C^C* Platinum(II) Complexes with Electron-Withdrawing Groups and Beneficial Auxiliary Ligands: Efficient Blue Phosphorescent Emission.

The combination of strong electron-withdrawing groups in cyclometalated N-heterocyclic carbene ligands (C^C*) with known beneficial auxiliary ligands in phosphorescent platinum(II) complexes leads to efficient light-to-deep-blue emission with quantum yields of up to 92%. All compounds were characterized and investigated regarding their photophysical, electrochemical, and thermal properties, and three complexes could additionally be characterized by solid-state structures. Density functional theory calculations (PBE0/6-311G* with dispersion correction) are reported.