Transition metal dioxygen complex

[1][2] The study of these compounds is inspired by oxygen-carrying proteins such as myoglobin, hemoglobin, hemerythrin, and hemocyanin.

[4] The binding of O2 is the first step in many important phenomena, such as cellular respiration, corrosion, and industrial chemistry.

As shown by the mechanisms of cytochrome P450 and alpha-ketoglutarate-dependent hydroxylase, Fe-η1-O2 bonding is conducive to formation of Fe(IV) oxo centers.

O2 can bind to one metal of a bimetallic unit via the same modes discussed above for mononuclear complexes.

A well-known example is the active site of the protein hemerythrin, which features a diiron carboxylate that binds O2 at one Fe center.

Dinuclear complexes can also cooperate in the binding, although the initial attack of O2 probably occurs at a single metal.

Salcomine, the cobalt(II) complex of salen ligand is the first synthetic O2 carrier.

A picket-fence porphyrin complex of Fe, with axial coordination sites occupied by methylimidazole (green) and dioxygen (R = amide groups). [ 6 ]
O 2 -bound form of hemocyanin, the O 2 carrier for certain molluscs.
Structure of [Co(salen)( dmf )] 2 O 2 . [ 11 ]
Oxidation of the dicobalt peroxy complex gives the complex of superoxide (O 2 − ). The Co-O-O-Co core flattens in the process and the O-O distance contracts by 10%.