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
  • chloryl chloride, ClO2Cl, chlorine (0,IV) oxide
  • chlorine chlorite, ClOClO, chlorine (I,III) oxide
• 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:

• chloryl, ClO+2
• perchloryl, ClO+3
• hypochlorite, ClO−
• chlorite, ClO−2
• chlorate, ClO−3
• perchlorate, ClO−4