Which among the complexes $\left[\mathrm{Co}(\mathrm{CN})_6\right]^{4-} \cdot\left[\mathrm{Cr}\left(

Question

Which among the complexes $\left[\mathrm{Co}(\mathrm{CN})_6\right]^{4-} \cdot\left[\mathrm{Cr}\left(\mathrm{NH}_3\right)_6\right]^{3+}$ exhibit Jahn-Teller distortion?

Professor PC Thomas Classes · Answer

$[\mathrm{Co}(\mathrm{CN})_6]^{4-}$ is a $d^7$ low-spin complex, leading to asymmetric degenerate $e_g$ filling, causing Jahn-Teller distortion.