Question

Answer the question on the basis of the passage given below:
Transition metals form a large number of complexes or coordination compounds in which the metal atoms are bound to a number of anions or neutral molecules. The valence bond theory explains the formation, magnetic behaviour, and geometrical shapes, while the crystal field theory explains the effect of different crystal fields on the degeneracy of \(d\)-orbitals energies of the central metal atom/ion. This provides for the quantitative estimation of orbital separation energies, magnetic moments, and spectral and stability parameters.
The compound \( \left[\text{Pt(NH}_3)_2\text{Cl}_2\right] \) exhibits:

• A. Geometrical isomerism
• B. Linkage isomerism
• C. Ionisation isomerism
• D. Coordination isomerism

Hint:

Geometrical isomerism occurs when ligands can be arranged in different spatial positions around the metal ion. In the case of \( \left[\text{Pt(NH}_3)_2\text{Cl}_2\right] \), the cis and trans forms are examples of geometrical isomerism.

Answer 1

The Correct Option is A

Let’s examine the isomerism exhibited by \( \left[\text{Pt(NH}_3)_2\text{Cl}_2\right] \): 
- Geometrical Isomerism (1): This compound exhibits geometrical isomerism (cis-trans isomerism). In the complex \( \left[\text{Pt(NH}_3)_2\text{Cl}_2\right] \), the two chloride ions and the two ammonia molecules can arrange themselves in different spatial configurations, either cis or trans. The cis-isomer has both chloride ions adjacent to each other, while the trans-isomer has the chloride ions opposite each other. - Cis: The chloride ions are adjacent to each other. - Trans: The chloride ions are opposite to each other. 
- Linkage Isomerism (2): Linkage isomerism occurs when a ligand can bind through two different atoms. For example, NO₂⁻ can bind to the metal center through the nitrogen atom or the oxygen atom. In the given complex \( \left[\text{Pt(NH}_3)_2\text{Cl}_2\right] \), there is no possibility of linkage isomerism since chloride and ammonia ligands do not have two binding sites. 
- Ionisation Isomerism (3): Ionisation isomerism occurs when a coordination compound has the same molecular formula but gives different ions in solution. In this case, the complex \( \left[\text{Pt(NH}_3)_2\text{Cl}_2\right] \) does not exhibit ionisation isomerism, as no other ions are produced in solution. 
- Coordination Isomerism (4): Coordination isomerism occurs when the metal ions in the coordination sphere can switch places. However, this complex does not exhibit coordination isomerism, as there is only one metal ion in the coordination sphere. 
Thus, the correct answer is Option (1), as the complex exhibits geometrical isomerism.