Question

A coordination complex of type $M{X}_2{Y}_2$ ($M-$ metal ion; $X,Y$- monodentate ligands), can have either a tetrahedral or a square planar geometry. The maximum number of possible isomers in these two cases are respectively.

• A. $1$ and $2$
• B. $2$ and $1$
• C. $1$ and $3$
• D. $3$ and $2$

Answer 1

Answer: (A)

$1$ and $2$

In tetrahedral $M{X}_2{Y}_2$ all the positions are adjacent to each other.
Hence, only one isomer is possible.

In the square planar $M{X}_2{Y}_2$ two isomers cis and trans are possible.
In the cis isomer, two X ligands are adjacent to each other and in the trans isomer, they are opposite to each other.