Zusammenfassung
Neutral complexes [MII(C5Me5)(Q2-)(NO+)] with M=Ru or Os and the catecholates Q2- with 3,5-di-tert-Bu (dtbc) or 3,4,5,6-tetrachloro substituents (tcc) were identified with the oxidation and charge states indicated. Reversible electron transfer was analyzed spectroelectrochem. (EPR, UV-vis-NIR, IR), supported by DFT calculations Reversible reduction was observed for [Ru(C5Me5)(tcc)(NO)] to occur on the nitrosyl ligand to yield the NO radical complex [RuII(C5Me5)(tcc2-)(NO.)]-, whereas the stepwise oxidation yielded o-semiquinone cations, [MII(C5Me5)(Q.-)(NO+)]+, and dications. The metals remained in the stable low-spin d6 states, RuII and OsII, resp. Redox potentials were found to depend strongly on the donor or acceptor substitution pattern at Qn.
Nutzer