Question

What is the structure of ${\mathrm{IF}}_7$?

Answer 1

Step 1: Hybridization:

• “Hybridization is defined as the process of intermixing of the orbitals of slightly different energies so as to redistribute their energies, resulting in the formation of a new set of orbitals of equivalent energies and shape.”

Step 2: Formula used for calculation:

• $\mathrm{Steric}\mathrm{number}=\frac{1}{2}\left[\mathrm{V}+\mathrm{M}-\mathrm{C}+\mathrm{A}\right]$
• Where V is the number of valence electrons of a metal atom, M is the monovalent electron, C is the positive charge and A represents the negative charge.

Step 3: Calculation for Hybridisation of ${\mathrm{IF}}_7$:

• The total number of valence electrons in ${\mathrm{IF}}_7$ is $7$ and there are $7$ monovalent atoms.
• $$\begin{gathered} \mathrm{Steric}\mathrm{number}=\frac{1}{2}\left[7+7\right]=\frac{1}{2}\times 14 \\ \mathrm{Steric}\mathrm{number}=7 \end{gathered}$$
• The steric number is $7$, thus the hybridization of ${\mathrm{IF}}_7$ is ${\mathrm{sp}}^3{\mathrm{d}}^3$.

Step 4: Structure and shape of ${\mathrm{IF}}_7$:

• As per VSEPR theory, the ${\mathrm{sp}}^3{\mathrm{d}}^3$ hybridization has a pentagonal bipyramidal geometry.
• The structure of ${\mathrm{IF}}_7$ is given below: