title: Substituent effects of porphyrins on structures and photophysical properties of amphiphilic porphyrin aggregates.
abstract: Substituent effects of porphyrin on the structures and photophysical properties of the J-aggregates of protonated 5-(4-alkoxyphenyl)-10,15,20-tris(4-sulfonatophenyl)porphyrin have been examined for the first time. Selective formation of the porphyrin J-aggregate was attained when suitable length of the alkoxy group was employed for the amphiphilic porphyrin. Namely, a regular leaflike structure was observed for the J-aggregates of protonated 5-(4-octyloxyphenyl)-10,15,20-tris(4-sulfonatophenyl)porphyrin, which was consistent with the results obtained by using the UV-visible absorption and dynamic light-scattering measurements. A bilayer structure in which the hydrophobic alkoxyl groups facing inside the bilayer are interdigitated to each other, whereas the hydrophilic porphyrin moieties are exposed outside, was proposed to explain the unique porphyrin J-aggregate. Fast energy migration and efficient quenching by defect site in the J-aggregates were suggested to rationalize the short lifetimes of the excited J-aggregates.
authors.affiliation: Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Hosomizu
authors.forename: Masaaki
authors.initials: M
authors.lastname: Oodoi
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Umeyama
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Matano
authors.forename: Kaname
authors.initials: K
authors.lastname: Yoshida
authors.forename: Seiji
authors.initials: S
authors.lastname: Isoda
authors.forename: Marja
authors.initials: M
authors.lastname: Isosomppi
authors.forename: Nikolai V
authors.initials: NV
authors.lastname: Tkachenko
authors.forename: Helge
authors.initials: H
authors.lastname: Lemmetyinen
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Imahori
mesh_terms: D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry / Q000379:methods; D046529:Microscopy, Electron, Transmission; D015394:Molecular Structure; D010777:Photochemistry; D011166:Porphyrins / Q000737:chemistry*
chemical_list: D011166:Porphyrins