Target Exam

CUET

Subject

Chemistry

Chapter

Inorganic: Coordination Compounds

Question:

Which of the following complexes is heteroleptic?

Options:

$[Fe(NH_3)_4Cl_2]^+$

$[Cr(NH_3)_6]^{3+}$

$[Co(NH_3)_6]^{3+}$

$[Mn(CN)_6]^{4-}$

Correct Answer:

$[Fe(NH_3)_4Cl_2]^+$

Explanation:

The correct answer is Option (1) → $[Fe(NH_3)_4Cl_2]^+$

In coordination chemistry, complexes are classified into two types based on the nature of their ligands:

  • Homoleptic complexes: The metal is bound to only one type of donor group (ligand).
  • Heteroleptic complexes: The metal is bound to more than one type of donor group (ligand).

Analysis of the Options:

  • $[Fe(NH_3)_4Cl_2]^+$: This complex contains two different types of ligands: four ammine ($NH_3$) groups and two chloride ($Cl^-$) ions. Because there is more than one type of ligand, it is heteroleptic.
    • showing two types of ligands]
  • $[Cr(NH_3)_6]^{3+}$: This complex contains only one type of ligand (six $NH_3$ groups). It is homoleptic.
  • $[Co(NH_3)_6]^{3+}$: This complex contains only one type of ligand (six $NH_3$ groups). It is homoleptic.
  • $[Mn(CN)_6]^{4-}$: This complex contains only one type of ligand (six $CN^-$ groups). It is homoleptic.