Which of the following interhalogen compounds, ${\text{IF}}_3$, ${\text{IF}}_5$, ${\text{IF}}_7$, or $\text{ClF}$, is known to exist in a bent T-shaped geometry?

Solution

1. The central iodine atom in ${\text{IF}}_3$ has $7$ valence electrons.
2. Three electrons are used for bonding with fluorine atoms, leaving $4$ electrons as $2$ lone pairs.
3. The steric number is $3 + 2 = 5$, corresponding to trigonal bipyramidal electron geometry.
4. With $2$ lone pairs in equatorial positions, the molecular geometry is T-shaped.
5. Hence the answer is (C).