Question

$\left[NiC{l}_2\right\{P\left(C_2{H}_5{)}_2\right(C_6{H}_5\left){\}}_2\right]$ exhibits temperature dependent magnetic behaviour (paramagnetic/ diamagnetic). The coordination geometries of $N{i}^{2+}$ in the paramagnetic and diamagnetic states are respectively:

• A. tetrahedral and tetrahedral
• B. square planar and square planar
• C. tetrahedral and square planar
• D. square planar and tetrahedral

Answer 1

Answer: (C)

tetrahedral and square planar

$Ni\to \left[Ar\right]4s^{2}3d^8$

$N{i}^{2+}\to \left[Ar\right]3d^8$

Low spin complex: $ds{p}^2$ - square planar (diamagnetic)

High spin complex: $s{p}^3$ - tetrahedral. (paramagnetic)