Oxygenation of a cobalt(II)-dioxime complex

The ligand 4,4,9,9-tetramethyl-5,8-diazadodecane-2,dione dioxime (LH2) forms cobalt(11) complexes [Co(LH)(H2O)2]+ and [Co(LH)(H2O)OH]; the stabilities of these complexes have been determined in aqueous solution at 25oC (I = 0.10 M NaCl). The hydroxo complex [Co(LH)(H2O)-OH] reacts with dioxygen to give the non-labile oxygen adduct [(H0)(HL)CoO2Co(LH) (OH)] in aqueous solution: this reaction has been followed by polarographic oxygen sensor.