title: Amphiphilic homopolymer as a reaction medium in water: product selectivity within polymeric nanopockets.
abstract: A styrene-based water-soluble polymer has been explored for its use as a host for lipophilic substrates in aqueous medium. Unimolecular reactions, namely, photo-Fries rearrangement of naphthyl esters, alpha-cleavage reaction of 1-phenyl-3-p-tolyl-propan-2-one, and Norrish type I and type II reactions of benzoin alkyl ethers were examined. We find that the hydrophobic domains generated by the polymer not only restrict the mobility of the radicals but also modestly incarcerate the substrate, intermediates, and products during the time scale of the reactions. Comparative studies of the same photoreactions in micelles formed from small molecule surfactants and an amphiphilic diblock copolymer demonstrate that the styrene-based water-soluble polymer aggregates in aqueous medium offer better selectivity.
authors.affiliation: Department of Chemistry, University of Miami, Coral Gables, Florida 33124, USA.
authors.forename: Selvanathan
authors.initials: S
authors.lastname: Arumugam
authors.forename: Dharma Rao
authors.initials: DR
authors.lastname: Vutukuri
authors.forename: S
authors.initials: S
authors.lastname: Thayumanavan
authors.forename: V
authors.initials: V
authors.lastname: Ramamurthy
mesh_terms: D004952:Esters / Q000138:chemical synthesis / Q000737:chemistry / Q000528:radiation effects; D005609:Free Radicals / Q000737:chemistry; D008027:Light; D008823:Micelles; D008970:Molecular Weight; D049329:Nanostructures / Q000737:chemistry*; D010782:Photolysis; D011137:Polystyrenes / Q000737:chemistry* / Q000528:radiation effects; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D004952:Esters; D005609:Free Radicals; D008823:Micelles; D011137:Polystyrenes; D014867:Water