Question

The cis-isomer of which of the following ions will have optical isomers but the trans-isomer will not?

• A. $\left[CoC{l}_2\right(en{)}_2{]}^{+}$
• B. $\left[CoC{l}_2\right(N{H}_3{)}_4{]}^{+}$
• C. $\left[Cr\right(NCS{)}_4(N{H}_3{)}_2{]}^{-}$
• D. $\left[Cr\right(NCS{)}_2(N{H}_3{)}_4{]}^{+}$

Answer 1

The correct option is A $\left[CoC{l}_2\right(en{)}_2{]}^{+}$

Its cis compound is optically active but as trans has plane of symmetry so its optically inactive.
Other compounds are optically inactive due to presence of symmetry.