$p\pi -d\pi$ bonding occurs between oxygen and :

$p\pi -d\pi$ occurs in ${\mathrm{P}}_4{\mathrm{O}}_{10}$ , ${\mathrm{XeO}}_2{\mathrm{F}}_2$ and ${\mathrm{SO}}_2$.

The p-orbital in ${\mathrm{XeO}}_2{\mathrm{F}}_2$ comes from the $\mathrm{O}$ atom, whereas the d-orbital comes from the $\mathrm{Xe}-$ atom. The terminal P-O bonds in ${\mathrm{P}}_4{\mathrm{O}}_{10}$ are created through $p\pi -d\pi$-back bonding. The quantity of $p\pi -d\pi$ bonds found in ${\mathrm{SO}}_2$.