Question

The total number of optically active isomers of dichloridobis(glycinato)cobalt(III) ion is ________.

Hint:

In octahedral complexes with bidentate ligands, only the cis form can show optical activity.

Answer 1

Correct Answer: 6

Step 1: Identify coordination geometry.
The complex is [Co(gly)$_2$Cl$_2$]$^-$, where gly = glycinate (bidentate ligand). Co(III) forms an octahedral complex with two bidentate (gly) and two monodentate (Cl) ligands.
Step 2: Types of isomerism.
This complex can exhibit:
- Geometrical isomerism (cis and trans forms).
- The cis form is optically active due to lack of symmetry, while the trans form is optically inactive (has a plane of symmetry).
Step 3: Count optical isomers.
The cis form has two non-superimposable mirror images (enantiomers).
Step 4: Conclusion.
Therefore, the number of optically active isomers is 2.