Question

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Number of possible isomers for the complex $\left[Co\right(e{n}_2\left)C{l}_2\right]Cl$ will be (en: ethylenediamine) is :

Re-AIPMT-2015

• A. $4$
• B. $2$
• C. $3$
• D. $1$

Answer 1

The correct option is C $3$

Number of possible geometrical isomers for the complex $\left[Co\right(en{)}_{2}C{l}_2]Cl$ is 2 and are cis and trans.

In $\text{trans}-\left[CoC{l}_2\right(en{)}_2{]}^{+}$ both the (en) are at opposite position and are at same plane. So there will be a plane of symmetry which result in optical inactivity.

In $cis-\left[CoC{l}_2\right(en{)}_2{]}^{+}$, both the (en) ligands are at adjacent position, thus, both at different plane and hence it is optically active and gives a respective non-superimposable mirrow image enantiomer.

Hence, there are totally 3 possible isomers for the given complex.