A Thermally Stable Peroxocopper( II ) Complex with Unusual μ4‐Coordination of the Peroxo Ligand

Stable at room temperature, the peroxocopper(II) cation in 1 (HL = 4-methyl-2,6-bis(pyrrolidinomethyl)phenol) is a tetranuclear complex (the picture shows the central unit) that displays several unusual structural details, including a μ4-bridging peroxo ligand. Peroxocopper(II) complexes are, in general, unstable compounds that can often be characterized only by spectroscopic methods at low temperatures. • equals; Cu, ○ = O, = N.