title: pH-induced interconversion between J-aggregates and H-aggregates of 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin in polyelectrolyte multilayer films.
abstract: We fabricated a layer-by-layer (LbL) film composed of 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (TPPS) and poly(allylamine) (PAA) and investigated its pH response by UV-visible spectrometry. When the (PAA/TPPS)5PAA film was immersed in a pH 1.5 solution, J-aggregate bands were observed at 484 and 691 nm. Above pH 3.0, the J-aggregates were completely dissociated and an H-aggregate band was observed at 405 nm. The interconversion between the J-aggregates and H-aggregates in the LbL film was repeatable and controllable by changing the pH of the solutions.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Tohoku University, Aramaki, Aoba, Sendai 980-8578, Japan. egawa@neutron.pharm.tohoku.ac.jp
authors.forename: Yuya
authors.initials: Y
authors.lastname: Egawa
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Hayashida
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Anzai
mesh_terms: D004573:Electrolytes / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D011166:Porphyrins / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
chemical_list: D004573:Electrolytes; D011166:Porphyrins; C509598:tetra(4-sulfonatophenyl)porphyrin