NEET 2023 Chemistry Complexes MCQ Question

To determine which of the given complexes is a homoleptic complex, we first need to understand the definition of homoleptic and heteroleptic complexes.

Definition:

• Homoleptic Complex: A complex is termed homoleptic if it contains only one type of ligand coordinated to the central metal ion.
• Heteroleptic Complex: A complex is termed heteroleptic if it contains more than one type of ligand.

Analyzing the Options:

A) Diamminechloridonitrito - N - platinum (II)
This complex contains three different ligands: diammine (NH₃), chlorido (Cl⁻), and nitrito (NO₂⁻). Therefore, it is a heteroleptic complex.

B) Pentaamminecarbonatocobalt (III) chloride
This complex includes pentaammine (NH₃) as one ligand and carbonato (CO₃²⁻) as another ligand. The presence of both pentaammine and carbonato means that this complex is also heteroleptic, not homoleptic. Thus, the claim that this is the correct answer is incorrect based on our analysis.

C) Triamminetriaquachromium (III) chloride
In this complex, we have three ammonia (NH₃) ligands and three water (H₂O) ligands. Since there are two different types of ligands present, this complex is also heteroleptic.

D) Potassium trioxalatoferrate (III)
In this case, trioxalatoferrate contains oxalate (C₂O₄²⁻) ligands. However, the oxalate ligand itself is bidentate, meaning it binds to the metal ion through two donor atoms. Despite this, it is important to note that the overall complex still represents a single type of ligand (oxalate) coordinating to iron (Fe). Therefore, this complex can be classified as homoleptic.

Conclusion:

Given the analysis, the correct answer should actually be D, as it is the only homoleptic complex among the options provided. The confusion comes from interpreting the nature of the ligands.

Summary of Clarifications:

• Option A is heteroleptic due to multiple ligand types.
• Option B is heteroleptic as it contains both ammonia and carbonate ligands.
• Option C is also heteroleptic due to the presence of both ammonia and water.
• Option D is homoleptic, as it contains only oxalate ligands coordinating to the iron center.

Final Note:

It is important to carefully analyze the ligands present in coordination complexes to classify them appropriately as homoleptic or heteroleptic. The identification of the ligands and their nature is crucial in coordination chemistry.