where \(\varepsilon_{\mathrm{a}} \Rightarrow\) absorbed energy (splitting energy)
\(\lambda_{\mathrm{a}} \Rightarrow\) absorbed wavelength
Presence of \(\mathrm{SFL} \Rightarrow \varepsilon_{\mathrm{a}}(\uparrow) \lambda_{\mathrm{a}}(\downarrow)\)
\(\mathrm{H}_{2} \mathrm{O}<\mathrm{NH}_{3}<\) en ligand strength \(\uparrow\) splitting energy \(\uparrow\) so absorbed \(\lambda \downarrow\)
$\operatorname{cis}-\left[\mathrm{Cr}(\mathrm{ox})_2 \mathrm{Cl}_2\right]^{3-},\left[\mathrm{Co}(\mathrm{en})_3\right]^{3+}$
$\operatorname{cis}-\left[\mathrm{Pt}(\mathrm{en})_2 \mathrm{Cl}_2\right]^{2+}, \text { cis }-\left[\mathrm{Co}(\mathrm{en})_2 \mathrm{Cl}_2\right]^{+}$
$\text {trans }-\left[\mathrm{Pt}(\mathrm{en})_2 \mathrm{Cl}_2\right]^{2+}, \text { trans }-\left[\mathrm{Cr}(\mathrm{ox})_2 \mathrm{Cl}_2\right]^{3-}$