Patent ID: 8247574

Claim:
An organic light-emitting diode comprising a least one transition metal-carbene complex selected from transition metal-carbene complexes of the general formulae I and II. in which the symbols are each defined as follows: M 1 is Pt(II), Pd(II); L is a monodentate monoanionic ligand; R 1 , R 1 are each independently hydrogen, alkyl, cycloalkyl, aryl, heteroaryl, aralkyl; R 2 , R 3 , R 2′ , R 3′ are each independently hydrogen, alkyl, aryl; X, X′ are each independently alkylene, W − is a monoanionic counterion, wherein the transition metal-carbene complexes of the formulae (I) and (II) do not have any cyclometallation of the carbene ligands via a further carbon atom or heteroatom.