Electron-Beam-Induced Fries Rearrangement and Oxidation Reactions of Sulfonic Acid Esters in Crystalline State

Radiation‐Induced Reaction of Sulfonamide‐Containing Polymers in the Film State for Color Imaging

“…The shoulder peak around 350 nm in the UV spectrum increased with increases of irradiation doses. We previously reported that 2‐(phenylsulfonyl)aniline was the EB‐induced Fries rearrangement product of benzenesulfonanilide, which is the repeating unit of PSA 21–23. Since the Fries rearrangement product 2‐(phenylsulfonyl)aniline also has a UV absorption at 340 nm, the UV spectral change should result from EB‐induced Fries rearrangement of the sulfonamide moiety of PSA to give the (phenylsulfonyl)aniline structure in the film state.…”

“…Subsequently, the upper excited state of sulfonamides produced by EB irradiation is expected to relax to the lowest excited state, which is the same state as that of photoreaction, resulting in the homolytic cleavage of the SN bond. The obtained radicals should abstract hydrogen radicals from the polymer matrix or absorbed water in the film, yielding aniline and sulfonic acid derivatives 17–23, 27–29. Another route for obtaining the radicals is Fries rearrangement which yields an aminophenylsulfone derivative in the main chain of the polymers.…”

“…This is probably because, in contrast to sulfonic acid derivatives, the corresponding carboxylic acid derivatives undergo Fries rearrangement by photolysis but not by radiolysis under the same conditions. This difference likely results from the fact that the carboxylic acid derivatives in upper excited states cannot relax to the lowest excited state, from which the photo‐Fries rearrangement proceeds; as a result, it must relax to the ground state via other thermal processes 21–23…”

“…Recently, we examined the EB‐induced reactions of photosensitive compounds such as cinnamic acid derivatives,17 sulfonium salts18–20 and sulfonic acid derivatives21–23 in the crystalline state, and also compared those with the corresponding photoreactions. Among these compounds, the EB irradiation of sulfonic acid derivatives in the crystalline state underwent the Fries rearrangement to yield aniline or phenol derivatives, whereas the corresponding carboxylic acid derivatives did not undergo any rearrangement, even though both sulfonic and carboxylic acid derivatives undergo photo‐Fries rearrangement 21–23. EB‐induced Fries rearrangement and scission in the sulfonamide compounds yielded the aniline derivatives; this rearrangement was accompanied by transformation from acidic sulfonamides to basic anilines, as shown in Scheme .…”

Spatial arrangement of block copolymer nanopatterns using a photoactive homopolymer substrate

“…43,44 A number of years ago the JAERI group demonstrated that the Fries rearrangement in sulfonic acid esters and amides can be initiated by electron beam irradiation. 45,46 It may not be unexpected that the Fries rearrangement plays a role in the high energy radiation chemistry of aryl esters since the photochemical Fries rearrangement proceeds via the excited singlet state resulting in homolytic scission of the O-CO bond. 47 High energy irradiation is expected to result in cleavage of this bond as a major reaction pathway, although the energy of the photons and secondary electrons, and hence the product distribution may differ considerably from the photochemical process.…”