Metal carbonyls polypyridines

Spectroelectrochemical (EPR, UV Vis, res. Raman, and to a lesser extent IR) characterization of redox products often reveals features characteristic of reduced polypyridine ligands for ligand-localized reductions or of oxidized metal atoms for metal-centered oxidations. Stretching CO frequencies, obtained by IR spectroelectrochemistry, are an especially useful marker of a metal oxidation state in carbonyl-polypyridine complexes. 

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