Photoinduced Generation of Sulfonic Acid from N-Sulfonyl-Arysulfonamide.

A new method of photochemical generation of sulfonic acid is described. N-sulfonyl-arylsulfonamide which is synthesized easily from arylsulfonamide and sulfony chloride produce sulfonic acids on photoexcitation. Quantum yields of their decomposition are between 0.2 to 0.5, depending on their substituents. A typical example is N-(4-methoxyphenysulfony)-N-methyl-4-methoxyphenysulfonamide which shows quantum yield of 0.5. It is almost the same value as commonly used photo-sulfonic acid generating compounds. Photodecompositon products were characterized by HLPC and Mass spectroscopy, and photodecompositon mechanism is proposed.