Patent ID: 7846763

Claim:
An organic light-emitting diode comprising at least one uncharged transition metal complex of the formula (I) comprising at least one carbene ligand wherein the symbols have the following meanings: M 1 is Ir in any oxidation state possible; carbene is a carbene ligand selected from the group consisting of the following formulae wherein Z, Z′ are identical or different and are each CH or N; R 12 ,R 12′ are identical or different and are each an alkyl, aryl, heteroaryl or alkenyl radical, or 2 radicals R 12 or R 12′ together form a fused-on ring which may contain at least one heteroatom, or R 12 or R 12′ is a radical which acts as a donor or acceptor; t and t′ are identical or different and are each from 0 to 3, and when t or t′>1 the radicals R 12 or R 12′ can be identical or different; R 4 , R 5 , R 6 , and R 7 are each hydrogen, alkyl, aryl, heteroaryl or alkenyl or a radical which acts as a donor or acceptor; R 10 is alkyl, aryl, heteroaryl or alkenyl or 2 radicals R 10 together form a fused-on ring which may contain at least one heteroatom, or R 10 is a radical which acts as a donor or acceptor; and v is from 0 to 4 and when v is 0 the four carbon atoms of the aryl radical in the formula c which may be substituted by R 10 bear hydrogen atoms; L is a monoanionic or dianionic ligand, which may be monodentate or bidentate; K is an uncharged monodentate or bidentate ligand selected from the group consisting of phosphines; phosphonates and derivatives thereof, arsenates and derivatives thereof; phosphites; CO; pyridines; nitriles and conjugated dienes which form a π complex with M 1 ; n is the number of carbene ligands, wherein n is at least 1 and when n>1 the carbene ligands in the complex of the formula I can be identical or different; m is the number of ligands L, wherein m can be 0 or ≧1 and when m>1 the ligands L can be identical or different; o is the number of ligands K, wherein o can be 0 or ≧1 and when o>1 the ligands K can be identical or different; wherein the sum n+m+o is dependent on the oxidation state and coordination number of the metal atom and on the denticity of the ligands carbene, L and K and also on the charge on the ligands carbene and L, with the proviso that n is at least 1.