Synthesis, structure, and solution equilibria of diamagnetic and paramagnetic azooximates of bivalent platinum. Geometrical change associated with ligand-based electroprotic reactions

A one-electron-one-proton electroprotic transformation enables the conversion of trans-Pt(pbo)2 (Hpbo = PhN double bond Nc(Ph) double bond NOH), prepared from a reaction between Hpbo and K2PtCl4, into a cis-dimer complex. Both trans and cis complexes exhibit diamagnetism in the solid state, and in solution the dimer undergoes dissociation. X-ray and spectroscopic studies help characterize these complexes. In the dimer, dz2-dz2 and azo-azo interactions exhibit significant contribution to binding, while the unpaired electron in the monomer is significantly azo-pi in nature.