Cc. Cheng et al., DIOXYGEN CHEMISTRY OF NICKEL(II) DIOXOPENTAAZAMACROCYCLIC COMPLEXES -SUBSTITUENT AND MEDIUM EFFECTS, Journal of molecular catalysis. A, Chemical, 113(1-2), 1996, pp. 379-391
Nickel(II) complexes of certain dioxopentaazamacrocycles are known to
react with dioxygen, but the reaction is highly ligand dependent, incl
udes an induction period, and appears to require ligand oxidation conc
omitant with O-2 uptake.