Cobalt spectroscopic terms

Some representative spectral data are given in Table VI. The spectroscopic properties of /x-hydroxo-/i-peroxo and -hydroxo/x-superoxo dicobalt(III) complexes have recently been reviewed by Fallab and Mitchell (119) and seem reasonably well rationalized in terms of the molecular orbital (MO) models formulated by Lever and Gray (120). The spectra of -hydroxo -/x-peroxo and /i-hydroxo-/i-superoxo complexes of rhodium(III) show features similar to those of the cobalt(III) species (121-124). 

Some efforts have been made to interpret the spectroscopic and magnetic properties of cobalt enzymes in terms of coordination geometry and chemical identity of ligands. The basis of these attempts is a comparison with the corresponding properties of low-molecular weight complexes of known structure. A brief summary of relevant data on some models is given in the following section. 

The electronic structure, in particular the electronic spectroscopic properties, of the whole class of cobalt amine complexes may be reduced to a discussion of the central Co-Ne core. This disregards, of course, the charge-transfer transition that in these compexes typically occurs around 250 nm. The geometrical structure is either octahedral or is defined in terms of a subgroup of the cubic point group Oh, where the... 

A particularly important derivative of the [Co(CO)4] anion is the hydrogen derivative, HCo(CO)4. Although this compound is commonly called cobalt carbonyl hydride , the term hydride is actually a misnomer since the hydrogen atom in HCo(CO)4 is not hydridic but strongly protonic in character HCo(CO)4 is as strong an acid as sulfuric acid (9S). Because of its unusual properties and relative simplicity, HCo(CO)4 has been the subject of several spectroscopic (225, 228, 229) and theoretical 230) investigations. 

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