Question

The IUPAC name of the complex compound [CoCl$_2$(en)$_2$]Cl is:

• A. Dichloridobis(ethane-1,2-diamine)cobalt(III) chloride
• B. Dichloridobis(ethane-2,1-diamine)cobalt(III) chloride
• C. Dichloridobis(ethylenediamine)cobalt(III) chloride
• D. Bis(ethylenediamine)cobalt(III) chloride

Hint:

When naming coordination compounds, remember to use the IUPAC names of ligands, such as "ethane-1,2-diamine" instead of common names like "ethylenediamine."

Answer 1

The Correct Option is A

• The complex contains 2 chloride ions and 2 ethylenediamine (en) ligands.
• Ethylenediamine is a bidentate ligand, also called ethane-1,2-diamine in IUPAC naming.
• The oxidation state of cobalt in the complex ion is +3, so it is cobalt(III).
• The anionic part outside the complex is chloride.
• Thus, the correct IUPAC name is Dichloridobis(ethane-1,2-diamine)cobalt(III) chloride.