Long-lived photoluminescence from an eight-coordinate zirconium(IV) complex with four 2-(2′-pyridyl)pyrrolide ligands

The photoluminescent eight-coordinate zirconium complex Zr(^HPMP^H)₄ supported by four monoanionic 2-(2′-pyridine)pyrrolide ligands was synthesized. This molecule shows dual emission via fluorescence and phosphorescence with an overall quantum efficiency of 4% at room temperature in solution. The phosphorescence lifetime is dependent on concentration, indicating excimer formation at higher concentrations, and reaches almost 800 μs at high dilution.