Question

Low spin complex of $d^6$ cation in an octahedral field will have the following energy

• A.
• B.
• C.
• D.

Answer 1

The correct option is D

$d^6$ cation low spin will have electronic configuration: $t_2{g}^{6}e{g}^0$

CFSE = (–0.4x + 0.6y) ${\Delta }_0$

$=(-\frac{2}{5}x+\frac{3}{5}y){\Delta }_0$

x is number of electrons in $t_{2}g=6$

y is number of electrons in eg = 0

$=(-\frac{2}{5}x+6+\frac{3}{5}\times 0){\Delta }_0=\left(\frac{-12}{5}\right){\Delta }_0$

Number of electron pairs = 3, $\therefore$ Pairing energy = 3P

$=\frac{-12}{5}{\Delta }_0+3P$