Dichlorine trioxide, Cl₂O₃, is a chlorine oxide

Chlorine oxide

Chlorine and oxygen can bond in many different ways:* chlorine monoxide * chlorine dioxide * chlorine trioxide * dichlorine monoxide * dichlorine dioxide * dichlorine trioxide...

. It is a dark brown solid discovered in 1967 which is explosive even below 0°C.
It is formed by the low temperature photolysis of ClO₂

Chlorine dioxide

Chlorine dioxide is a chemical compound with the formula ClO2. This yellowish-green gas crystallizes as bright orange crystals at −59 °C. As one of several oxides of chlorine, it is a potent and useful oxidizing agent used in water treatment and in bleaching....

 and is formed along with Cl₂O₆

Dichlorine hexoxide

Dichlorine hexoxide is the chemical compound with the formula . This chlorine oxide is the mixed anhydride of chloric and perchloric acids. It is produced by reaction between chlorine dioxide and excess ozone:...

, Cl₂ and O₂. Its structure is believed to be OCl-ClO₂ with possible isomers such as Cl-O-ClO₂. It is the theoretical anhydride of chlorous acid

Chlorous acid

Chlorous acid is an inorganic compound with the formula HClO2. It is a weak acid. Chlorine has oxidation state +3 in this acid. The pure substance is unstable, disproportionating to hypochlorous acid and chloric acid :Although the acid is difficult to obtain in pure substance, the conjugate base,...

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