Q14 / 180 · COMEDK 2023 (Morning Shift) · Chemistry
The complex $\left[\mathrm{PtCl}_2(\mathrm{en})_2\right]^{2+}$ ion shows
- Correct answerAgeometrical and optical isomerism
- Bgeometrical isomerism only
- Cstructural isomerism
- Doptical isomerism only
Solution
The complex $\left[\mathrm{PtCl}_2(\mathrm{en})_2\right]^{2+}$ has a coordination number of 6, indicating an octahedral geometry. The ligands are two chloride ions and two ethylenediamine (en) molecules, which are bidentate.
The complex can exist in two geometrical forms: the cis-isomer and the trans-isomer. In the trans-isomer, the two chloride ligands are at 180 degrees to each other, resulting in a plane of symmetry, which makes it achiral (optically inactive).
In the cis-isomer, the two chloride ligands are at 90 degrees to each other. The cis-isomer lacks a plane of symmetry and a center of inversion, making it chiral. Therefore, the cis-isomer exists as a pair of enantiomers (optical isomers).
Since the complex exhibits both geometrical isomerism (cis and trans) and optical isomerism (for the cis form), it shows both types of isomerism.
Answer: geometrical and optical isomerism
The complex can exist in two geometrical forms: the cis-isomer and the trans-isomer. In the trans-isomer, the two chloride ligands are at 180 degrees to each other, resulting in a plane of symmetry, which makes it achiral (optically inactive).
In the cis-isomer, the two chloride ligands are at 90 degrees to each other. The cis-isomer lacks a plane of symmetry and a center of inversion, making it chiral. Therefore, the cis-isomer exists as a pair of enantiomers (optical isomers).
Since the complex exhibits both geometrical isomerism (cis and trans) and optical isomerism (for the cis form), it shows both types of isomerism.
Answer: geometrical and optical isomerism
Hence, the correct answer is option: 'A'.