Abstract: A cationic iridium cyclometalated complex (3F−piq)₂Ir(dtb-bpy)(PF₆)( Ir1 ) with 1-(3-fluorophenyl) isoquinoline (3F−piq) as a cyclometalated ligand, 4,4′-di-tert-butyl-2,2′-bipyridine (dtb-bpy) as a neutral ligand and hexafluorophosphate as an anion has been synthesized successfully. X-ray crystallographic analysis reveals that the iridium center adopts a distorted octahedral coordination geometry. Upon excitation at 327 nm, the complex Ir1 exhibit strong red phosphorescence (λ_em=590 nm) with quantum efficiencies of 55% in oxygen-free dichloromethane solution at room temperature. Electrochemical study shows a quasireversible oxidation with potentials at 0.80−1.50 V (vs. Ag⁺/Ag), which is attributed to the redox process of Ir³⁺/Ir⁴⁺. Theoretical calculation shows that the highest occupied molecular orbital (HOMO) mostly distribute over the d orbitals of the iridium atom and the cyclometalated ligand, while the lowest unoccupied molecular orbital (LUMO) is mainly localized on the neutral ligand.