d
\(\left[\begin{array}{cc}{\left[{Mn}({CN})_{6}\right]^{3-}} \quad {\left[{Fe}({CN})_{6}\right.}\end{array}\right]^{3-} \quad\left[{Co}\left({C}_{2} {O}_{4}\right)_{3}\right]^{3-}\)

\(\quad\quad\downarrow\)

\({Mn}^{3+} {CN}^{-} \quad {Fe}^{3+}, {CN}^{-} \quad {Co}^{3+}, {C}_{2} {O}_{4}^{2-}\)

\({d}^{4}\) configuration, \(SFLd^{5}\) configuration, \(SFL d^6\) configuration, Chelatingligand

\(\Rightarrow\) All will have larger splitting hence \(d^{2} {sp}^{3}\) hybridisation.

\(\left[{MnCl}_{6}\right]^{3-} \quad\) and \(\quad\left[{FeF}_{6}\right]^{3-}\)

\({d}^{4}\) configuration, \({Cl}^{-} \quad {d}^{5}\) configuration, \({F}^{-}\)

\(\underline1\, \underline{} \quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad \underline1\, \underline{1}\)

\(\underline1\, \underline{1}\,\underline{1} \quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad \underline1\, \underline{1}\,\underline{1}\)

\(4 \text { unpaired electrons } \quad\quad5 \text { unpaired electrons }\)