Which isomer of `[CoCl_(2)(en)_(2)]^(+)` does not show optical isomerism ?

Explanation

To determine which isomer of the coordination compound \([CoCl_2(en)_2]^+\) does not show optical isomerism, we can follow these steps:

### Step 1: Understand the Coordination Compound
The given compound \([CoCl_2(en)_2]^+\) consists of cobalt (Co) as the central metal ion, two chloride ions (Cl), and two ethylenediamine (en) ligands. Ethylenediamine is a bidentate ligand, meaning it can form two bonds with the metal ion.

### Step 2: Identify Possible Isomers
The coordination number of cobalt in this complex is 6 (since it is surrounded by 4 ligands: 2 bidentate en ligands and 2 monodentate Cl ligands). This allows for the formation of different geometric isomers.

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