Cyclometalated transition metal complex and organic electroluminescence device using the same

A cyclometalated transition metal complex represented by one of Formulae 1 through 3:

• where M is a transition metal;
• X is C, S, O, or N;
• and
• n is 1 or 2;
• is a first mono anionic bidentate chelating ligand selected from the group consisting of ligands represented by formulae below:
• where Z is S, O, or NR8, and
• R1, R2, R3, R4, R5, R6, R7, and R8 are each independently hydrogen, halogen, OH, CF3, CN, silyl, alkyl, aryl, alkoxy, aryloxy, amino, or arylene, wherein adjacent Rs may be fused together to form a five to seven membered aliphatic or aromatic ring;
• is a second mono anionic bidentate chelating ligand selected from the group consisting of ligands represented by formulae below:
• where Z is C, N, O, S, or P;
• q is an integer from 0 to 5;
• and
• R1 and R2 are each independently hydrogen, halogen, OH, CF3, CN, silyl, alkyl, aryl, alkoxy, aryloxy, amino, or arylene, wherein adjacent Rs may be fused together to form a five to seven membered aliphatic or aromatic ring;
• is a third mono anionic bidentate chelating ligand selected from the group consisting of ligands represented by formulae below:
• where Z is C, N, O, S, or P;
• q is an integer from 0 to 5;
• and
• R1 and R2 are each independently hydrogen, halogen, OH, CF3, CN, silyl, alkyl, aryl, alkoxy, aryloxy, amino, or arylene, wherein adjacent Rs may be fused together to form a five- to seven-membered aliphatic or aromatic ring;
• and
• is a di-anionic tetradentate chelating ligand selected from the group consisting of ligands represented by formulae below:
• where Z is C, N, O, S, or P;
• q is an integer from 0 to 5;
• and
• R1 and R2 are each independently hydrogen, halogen, OH, CF3, CN, silyl, alkyl, aryl, alkoxy, aryloxy, amino, or arylene, wherein adjacent Rs may be fused together to form a five to seven membered aliphatic or aromatic ring.

An organic light emitting device comprising:

• a pair of electrodes;
• and
• an emission layer interposed between the pair of electrodes, the organic layer comprising a cyclometalated transition metal complex represented by one of Formulae 1 through 3:
• where M is a transition metal;
• is a first mono anionic bidentate chelating ligand;
• is a second mono anionic bidentate chelating ligand;
• is a third mono anionic bidentate chelating ligand;
• is a di-anionic tetradentate chelating ligand;
• X is C, S, O, or N;
• CY1, CY2, CY3, and CY4 are each independently an aromatic ring or an aliphatic ring;
• and
• n is 1 or 2.