Organometallic compounds for use in electroluminescent devices

An organic light emitting device, comprising:

• (a) an anode;
• (b) a cathode;
• (c) an organic layer disposed between the anode and the cathode, wherein the organic layer comprises a compound comprising a carbene ligand having the structure:
• wherein R1 is independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group;
• R2, R3, R8, R10, R11 and R12 are independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, CN, CF3, CO2R′, C(O)R′, C(O)NR′2, NR′2, NO2, OR′, SR′, SO2, SOR′, SO3R′, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group;
• and additionally or alternatively, one or more of R1 and R2, and R3, and two R8 groups, two R11 groups, and two R12 groups on the same ring together form independently a 5 or 6-member cyclic group, wherein said cyclic group is cycloalkyl, cycloheteroalkyl, aryl or heteroaryl;
• and wherein said cyclic group is optionally substituted by one or more substituents J;
• each substituent J is independently selected from the group consisting of R′, CN, CF3, C(O)OR′, C(O)R′, C(O)NR′2,. NR2, NO2, OR′, SR′, SO2, SOR′, or SO3R′, and additionally, or alternatively, two J groups on adjacent ring atoms form a fused 5- or 6-membered aromatic group;
• each R′ is independently selected from halo, H, alkyl, alkenyl, alkynyl, heteroalkyl, aralkyl, aryl and heteroaryl;
• wherein the ligand is coordinated to a metal;
• and d is 0, 1, 2, 3, or 4.

A compound selected from the group consisting of:

• wherein
• R1 is independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group;
• R2, R3, R8, R10, R11, and R12 are independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, CN, CF3, CO2R′, C(O)R′C(O)NR′2, NR′2, NO2, OR′, SR′, SO2, SOR′, SO3R′, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group;
• and additionally or alternatively, one or more of R1 and R2, and R2 and R3, and two R8 groups, two R11 groups, and two R12 groups on the same ring together form independently a 5 or 6-member cyclic group, wherein said cyclic group is cycloalkyl, cycloheteroalkyl, aryl or heteroaryl;
• and
• wherein said cyclic group is optionally substituted by one or more substituents J;
• each substituent J is independently selected from the group consisting of R′, CN, CF3, C(O)OR′, C(O)R′, C(O)NR′, NR′2, NO2, OR′, SR′, SO2, SOR′, or SO3R′, and additionally, or alternatively, two J groups on adjacent ring atoms form a fused 5 -or 6-membered aromatic group;
• each R′ is independently selected from halo, H, alkyl, alkenyl, alkynyl, heteroalkyl, aralkyl, aryl and heteroaryl;
• (X-Y) is selected from a photoactive ligand or an ancillary ligand,
• d is 0, 1, 2, 3, or 4;
• m is a value from 1 to the maximum number of ligands that may be attached to metal M;
• m+n is the maximum number of ligands that may be attached to metal M.