Synthesis, Purification, and Electrochemical Analysis of Platinum Chloride Complexes with Varying Steric and Electronic Properties

A series of platinum chloride complexes were synthesized with varying steric and electronic properties. New synthetic and purification methods were developed to improve percent yield and shorten reaction times. After successful purification, the d8, diamagnetic platinum complexes were characterized using a variety of methods including, 1H, 13C, and 19F NMR spectroscopy and single crystal X-ray crystallography. Across all electronic and steric variations in ketoimine structure, all complexes were found to be four-coordinate, square planar platinum (II) chloride complexes. Further analysis of the electronic properties of both the ketoimines and platinum complexes were studied with cyclic voltammetry. In both the ligands and the platinum complexes differences were observed in redox potentials between electron-donating and electron-withdrawing groups in ketoimine substituent groups. Absorbance spectroscopy and time-dependent density functional theory (TD-DFT) calculations of the platinum complexes were also utilized to demonstrate how variations in ketoimine substituent groups affected molecular orbital energies and observed electronic transitions.