Abstract: Methylene blue sensitized photooxidation of phenothiazine (PTH) in sodium dodecylsulphate, cetyl trimethylammonium bromide and brij-35 in methanol-water, ethanol- water and acetonitrile-water gives phenothiazine-3-one (PTN) and phenothiazine sulphoxide as the products at low conversion. A small shift in the λmax indicates the formation of an additional product, which is destroyed during the separation. An inverse ...