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).