Structure and bonding in dioxygen complexes

In his review Vaska [26] was the first to give a classification scheme for dioxygen complexes known at that time. It was based on the geometry of the metal-dioxygen moiety and the formal charge on the 0  

The vast majority of known dioxygen complexes directly synthesized using 0 contains cobalt, iron, manganese, rhodium or iridium as the 

There have been numerous x-ray structure determinations of dioxygen complexes. Tables VI - X give a list of the most important structural data for dioxygen complexes grouped according to Vaska s classification scheme. 

Structural data for mononuclear end-on superoxo complexes (Vaska s type la) 

Iron and cobalt are the predominant metals among the end-on superoxo complexes. This geometry has been established beyond doubt. The 0-0 bond length is in most of the cases in the range of 1.21 - 1.28 X, which is somewhat shorter than the 1.32 X found for superoxide salts, but longer than the 1.21 X in free 0. In a number of cases, 

Species Bond order 0-0 bond length,A 0-0 vibrational frequency, cm 0-0 bond dissoc n energy, k cal/mole 

ESTABLISHED STRUCTURES OF SOME TRANSITION METAL PEROXO COMPLEXES 

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