Photolytic and radiolytic studies of SO4•− in neat organic solvents

Abstract

A study of SO₄^•− in neat organic solvents by laser photolytic and pulse radiolytic methods has been described for the first time. The sulfate radical was produced in neat CH₃CN and CHCl₃ by laser photolysis of (CTA)₂S₂O₈ (CTA = cetyltrimethylammonium), or in CH₃CN ia reduction of (CTA)₂S₂O₈ with a reducing species produced from pulse radiolysis. The quantum yield of SO₄^•− in CH₃CN was 30% higher than in water, based on our experimental results. The SO₄^•− reacts slowly with CH₃CN, but rapidly with CHCl₃ to form ^•CCl₃ which is further converted into CCl₃O₂^• in the presence of oxygen. Rate constants for hydrogen abstraction from alkanols by SO₄^•− were lower by 1–2 orders of magnitude in CH₃CN than in aqueous solutions.