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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 ?-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.

SUBMITTER: Favereau L

PROVIDER: S-EPMC4686216 | biostudies-literature | 2015 Nov

REPOSITORIES: biostudies-literature

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Six-Coordinate Zinc Porphyrins for Template-Directed Synthesis of Spiro-Fused Nanorings.

Favereau Ludovic L Cnossen Arjen A Kelber Julien B JB Gong Juliane Q JQ Oetterli René M RM Cremers Jonathan J Herz Laura M LM Anderson Harry L HL

Journal of the American Chemical Society 20151106 45

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 o ...[more]

PMID: 26536147

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