Which of the following compounds exhibits linkage isomerism

Options

(a) [Co(en)₃]Cl₃
(b) [Co(NH₃)₆][Cr(en)₃]
(c) [Co(en)₂(NO₂)Cl]Br
(d) [Co(NH₃)₅Cl]Br₂

Correct Answer:

[Co(en)₂(NO₂)Cl]Br

Explanation:

This type of isomerism occurs in complex compounds which contain ambidentate ligands like NO₂⁻, SCN⁻, CN⁻, S₂O₃²⁻ and CO. These ligands have two donor atoms but at a time only one atom is directly linked to the central metal atom of the complex.