Blue Light-Emitting Cyclometalated Spirofluorenexanthene Imidazolylidene Platinum(II) Complexes

Cyclometalated 2′-spirofluorenexanthene imidazolylidene (SFX-NHC) Pt(II) complexes with acetylacetonate, 1,3-bis(2,4,6-trimethylphenyl)propane-1,3-dionate, and dihydrobis(3,5-dimethylpyrazole-1-yl)borate auxiliary ligands were synthesized from readily available 2′-bromospiro[fluorene-9,9′-xanthene] (2′-Br-SFX) and characterized and investigated in terms of their photophysical properties. Photophysical properties were studied in 2 wt % PMMA films at room temperature and 2-MeTHF at 77 K. The radiative decay times vary between 4 and 48 μs. The emission peak maxima are at 420, 430, and 480 nm with photoluminescence quantum yields up to 76% and blue Commission Internationale de l’Éclairage (CIE)_xy coordinates of (0.15, 0.12).