This invention pertains to light emitting materials comprising novel ortho-metalated transition metal complexes [C^N] 2 ML comprising two orthometalated ligands having imidazole moieties and an ancillary ligand of ²-diketonate type. It has been surprisingly found that when the metal has bound thereto both orthometalated ligands comprising imidazole moieties and an ancillary ligand of ²-diketonate type, said ligands advantageously participate in the emission process, significantly broadening emission in the visible region and enabling appreciable improvement of the white emission efficiency of complexes [C^N] 2 ML. Still objects of the invention are the use of said light emitting materials and organic light emitting device comprising said light emitting material.