Hydrogen bond controlled formation of trans-dihydroxo porphyrinato platinum(IV) complexes: Synthesis, characterization and catalytic activity in olefin epoxidation

Oxidation of PtIITMP consumes 2.0 equivalents of m-CPBA and forms a new Pt-complex that X-ray analysis formulates it as [PtVI(TMP)(OH)2](m-CB)2 based on stoichiometric titration, but other spectroscopic, electrochemical studies formulate it as [(TMP)PtIV(OH)2](m-CBA)2. Finally, theoretical studies solved the contradiction and suggested +4 oxidation state for the platinum center. These studies were employed to find the correct position of hydrogen atoms and hence, the correct structure reported as [(TMP)PtIV(OH)2](m-CBA)2 corresponding to DFT results that shows Pt-oxo and dioxo species are not stable and tend to form platinum hydroxo species.