title: Six-Coordinate Zinc Porphyrins for Template-Directed Synthesis of Spiro-Fused Nanorings.
abstract: Five-coordinate geometry is the standard binding mode of zinc porphyrins with pyridine ligands. Here we show that pseudo-octahedral six-coordinate zinc porphyrin complexes can also be formed in solution, by taking advantage of the chelate effect. UV-vis-NIR titrations indicate that the strength of this second coordination is ca. 6-8 kJ mol(-1). We have used the formation of six-coordinate zinc porphyrin complexes to achieve the template-directed synthesis of a 3D π-conjugated spiro-fused array of 11 porphyrin units, covalently connected in a nontrivial topology. Time-resolved fluorescence anisotropy experiments show that electronic excitation delocalizes between the two perpendicular nanorings of this spiro-system within the experimental time-resolution of 270 fs.
authors.affiliation: Chemistry Research Laboratory, Department of Chemistry, University of Oxford , Oxford OX1 3TA, United Kingdom.
authors.forename: Ludovic
authors.initials: L
authors.lastname: Favereau
authors.affiliation: Chemistry Research Laboratory, Department of Chemistry, University of Oxford , Oxford OX1 3TA, United Kingdom.
authors.forename: Arjen
authors.initials: A
authors.lastname: Cnossen
authors.affiliation: Chemistry Research Laboratory, Department of Chemistry, University of Oxford , Oxford OX1 3TA, United Kingdom.
authors.forename: Julien B
authors.initials: JB
authors.lastname: Kelber
authors.affiliation: Clarendon Laboratory, Department of Physics, University of Oxford , Oxford OX1 3PU, United Kingdom.
authors.forename: Juliane Q
authors.initials: JQ
authors.lastname: Gong
authors.affiliation: Chemistry Research Laboratory, Department of Chemistry, University of Oxford , Oxford OX1 3TA, United Kingdom.
authors.forename: René M
authors.initials: RM
authors.lastname: Oetterli
authors.affiliation: Chemistry Research Laboratory, Department of Chemistry, University of Oxford , Oxford OX1 3TA, United Kingdom.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Cremers
authors.affiliation: Clarendon Laboratory, Department of Physics, University of Oxford , Oxford OX1 3PU, United Kingdom.
authors.forename: Laura M
authors.initials: LM
authors.lastname: Herz
authors.affiliation: Chemistry Research Laboratory, Department of Chemistry, University of Oxford , Oxford OX1 3TA, United Kingdom.
authors.forename: Harry L
authors.initials: HL
authors.lastname: Anderson