The neutral complexes [(N^N)PtMes2], N^N = bis(1‐methyl‐2‐imidazolyl)ketone (bik) or N,N'‐disubstituted 1,2‐bis‐iminoacenaphthenes (R‐BIAN), Mes = mesityl, were obtained and characterized as PtII species with planar N2PtC2 configuration and charge transfer transitions in the visible. Reversible one‐electron reduction produces radical anion complexes with the spin predominantly localized in the N^N ligand, according to EPR, UV/Vis‐IR spectroelectrochemistry, DFT and TD‐DFT studies. Reversible one‐electron oxidation was also possible, attributed to the steric and electronic influence from the mesityl ligands. The EPR silent cation [(bik)PtMes2]+ was characterized by UV/Vis‐NIR spectroscopy and TD‐DFT calculations as a system with spin density contributions from Pt (31 %) and two mesityl groups (69 %).