Question

Which of the following is an example of coordination isomerism?

• A. $ [Co(NH_{3})_{3}(H_{2}O)_{2}Cl]Br_{2}$
• B. $ [Co(NH_{3})_{6}][Cr(C_{2}O_{4})_{3}]$
• C. $ [Co(NH_{3})_{5}NO_{3}]SO_{4}$
• D. $ [Pt(NH_{3})_{4}Cl_{2}]Br_{2}$

Answer 1

Answer: (B)

Coordination isomerism occurs when both cation and anion are complex. This isomerism is caused by the interchange of ligands between the two complex ions, e.g.
$[Co(NH_{3})_{6}][Cr(C_{2}O_{4})_{3}]$
$[Cr(NH_{3})_{6}][Co(C_{2}O_{4})_{3}]$