Question

Which of the following can show coordination isomerism? (1) $ [Cu{{(N{{H}_{3}})}_{4}}][PtC{{l}_{4}}] $ (2) $ {{[Fe{{(N{{H}_{3}})}_{6}}]}_{2}}{{[Pt{{(CN)}_{6}}]}_{3}} $ (3) $ [Co{{(N{{H}_{3}})}_{6}}][Cr{{({{C}_{2}}{{O}_{4}})}_{3}}] $ (4) $ [Pt{{(en)}_{3}}]{{(S{{O}_{4}})}_{2}} $

• A. 1, 2 and 3 are correct.
• B. 1 and 2 are correct.
• C. 2 and 4 are correct.
• D. 1 and 3 are correct.

Answer 1

Answer: (D)

The compounds in which cation and anion both are complex and metals have same coordination number, exhibit coordination isomerism. It involves the exchange of ligands between cation and anion. (i) $ \left. \begin{align} & [Cu{{(N{{H}_{3}})}_{4}}][PtC{{l}_{4}},] \\ & [CuC{{l}_{4}}][Pt{{(N{{h}_{3}})}_{4}}] \\ \end{align} \right\}(coordination\,isomers) $ $ C.N.=4 $ (ii) $ \left. \begin{align} & [Co{{(N{{H}_{3}})}_{6}}][Cr{{({{C}_{2}}{{O}_{4}})}_{3}}], \\ & [Co{{({{C}_{2}}{{O}_{4}})}_{3}}][Cr{{(N{{H}_{3}})}_{6}}] \\ \end{align} \right\}(coordination\,isomers) $ $ C.\text{ }N=6[\because {{C}_{2}}{{O}_{4}}is\text{ }bidentate\text{ }ligand] $