Production of singlet oxygen by the reaction of non-basic hydrogen peroxide with chlorine gas

Abstract

Non-basic hydrogen peroxide was found to be very easy to react with Cl₂ to produce singlet oxygen O₂(a¹Δ_g) (i.e. the molecular oxygen in its first electronic excited state) when an H⁺ absorbent such as C₅H₅N, CH₃COONH₄, HCOONH₄ or NH₄F was added into H₂O₂ aqueous solution, and the long concealed fact that molecular H₂O₂ can react with Cl₂ to produce O₂(a¹Δ_g) was then uncovered. It is only when an H⁺ absorbent has provided a stronger base than H₂O to absorb the H⁺ produced during the reaction that O₂(a¹Δ_g) can be produced.