Blue phosphorescent platinum(ii) tetracarbene complexes with bis(triazoline-5-ylidene) ligands

Platinum(ii) tetracarbene complexes with chelating bis(imidazoline-2-ylidene) ligands have recently shown to be an interesting class of phosphorescent emitters, although they exhibit emission wavelengths in the near-UV region with only moderate quantum yields. By changing the bis(imidazoline-2-ylidene) ligands to bis(triazoline-5-ylidene) ligands we have successfully shifted the emission wavelengths to the visible region of the spectrum. We herein report the synthesis of new bis- and tetracarbene complexes with bis(triazoline-5-ylidene) ligands, their photophysical properties and a solid state structure of a representative member of this new class of compounds.