Ultrafast Energy Transfer in Biomimetic Multistrand Nanorings
摘要:
We report the synthesis of LH2-like supramolecular double- and triple-stranded complexes based upon porphyrin nanorings. Energy transfer from the antenna dimers to the pi-conjugated nanoring occurs on a subpicosecond time scale, rivaling transfer rates in natural light-harvesting systems. The presence of a second nanoring acceptor doubles the transfer rate, providing strong evidence for multidirectional energy funneling. The behavior of these systems is particularly intriguing because the local nature of the interaction may allow energy transfer into states that are, for cyclic nanorings, symmetry-forbidden in the far field. These complexes are versatile synthetic models for natural light-harvesting systems.
Six-Coordinate Zinc Porphyrins for Template-Directed Synthesis of Spiro-Fused Nanorings
作者:Ludovic Favereau、Arjen Cnossen、Julien B. Kelber、Juliane Q. Gong、René M. Oetterli、Jonathan Cremers、Laura M. Herz、Harry L. Anderson
DOI:10.1021/jacs.5b10126
日期:2015.11.18
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