Question

The d-electron configuration of $[Ru(en)_{3}]Cl_{2}$ and $\left[ Fe \left( H _{2} O \right)_{6}\right] Cl _{2}$, respectively are:

• A. $t _{2 g }^{4} e _{ g }^{2}$ and $t _{2 g }^{6} e _{ g }^{0}$
• B. $t _{2 g }^{6} e _{ g }^{0}$ and $t _{2 g }^{6} e _{ g }^{0}$
• C. $t _{2 g }^{6} e _{ g }^{0}$ and $t _{2 g }^{4} e _{ g }^{2}$
• D. $t _{2 g }^{4} e _{ g }^{2}$ and $t _{2 g }^{4} e _{ g }^{2}$

Answer 1

Answer: (C)

$[Ru(en)_{3}]Cl_{2}$ $\quad$ $ Ru \Rightarrow 4d$ series

en $\Rightarrow $ chelating ligand

$CN =6$, octahedral splitting hence large splitting of d-subshell



$\left[ Fe \left( H _{2} O \right)_{6}\right] Cl _{2} \Rightarrow H _{2} O \Rightarrow $ Weak filled ligand

$Fe ^{+2} \Rightarrow [ Ar ] \,3d ^{6} 4s ^{0}$ less splitting

$CN =6$ octahedral splitting