Question

Based on Valence Bond Theory, explain the geometry and magnetic character of [NiCl$_4$]$^{2-$. [Atomic number: Ni = 28]}

Hint:

In tetrahedral complexes, the metal ion undergoes sp$^3$ hybridization, leading to specific geometry and magnetic properties.

Answer 1

According to Valence Bond (VB) Theory, the geometry and magnetic properties of the complex depend on the hybridization and the number of unpaired electrons in the central metal ion. In [NiCl$_4$]$^{2-}$, Ni$^{2+}$ has the electron configuration 3d$^8$4s$^0$. The central Ni$^{2+}$ ion undergoes sp$^3$ hybridization with four chloride ions, forming a tetrahedral geometry. Since all electrons are paired in the d-orbitals of Ni$^{2+}$, [NiCl$_4$]$^{2-}$ is diamagnetic.