Bonding Types for the Dioxygen Ligand

In order to systematise the literature, the following classification is used with respect to the metal dioxygen bonding orientations found in oxygen carriers. 

Type 1. Bridging adducts (see Fig. 2), where the dioxygen ligand is bridged between two metal atoms intermolecularly. Here, the metal dioxygen ratio is invariably 2 1. 

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