title: A panchromatic supramolecular fullerene-based donor-acceptor assembly derived from a peripherally substituted bodipy-zinc phthalocyanine dyad.
abstract: A panchromatic 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene-zinc phthalocyanine conjugate (Bodipy-ZnPc) 1 was synthesized starting from phthalocyanine aldehyde 4, via dipyrromethane 3 and dipyrromethene 2. Conjugate 1 represents the first example in which a Bodipy unit is tethered to the peripheral position of a phthalocyanine core. Electrochemical and optical measurements provided evidence for strong electronic interactions between the Bodipy and ZnPc constituents in the ground state of 1. When conjugate 1 is subjected to photoexcitation in the spectral region corresponding to the Bodipy absorption, the strong fluorescence characteristic of the latter subunit is effectively quenched (i.e., > or = 97%). Excitation spectral analysis confirmed that the photoexcited Bodipy and the tethered ZnPc subunits interact and that intraconjugate singlet energy transfer occurs with an efficiency of ca. 25%. Treatment of conjugate 1 with N-pyridylfulleropyrrolidine (8), an electron-acceptor system containing a nitrogen ligand, gives rise to the novel electron donor-acceptor hybrid 1<-->8 through ligation to the ZnPc center. Irradiation of the resulting supramolecular ensemble within the visible range leads to a charge-separated Bodipy-ZnPc(*+)-C(60)(*-) radical-ion-pair state, through a sequence of excited-state and charge transfers, characterized by a remarkably long lifetime of 39.9 ns in toluene.
authors.affiliation: Departamento de Quimica Organica, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
authors.forename: Yannick
authors.initials: Y
authors.lastname: Rio
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Seitz
authors.forename: Andreas
authors.initials: A
authors.lastname: Gouloumis
authors.forename: Purificacion
authors.initials: P
authors.lastname: Vázquez
authors.forename: Jonathan L
authors.initials: JL
authors.lastname: Sessler
authors.forename: Dirk M
authors.initials: DM
authors.lastname: Guldi
authors.forename: Tomás
authors.initials: T
authors.lastname: Torres
mesh_terms: D001896:Boron Compounds / Q000737:chemistry*; D019281:Dimerization; D004563:Electrochemistry / Q000379:methods; D005453:Fluorescence; D037741:Fullerenes / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry*; D054833:Isoindoles; D008956:Models, Chemical; D009942:Organometallic Compounds / Q000737:chemistry*; D010777:Photochemistry / Q000379:methods; D011162:Porphobilinogen / Q000031:analogs & derivatives / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D017967:Zinc Compounds
chemical_list: C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D001896:Boron Compounds; D037741:Fullerenes; D007211:Indoles; D054833:Isoindoles; D009942:Organometallic Compounds; D017967:Zinc Compounds; C507544:dipyrromethene; C052159:Zn(II)-phthalocyanine; D011162:Porphobilinogen; C013647:phthalocyanine