title: Self-Assembly of Russian Doll Concentric Porphyrin Nanorings.
abstract: Electronic communication between concentric macrocycles with wave functions that extend around their circumferences can lead to remarkable behavior, as illustrated by multiwalled carbon nanotubes and photosynthetic chlorophyll arrays. However, it is difficult to hold one π-conjugated molecular ring inside another. Here, we show that ring-in-ring complexes, consisting of a 6-porphyrin ring locked inside a 12-porphyrin ring, can be assembled by placing different metals in the two rings (zinc and aluminum). A bridging ligand with carboxylate and imidazole binding sites forms spokes between the two rings, resulting in a highly cooperative supramolecular self-assembly process. Excitation is transferred from the inner 6-ring to the outer 12-ring of this Russian doll complex within 40 ps. These complexes lead to a form of template-directed synthesis in which one nanoring promotes formation of a larger concentric homologous ring; here, the effective template is an eight-component noncovalent assembly. Russian doll templating provides a new approach to amplifying the size of a covalent nanostructure.
authors.affiliation: Department of Chemistry, University of Oxford , Chemistry Research Laboratory, Oxford OX1 3TA, United Kingdom.
authors.forename: Sophie A L
authors.initials: SA
authors.lastname: Rousseaux
authors.affiliation: Department of Physics, University of Oxford , Clarendon Laboratory, Oxford OX1 3PU, United Kingdom.
authors.forename: Juliane Q
authors.initials: JQ
authors.lastname: Gong
authors.affiliation: Department of Chemistry, University of Oxford , Chemistry Research Laboratory, Oxford OX1 3TA, United Kingdom.
authors.forename: Renée
authors.initials: R
authors.lastname: Haver
authors.affiliation: Department of Chemistry, University of Oxford , Chemistry Research Laboratory, Oxford OX1 3TA, United Kingdom.
authors.forename: Barbara
authors.initials: B
authors.lastname: Odell
authors.affiliation: Department of Chemistry, University of Oxford , Chemistry Research Laboratory, Oxford OX1 3TA, United Kingdom.
authors.forename: Tim D W
authors.initials: TD
authors.lastname: Claridge
authors.affiliation: Department of Physics, University of Oxford , Clarendon Laboratory, Oxford OX1 3PU, United Kingdom.
authors.forename: Laura M
authors.initials: LM
authors.lastname: Herz
authors.affiliation: Department of Chemistry, University of Oxford , Chemistry Research Laboratory, Oxford OX1 3TA, United Kingdom.
authors.forename: Harry L
authors.initials: HL
authors.lastname: Anderson