Coordination Compounds

A square planar complex of the type Mabcd, where a, b, c and d are unidentate ligands, exhibits geometrical isomerism and exists in one cis-form and two trans-forms.

[\(\mathrm{Co}\left(\mathrm{NH}_3\right)_5 \mathrm{NO}_2\)] Cl₂ exists in 2 forms, the red form and the yellow form which are linkage isomers.

\(\left[\mathrm{Fe}(\mathrm{CN})_6\right]^{3-}\) is called a Low spin complex.

Out of cis- \(\left[\mathrm{CrCl}_2(\mathrm{ox})_2\right]^{3-}\) and trans- \(\left[\mathrm{CrCl}_2(\mathrm{ox})_2\right]^{3-}\), the trans isomer is optically inactive.