The first mu(6)-peroxide transition-metal complex: [Ni(8)(L)(12)(O2](2+)

Caged peroxide: An octanuclear nickel complex, which exhibits peroxide in an unprecedented 6-(1)3 coordination mode, was prepared (see structure: only the Ni8 unit with the central peroxo ligand and the bridging oxygen atoms is shown; green Ni, red O). This mode of binding finally completes the series of symmetrical n-(1)n/2 peroxide binding modes in complexes.