Dichlorine hexoxide(Cl2 O6) is the chemical compound with the formula Cl2O6. This chlorine oxide is the mixed anhydride of chloric and perchloric acids. It is produced by reaction between chlorine dioxide and excess ozone: 2 ClO2 + 2 O3 2 ClO3 + 2 O2 Cl2O6 + 2 O2 Solution Dichlorine hexoxide(Cl2 O6) is the chemical compound with the formula Cl2O6. This chlorine oxide is the mixed anhydride of chloric and perchloric acids. It is produced by reaction between chlorine dioxide and excess ozone: 2 ClO2 + 2 O3 2 ClO3 + 2 O2 Cl2O6 + 2 O2.