ESR study of paramagnetic centres in irradiated platinum complexes

Platinum dichloride complexes with diolefins and phosphines were γ-irradiated at 77K and studied by ESR spectroscopy. Several paramagnetic species were simultaneously produced by electron capture, electron loss and bond homolysis in the pure compounds. An high selectivity in the generation of the reduced species was reached by the irradiation at 77K of the metal complexes in methyltetrahydrofuran solutions. The ESR spectra analysis of the paramagnetic Pt(I) species suggested a SOMO of σ-antibonding character for diolefins complexes and 7π-out-of-plane character for phosphine complexes.