Chlorine and oxygen can bond in a number of ways:
- chlorine monoxide radical, ClO•, chlorine (II) oxide radical
- chloroperoxyl radical, ClOO•, chlorine (II) peroxide radical
- chlorine dioxide, ClO2, chlorine (IV) oxide
- chlorine trioxide radical, ClO3•, chlorine (VI) oxide radical
- chlorine tetroxide radical, ClO4•, chlorine (VII) oxide radical
- dichlorine monoxide, Cl2O, chlorine (I) oxide
- chlorine peroxide, Cl2O2, dimer of chlorine monoxide radical or ClO dimer, chlorine (I) peroxide
- dichlorine trioxide, Cl2O3 as O−Cl−ClO2, chlorine (III,V) oxide
- dichlorine trioxide, Cl2O3 as possible isomer Cl−O−ClO2, chlorine (I,V) oxide
- dichlorine trioxide, Cl2O3 as hypothetical isomer O−Cl−O−Cl−O, chlorine (III) oxide
- dichlorine tetroxide, also known as chlorine perchlorate, Cl2O4 or ClOClO3, chlorine (I,VII) oxide
- dichlorine pentoxide, Cl2O5 or ClOOClO3, is hypothetical
- dichlorine hexoxide or chloryl perchlorate, Cl2O6 or [ClO2]+[ClO4]−, chlorine (V,VII) oxide
- dichlorine heptoxide, Cl2O7, chlorine (VII) oxide
- dichlorine octoxide, chlorine (VII) oxide peroxide or dimer of chlorine tetroxide radical, Cl2O8 or (OClO3)2
Several ions are also chlorine oxides: