Question

Explain, the nature of $S-O$ bond in ${SO}_2$.

Answer 1

The electronic configuration of $S$ is $1s^{2}2s^{2}2p^{6}3s^{2}3p^4.$

During the formation of $S{O}_2,$ one electron from $3p$ orbital goes to the $3d$ orbital and $S$ undergoes $s{p}^2$ hybridization. Two of these orbitals form sigma bonds with two oxygen atoms and the third contains a lone pair. $p-$orbital and $d-$orbital contain an unpaired electron each. One of these electrons forms $p\pi -p\pi$ bond with one oxygen atom and the other forms p π- d π bond with the other oxygen. This is the reason $S{O}_2$ has a bent structure. Also, it is a resonance hybrid of structures I and II.

Both $S-O$ bonds are equal in length (143 pm) and have a multiple bond character.