Utilizing a hexadentate ligand platform, a trinuclear manganese complex of the type ( HL)Mn 3(thf) 3 was synthesized and characterized ([ HL] 6- = [MeC(CH 2N(C 6H 4-o-NH)) 3] 6-). The pale-orange, formally divalent trimanganese complex rapidly reacts with O-atom transfer reagents to afford the μ 6-oxo complex ( HL) 2Mn 6(μ 6-O)(NCMe) 4, where two trinuclear subunits bind the central O-atom and the ( HL) ligands cooperatively bind both trinuclear subunits. The trimanganese complex ( HL)Mn 3(thf) 3 rapidly consumes inorganic azide ([N 3]NBu 4) to afford a dianionic hexanuclear nitride complex [( HL) 2Mn 6(μ 6-N)](NBu 4) 2, which subsequently can be oxidized with elemental iodine to ( HL) 2Mn 6(μ 6-N)(NCMe) 4. EPR and alkylation of the interstitial light atom substituent were used to distinguish the nitride from the oxo complex. The oxo and oxidized nitride complexes give rise to well-defined Mn(II) and Mn(III) sites, determined by bond valence summation, while the dianionic nitride shows a more symmetric complex, giving rise to indistinguishable ion oxidation states based on crystal structure bond metrics.
ASJC Scopus subject areas
- Colloid and Surface Chemistry