title: Excitation energy migration in a dodecameric porphyrin wheel.
abstract: Intramolecular excitation energy hopping (EEH) time within a dodecameric porphyrin wheel C6ZA, in which six meso-meso linked zinc(II) diporphyrin (Z2) subunits are bridged by 1,3-phenylene spacers, is deduced by a Förster energy hopping model based on S(1)-S(1) exciton-exciton annihilation and anisotropy depolarization. Under the assumption that the energy hopping sites are six Z2 subunits, two different observables (e.g., exciton-exciton annihilation and anisotropy depolarization times) consistently give the EEH time of 4.0 +/- 0.4 ps via 1,3-phenylene spacer of C6ZA, which is faster than 9.4 ps of linear 2Z2 (1,3-phenylene-linked zinc(II) tetraporphyrin). As a consequence, C6ZA serves as a well-defined two-dimensional model for a light-harvesting complex.
authors.affiliation: Center for Ultrafast Optical Characteristics Control and Department of Chemistry, Yonsei University, Seoul 120-749, Korea.
authors.forename: In-Wook
authors.initials: IW
authors.lastname: Hwang
authors.forename: Dah Mee
authors.initials: DM
authors.lastname: Ko
authors.forename: Tae Kyu
authors.initials: TK
authors.lastname: Ahn
authors.forename: Zin Seok
authors.initials: ZS
authors.lastname: Yoon
authors.forename: Dongho
authors.initials: D
authors.lastname: Kim
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Peng
authors.forename: Naoki
authors.initials: N
authors.lastname: Aratani
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Osuka