The Utilization of Para‐Substituted Triphenylphosphine Derivatives to Synthesize Highly Emissive Cyclometalated Platinum(II) Complexes

Abstract Herein, the synthesis and characterization of a series of heteroleptic cycloplatinated(II) complexes [Pt( p ‐MeC 6 H 4 )(dfppy)(L)], dfppy=2‐(2,4‐difluorophenyl)pyridinate), with different para ‐substituted triphenylphosphine ligands (L) are reported. The complexes exhibit greenish‐blue phosphorescence under UV light at room temperature in their solid states. Their emissions appear as structured bands which indicates that the emissions mainly originate from the electronic transitions in the dfppy ligand with small contribution of metal to ligand and/or ligand to ligand charge transfers. The phosphine ligands do not have a considerable impact on the shape and wavelength of the emissions. However, the electron density of the phosphine ligands affects the emission strengths significantly. To rationalize the experimental photophysical data, density functional theory (DFT) and time‐dependent DFT (TD‐DFT) calculations were employed for all the complexes.