Vibrational bands attributable to carbonate ion: after examining the spectra and reading the appropriate references make assignments of the vibrational modes attributable to the carbonate ion in your spectrum. what evidence in the spectra would allow you to conclude that the carbonate is acting as a bidentate ligand in the cobalt complex rather than being present as either a monodentate ligand or a free, uncoordinated anion. hint: see the nakamoto, fujita, tanaka, and kobayashi reference.