Patent ID: 8377740

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 a metal atom selected from the group consisting of Co, Rh, Ir, Nb, Pd, Pt, Fe, Ru, Os, Cr, Mo, W, Mn, Tc, Re, Cu, Ag and Au in any oxidation state possible for the respective metal atom; 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 8 , R 9 , and R 11 are each hydrogen, alkyl, aryl, heteroaryl or alkenyl or a radical which acts as a donor or acceptor; 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.