Spiro-cyclometalated iridium emitters for OLED applications

An iridium containing emitter, comprising:

• a coordination complex with an octahedral coordination geometry comprising a central iridium atom and a tetradentate cyclometalated ligands including at least one spiro linkage and a bidentate ligand, the iridium containing emitter comprising a general structure of
• wherein each R1, R2 in (R1)4 and (R2)3, respectively, independently represents hydrogen, optionally substituted C1-C4 alkyl, optionally substituted aryl, heteroaryl, halogen, acyl, alkoxy, acyloxy, amino, nitro, acylamino, aralkyl, cyano, carboxyl, thiol, styryl, aminocarbonyl, carbamoyl, aryloxycarbonyl, phenoxycarbonyl, or an alkoxycarbonyl group;
• each pair of adjacent R groups in (R1)4, and (R2)3 can independently form 5-8 member ring(s);
• D represents a C—C bond, O, S, NR3a, C(R3b)(R3b), wherein each of R3a and R3b independently represents hydrogen, optionally substituted phenyl, heteroaryl or optionally substituted C1-C4 alkyl;
• each pair of adjacent R groups in R3a and R3b can independently form 5-8 member ring(s);
• wherein each A1-A11, B1 and B2 independently represents N, O, S, C, NR4a, C(R4b)(R4b), wherein each of R4a and R4b independently represents hydrogen or optionally substituted C1-C4 alkyl, optionally substituted aryl, heteroaryl, halogen, acyl, alkoxy, acyloxy, amino, nitro, acylamino, aralkyl, cyano, carboxyl, thiol, styryl, aminocarbonyl, carbamoyl, aryloxycarbonyl, phenoxycarbonyl, or an alkoxycarbonyl group;
• each pair of adjacent R groups in R4a and R4b can independently form 5-8 member ring(s);
• wherein B1 or B2 can be absent and in this case the carbocyclic or heterocyclic group is a 5-member ring;
• wherein X1—X4 independently represents C or N and at least one of X1—X4 is C;
• and
• L{circumflex over ( )}L is a bidentate ligand;
• wherein each L in L{circumflex over ( )}L represents a phenyl, naphthalenyl, dibenzofuranyl, pyridinyl, pyrimidyl, pyrazolyl, quinazolinyl, quinolinyl, isoquinolinyl, imidazolyl, triazolyl, thiophenyl, benzothiazolyl, or benzimidazolyl moiety, which are optionally substituted with halogen, C1-C4 alkyl or C1-C4 haloalkyl;
• or L{circumflex over ( )}L represents an acetylacetonyl, 2,2,6,6-tetramethylheptane-3,5-dionyl, phenyl-substituted β-ketoiminate, phenyl-substituted β-diketiminate, picolinate or tetraphenyldithioimidodiphosphinate moiety.