Fluoride Complexes of Cyclometalated Iridium(III)

Abstract

Many electroluminescent devices rely on cyclometalated iridium­(III). Their advancement depends on access to reactive starting materials because of the inertness of Ir­(III). Notably, fluoride complexes of bis­(cyclometalated) Ir­(III) are scarce. Syntheses of bridged and terminal fluorides are reported here. New compounds are luminescent and thermally reactive; they are characterized by ground-state and optical methods. Crystal structures were determined for one bridging and one terminal fluoride complex. The terminal fluoride shows intramolecular hydrogen bonding to an adjacent 3,5-dimethylpyrazole ligand; a lesser interaction may occur between F and a nearby aromatic C–H bond. Terminal fluoride complexes react with carbon-, silicon-, and sulfur-based electrophiles. The new complexes phosphoresce with microsecond lifetimes at 77 and 298 K. Density-functional theory calculations indicate triplet states with little contribution from fluoride. The compounds herein are versatile phosphors having the ground-state reactivity of late transition metal fluorides