Patent ID: 8889864

Claim:
A compound comprising a phosphorescent metal complex comprising a monoanionic, bidentate ligand selected from the group below, wherein the metal is selected from the group consisting of the non-radioactive metals with atomic numbers greater than 40, and wherein the bidentate ligand comprises a carbene donor and may be linked with other ligands to comprise a tridentate, tetradentate, pentadentate or hexadentate ligand: wherein: E 1a-q are selected from the group consisting of C and N and collectively comprise an 18 pi-electron system; wherein E 1a and E 1p are both carbon; and R 1a-i are each, independently, H, hydrocarbyl, heteroatom substituted hydrocarbyl, cyano, fluoro, OR 2a , SR 2a , NR 2a R 2b , BR 2a R 2b , or SiR 2a R 2b R 2c , where R 2a-c are each, independently, hydrocarbyl or heteroatom substituted hydrocarbyl, and where any two of R 1a-i and R 2a-c may be linked to form a saturated or unsaturated, aromatic or non-aromatic ring; provided that R 1a-i is other than H when attached to N.