Photophysical Properties of Cyclometalated Platinum(II) Diphosphine Compounds in the Solid State and in PMMA Films

Platinum­(II) compounds
were synthesized with both chelate cyclometalated
ligands and chelate diphosphine ligands. The cyclometalated ligands
include phenylpyridine and a benzothiophene-containing ligand. The
three new benzothiophene compounds were characterized by nuclear magnetic
resonance (NMR) spectroscopy, high-resolution mass spectrometry (HR-MS),
and photophysical measurements. In the case of one compound, L1-DPPM, the structure was determined by single crystal X-ray
diffraction. The structural coherence of the noncrystalline emissive
solid state was measured by X-ray total scattering real space pair
distribution function analysis. Quantum yield values of all of the
platinum compounds measured in the solid state and in PMMA films were
much greater than in solution.