Reversible Scavenging of Dioxygen from Air by a Copper Complex

We report that exposing the dipyrrin complex (L-EMind)Cu(N-2) to air affords rapid, quantitative uptake of O-2 in either solution or the solid-state to yield (L-EMind)Cu(O-2). The air and thermal stability of (L-EMind)Cu(O-2) is unparalleled in molecular copper-dioxygen coordination chemistry, attributable to the ligand flanking groups which preclude the [Cu(O-2)](1+) core from degradation. Despite the apparent stability of (L-EMind)Cu(O-2), dioxygen binding is reversible over multiple cycles with competitive solvent exchange, thermal cycling, and redox manipulations. Additionally, rapid, catalytic oxidation of 1,2-diphenylhydrazine to azoarene with the generation of hydrogen peroxide is observed, through the intermittency of an observable (L-EMind)Cu(H2O2) adduct. The design principles gleaned from this study can provide insight for the formation of new materials capable of reversible scavenging of O-2 from air under ambient conditions with low-coordinate CuI sorbents.

Automated summary

The study found that (L-EMind)Cu(O-2) exhibits exceptional air and thermal stability in molecular copper-dioxygen coordination chemistry, with the O-2 binding being reversible. Additionally, it plays a crucial role in catalytic oxidation reactions.