The compound \([Co(en)_3][Cr(C_2O_4)_3]\) is a coordination complex. The name can be derived from the ligands and their coordination to the central metal ions.
-
The \([Co(en)_3]^{3+}\) part is a cobalt complex where "en" stands for ethylenediamine, a bidentate ligand. Cobalt is in the +3 oxidation state here.
-
The \([Cr(C_2O_4)_3]^{3-}\) part involves chromium with three oxalate (\(C_2O_4^{2-}\)) ligands, where chromium is also in the +3 oxidation state.
Putting it all together, the name of the compound is:
Tris(ethylenediamine)cobalt(III) chromium(III) tris(oxalate).
In a more condensed form, it can be referred to as tris(ethylenediamine)cobalt(III) chromium(III) oxalate.