Question

Consider that d⁶ metal ion (M²⁺) forms a complex with aqua ligands and the spin only magnetic moment of the complex is 4.90 BM. The geometry and the crystal field stabilization energy of the complex are ______.

पर्याय

• Tetrahedral and −1.6 Δ_t + 1P

• Octahedral and −2.4 Δ_o + 2P

• Tetrahedral and −0.6 Δ_t

• Octahedral and −1.6 Δ_o

Answer 1

Consider that d⁶ metal ion (M²⁺) forms a complex with aqua ligands and the spin only magnetic moment of the complex is 4.90 BM. The geometry and the crystal field stabilization energy of the complex are tetrahedral and −0.6 Δ_t.

Explanation:

`sqrt(n(n + 2))` = 4.9

⇒ n(n + 2) = 24

⇒ n² + 2n − 24 = 0

⇒ (n + 6) (n − 4) = 0

n = 4

No. of unpaired electrons = 4

Since the spin-only magnetic moment is 4.90 BM. As a result, ions must have a total of four unpaired electrons. If the complex is octahedral, it must be high spin, with the configuration t_2g^2,1,1 e_g^1,1.

CFSE = 4 × (−0.4 Δ_o) + 2 × 0.6 Δ_o

= −1.6 Δ_o + 1.2 Δ_o

= −0.4 Δ_o

If the compound is tetrahedral, the electronic configuration is e_g^2,1 t_2g^1,1,1.

CFSE = 3 × (−0.6 Δ_t) + 3 × (0.4 Δ_t)

= −1.8 Δ_t  + 1.2 Δ_t

= −0.6 Δ_t