title: Molecular-shape-dependent photophysical properties of meso-β doubly linked Zn(II) porphyrin arrays and their indene-fused analogues.
abstract: meso-β doubly linked Zn(II) porphyrin arrays and their indene-fused analogues were prepared by Suzuki-Miyaura coupling and subsequent oxidation with DDQ-Sc(OTf)(3). The excited state properties of these conjugated porphyrin arrays have been investigated by steady-state and time-resolved spectroscopy along with quantum mechanical calculations to reveal their molecular shape dependencies with respect to syn- versus anti-connectivity as well as nonfused versus fused structures. Nonfused syn-trimer exhibits nearly the same S(1)-state lifetime and two-photon absorption (TPA) value as the nonfused dimer, while the nonfused anti-trimer exhibits different values. The TD-DFT calculations also demonstrate that the nonfused anti-trimer has a different electronic structure from the corresponding syn-trimer. Indene-fused dimers and trimers exhibit the enhanced TPA values and shortened S(1)-state lifetime because of the elongated π-conjugation and the perturbation of electronic structures. Our research provides further insight into the molecular-shape-dependent electronic properties of meso-β doubly linked Zn(II) porphyrin arrays.
authors.affiliation: Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul 120-749, Korea.
authors.forename: Ji Haeng
authors.initials: JH
authors.lastname: Heo
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Ikeda
authors.forename: Jong Min
authors.initials: JM
authors.lastname: Lim
authors.forename: Naoki
authors.initials: N
authors.lastname: Aratani
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Osuka
authors.forename: Dongho
authors.initials: D
authors.lastname: Kim