Question

Which of the following complex compound exhibits cis-trans isomerism?

• A. $\left[CoCl\right(N{H}_3{)}_4\left(H_{2}O\right)]$
• B. $\left[CoC{l}_3\right(N{H}_3{)}_3]$
• C. $\left[CoC{l}_2\right(N{H}_3{)}_4]$
• D. All of these

Answer 1

Answer: (D)

All of these

All the three complexes exhibit cis trans isomerism.
In the cis isomer of $\left[CoCl\right(N{H}_3{)}_4\left(H_{2}O\right)]$, water and chlorine ligands are adjacent to each other. In the trans isomer, they are opposite to each other.
In the cis (or fac) isomer of $\left[CoC{l}_3\right(N{H}_3{)}_3]$, the three chlorine ligands are present on one triangular face and three ammonia ligands are present on opposite triangular face. In the trans isomer the there ligands are present on the edges and the three ammonia ligands are present on the opposite edges.
In the cis isomer of $\left[CoC{l}_2\right(N{H}_3{)}_4]$, two chlorine ligands are adjacent to each other. In the trans isomer, they are opposite to each other.