from the group consisting of a direct bond, or a linker selected from the group consisting of BR, BRR′, NR, PR, P(O)R, O, S, Se, C═O, C═S, C═Se, C═NR′, C═CR″R′″, S═O, SO2, CR, CRR′, SiRR′, GeRR′, alkyl, cycloalkyl, aryl, heteroaryl, and combinations thereof:
• each of RA, RB, RC, RD, RE, RF, and RG independently represents mono to the maximum allowable substitution, or no substitution:
• each Rα, Rβ, R, R′, R″, R′″, RA, RB, RC, RD, RE, RF, and RG is independently a hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, boryl, arylalkyl, alkoxy, aryloxy, amino, silyl, germyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, selenyl, and combinations thereof;
• and
• any two substituents may be joined or fused to form a ring;
• with at least one of the following conditions being true:
• (1) wherein at least one RD substituent is not hydrogen:
• (2) wherein one of moiety A, B, C, or D of Formula I comprises a pyridine moiety coordinated to Pt, and the pyridine moiety having a center of gravity C1;
• wherein the closest calculated intermolecular distance at 0K between C1 and the boron atom of Formula II is greater than or equal to 3.57 Å:
• (3) wherein at least one of RE, RG, or RF of Formula II has a spherocity greater than or equal to 0.04, and the LUMO energy of Formula II is less than or equal to −2.33 eV;
• and
• (4) when moiety A is benzimidazole, each of moiety B and moiety C is phenyl, moiety D is pyridine, and X1 is N, at least one of the following two conditions is true:
• (a) a combined molecular weight of all of the at least one RD substituents that are not hydrogen is ≥57 g/mol;
• or
• (b) two RD substituents are joined together to form a ring.