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

• Oxygen fluoride(s), bromine oxide(s), iodine oxide(s) – analogous oxygen halide and halogen oxides
• Sulfur fluoride(s), sulfur chloride(s), sulfur bromide(s), sulfur iodide(s) – analogous sulfur halides, some of which are valence isoelectronic with chlorine oxides.

• Chlorine oxoacids and structure of dichlorine oxides. Chem. Educator, Vol. 16, 2011, vol. 16, pp. 275—278