title: Design and photophysical properties of zinc(II) porphyrin-containing dendrons linked to a central artificial special pair.
abstract: The click chemistry synthesis and photophysical properties, notably photo-induced energy and electron transfers between the central core and the peripheral chromophores of a series of artificial special pair-dendron systems (dendron = G1, G2, G3; Gx = zinc(II) tetra-meso-arylporphyrin-containing polyimides) built upon a central core of dimethylxanthenebis(metal(II) porphyrin) (metal = zinc, copper), are reported. The dendrons act as singlet and triplet energy acceptors or donors, depending on the dendrimeric systems. The presence of the paramagnetic d(9) copper(II) in the dendrimers promotes singlet-triplet energy transfer from the zinc(II) tetra-meso-arylporphyrin to the bis(copper(II) porphyrin) unit and slow triplet-triplet energy transfer from the central bis(copper(II) porphyrin) fragment to the peripheral zinc(II) tetra-meso-arylporphyrin. If bis(zinc(II) porphyrin) is the central core, evidence for chain folding is observed; this is unambiguously demonstrated by the presence of triplet-triplet energy transfer in the heterobimetallic systems, a process that can only occur at short distances.
authors.affiliation: Université de Bourgogne, ICMUB (UMR 5260), 9 Avenue Alain Savary, BP 47870, 21078 Dijon Cedex, France.
authors.forename: Frédérique
authors.initials: F
authors.lastname: Brégier
authors.forename: Shawkat M
authors.initials: SM
authors.lastname: Aly
authors.forename: Claude P
authors.initials: CP
authors.lastname: Gros
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Barbe
authors.forename: Yoann
authors.initials: Y
authors.lastname: Rousselin
authors.forename: Pierre D
authors.initials: PD
authors.lastname: Harvey
mesh_terms: D057930:Click Chemistry / Q000379:methods; D003300:Copper / Q000737:chemistry; D050091:Dendrimers / Q000737:chemistry*; D004735:Energy Transfer; D008665:Metalloporphyrins / Q000737:chemistry*; D015394:Molecular Structure; D015032:Zinc / Q000737:chemistry*
chemical_list: D050091:Dendrimers; D008665:Metalloporphyrins; D003300:Copper; D015032:Zinc