Chlorine and oxygen can bond in a number of ways:
chlorine monoxide radical, ClO•, chlorine (II) oxide radical chloroperoxyl radical, ClO2•, 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
See also 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.
References Chlorine oxoacids and structure of dichlorine oxides. Chem. Educator, Vol. 16, 2011, vol. 16, pp. 275—278