The low spin complex of `d^(6)` metal ion in an octahedral field will have the following CFSE :

Options

A. `-2/5Delta_0 + 2P`
B. `-2/5Delta_0 + P`
C. `-12/5 Delta_0 + P`
D. `-12/5Delta_0 + 3P`

Answer

D

Explanation

Electronic configuration of `d^6`-cation in low spin `= t_(2g)^6e_g^theta`
`CFSE = (-0.4 xx 0.6y)Delta_0 = (-2/5 x + 3/5y) Delta_0`
x= number electronsin `t_(2g) = 6` y = number of electrons in `e_(g) = 0`
`:. CFSE =(-2/5 xx 6 + 0) Delta_0 = -12/5 Delta_0`
Number of electron pairs = 3 `:.` pairing energy =3 P
`:.` Energy of low spin `d^6`1 cation `= - 12/5 Delta_0 + 3P`