${\mathrm{O}}_3$ molecule is bent.

${\mathrm{O}}_2{ \mathrm{N}}^{-}$ and  ONF is isoelectronic 

${\mathrm{OF}}_2$ is an oxide of fluorine.

${\mathrm{Cl}}_2{\mathrm{O}}_7$ is anhydride of perchloric acid