In which of the following ions, $\mathrm{d-d}$ transition is not possible ?
In which of the following ions, $\mathrm{d-d}$ transition is not possible ?
$\mathrm{Ti}^{4+}$
$\mathrm{Cr}^{3+}$
$\mathrm{Mn}^{2+}$
$\mathrm{Cu}^{2+}$
Solution
Due to absence of $\mathrm{d}$-electron in $\mathrm{Ti}^{4+}\left([\mathrm{Ar}]^{18} 3 \mathrm{d}^{0} 4 \mathrm{s}^{0}ight), \mathrm{d}-\mathrm{d}$ transition is not possible.