Question

Which of the following give maximum number of isomers?

Options

• [Co(NH₃)₄Cl₂]

• [Ni(en)(NH₃)₄]²⁺

• [Ni(C₂O₄)(en)₂]

• [Cr(SCN)₂(NH₃)₄]²⁺

Answer 1

[Cr(SCN)₂(NH₃)₄]²⁺

Explanation:

The ambidentate character of the thiocyanate (SCN) ligand causes this combination to display both geometrical (cis/trans) and linkage isomerism. The SCN ligand can attach to either sulfur or nitrogen, resulting in several isomers. As a result, it has two linkage isomers, each of which can exist in both cis and trans forms, totalling four isomers.

The other complex, [Ni(C₂O₄)(en)₂]²⁻, is also capable of geometric and optical isomerism, but the number of isomers generated is fewer than that of [Cr(SCN)₂(NH₃)₄]²⁺.