Gram Scale Synthesis of Benzophenanthroline and Its Blue Phosphorescent Platinum Complex

The
design, synthesis, and characterization of 12-phenyl­benzo­[f]­[1,7]­phenanthroline, Bzp, is reported. Its
use as a fluorine-free ligand for sky blue phosphorescence is demonstrated
in a cyclometalated platinum complex, BzpPtDpm. BzpPtDpm phosphoresces
at the same wavelength as its analogous 4,6-difluoro­phenyl­pyridine
complex at both room temperature (466 nm) and 77 K (458 nm). Finally,
production of a conformationally restricted derivative of BzpPtDpm
with greatly increased quantum yield (46%) validates the versatility
of the synthetic route.