The IUPAC name of \( \text{K}_3[\text{Co}(\text{C}_2\text{O}_4)_3] \) is Potassium trioxalatocobaltate(III).
The oxalate anion ( \( \text{C}_2\text{O}_4^{2-} \) ) is a bidentate ligand, and the prefix "tri" indicates there are three oxalate ligands.
The complex anion is \( [\text{Co}(\text{C}_2\text{O}_4)_3]^{3-} \), and since the potassium ion has a +1 charge, there must be three potassium ions to balance the charge.
The oxidation state of cobalt is +3, indicated by the Roman numeral (III).
Consider the following complexes:
(A) [Co(CN)$_6$]$^{3-}$
(B) [Co(NH$_3$)$_5$H$_2$O]$^{3+}$
(C) [Co(H$_2$O)$_6$]$^{3+}$
(D) [CoF$_6$]$^{3-}$
The wavelength absorbed by the above complexes are in the order:
Nomenclature of Coordination Compounds is important in Coordination Chemistry because of the need to have an unambiguous method of describing formulas and writing systematic names, particularly when dealing with isomers.