The IUPAC name of [CoCl_2(en)_2]Cl complex is:

The correct answer is Option (1) → Dichloridobis(ethane-1,2-diamine)cobalt(III) chloride

The complex is [CoCl₂(en)₂]Cl:

en = ethane-1,2-diamine, a neutral bidentate ligand

Cl₂ inside the coordination sphere are chlorido ligands

Core Concept

Complex = [CoCl₂(en)₂]Cl

Outer Cl⁻ is counter ion → complex inside bracket carries +1 charge.

Let oxidation state of Co = x

x + 2(−1) + 2(0) = +1

x − 2 = +1

x = +3

So metal = cobalt(III)

Ligands

Cl⁻ → chlorido

en → ethane-1,2-diamine

Number of ligands:

2 Cl⁻ → dichlorido

2 en → bis(ethane-1,2-diamine)

Alphabetical order (ignoring prefixes):

chloridoethane-1,2-diamine

So naming order:

dichloridobis(ethane-1,2-diamine)

Final Name

Dichloridobis(ethane-1,2-diamine)cobalt(III) chloride