Inverting Pt–I Bond Polarization to Generate Iodonium Character

Tuning metal–ligand cooperativity to effect monodentate ligand charge has not been widely studied outside of metal hydrides. Here, we explore how metal coordination sphere can be manipulated to invert the polarization of Pt–I bonds and generate electrophilic behavior at I. Coordinative unsaturation trans to I is key to inverting the natural Pt–I bond polarization and is utilized to enable the electrophilic behavior of I in cationic platinum iodide complexes. The synthesis and characterization of the iodination products of reacting biscyclometalated arylpyridines (Pt(phpy)₂) with I₂ and R₃PI⁺ are reported. Abstracting iodide from Pt(phpy)₂I₂ yields a putative 5-coordinate Pt intermediate capable of transferring iodonium to a bulky phosphine. These experimental results are further assessed through charge calculations and energy decomposition analysis (EDA).