Question

The complex $\left[Pt\right(N{H}_3{)}_4{]}^{2+}$ has ______ structure:

• A. pentagonal
• B. tetrahedral
• C. square planar
• D. pyramidal

Answer 1

The correct option is C

square planar

Determining the hybridisation of $\left[Pt\right(N{H}_3{)}_4{]}^{2+}$

The name of $N{H}_3$ is ammine and it is a monodentate neutral ligand.

The charge on $N{H}_3$ is $0.$

Let the oxidation state of $Pt$ be ${}^{\prime }{x}^{\prime }$.

$x+4\times \left(0\right)=+2$

$x=+2$

The electronic configuration of $Pt$ is $\left[Xe\right]4f^{14}5d^{9}6s^1.$

The electronic configuration of $P{t}^{2+}$ is $\left[Xe\right]4f^{14}5d^{8}6s^0$

For heavier metals, irrespective of the type of ligand, pairing takes place because of higher $Z_{eff}$ of the heavier metals.

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The hybridisation of $\left[Pt\right(N{H}_3{)}_4{]}^{2+}$ is $ds{p}^2$. Hence, the geometry of the complex is square planar.

Structure of $\left[Pt\right(N{H}_3{)}_4{]}^{2+}$

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So, option (A) is the correct answer.