Bioinspiriertes Molekulardesign von lichtsammelnden Multiporphyrinsystemen

Abstract

Jüngste Fortschritte bei Grundlagenstudien zu Multiporphyrinsystemen geben Aufschluss über die maßgeblichen Strukturparameter für das Molekulardesign von künstlichen Lichtsammelantennen, die die radähnlichen Antennenkomplexe photosynthetischer Purpurbakterien imitieren. “Kovalente” und “nichtkovalente” Ansätze kamen für den Aufbau von künstlichen lichtsammelnden Multiporphyrinsystemen zum Einsatz. Diese lassen sich in die Kategorien ring‐, windmühlen‐, sternförmig und dendritisch einteilen, wobei insbesondere die dendritischen Multiporphyrinsysteme als vielversprechende Kandidaten gelten. Sie verfügen über einen hohen Absorptionsquerschnitt und ermöglichen einen zielgerichteten vektoriellen Energietransfer über große Entfernungen. Erwartet wird, dass sich solche molekularen und supramolekularen Systeme als leistungsstarke Komponenten für die molekulare Elektronik und in photonischen Bauelementen eignen.

The Role of Electronic Coupling in Linear Porphyrin Arrays Probed by Single‐Molecule Fluorescence Spectroscopy

“…Multiporphyrin assemblies have attracted great attention because of their potential application in molecular scale photonic devices such as light-harvesting arrays, [1][2][3] molecular wires, [4][5][6][7][8] photovoltaic cells, [9,10] and nonlinear optics. [11,12] One of the central objectives in the construction of these assemblies has been to achieve relevant electronic couplings ranging from p-conjugation to excitonic dipole coupling, as well as a combination of these two, so as to fulfill the prerequisite properties of the device.…”

Mesoscale Integration in Titania/J‐Aggregate Hybrid Nanofibers

“…[3][4][5] In particular, the programmed assembly of porphyrin molecules can produce quasi one-dimensional nanostructures (J-aggregates) that in part mimic complex supramolecular assemblies found in biology, such as the light harvesting center of green sulfur bacteria. [6,7] The spatial arrangement of molecular transition dipoles in these synthetic analogues facilitates strong coupling of the chromophores to produce higher-ordered nanostructures that could ultimately pave the way for fast excitation energy transfer over hundreds of molecules.…”

“…[3][4][5] In particular, the programmed assembly of porphyrin molecules can produce quasi one-dimensional nanostructures (J-aggregates) that in part mimic complex supramolecular assemblies found in biology, such as the light harvesting center of green sulfur bacteria. [6,7] The spatial arrangement of molecular transition dipoles in these synthetic analogues facilitates strong coupling of the chromophores to produce higher-ordered nanostructures that could ultimately pave the way for fast excitation energy transfer over hundreds of molecules.[7] As a result, porphyrin-based nanostructures have been developed for use in photovoltaic devices, [2][3][4][5] and immobilized within organic/ inorganic thin films or on virus particle surfaces for lightharvesting, energy-transport, photocatalysis, and sensing applications. [8][9][10][11][12][13][14][15][16][17][18] Tetrakis(4-sulfonatophenyl)porphine (TPPS) is a watersoluble porphyrin that spontaneously self-assembles under aqueous acidic conditions to produce a range of supramolecular nanostructures.…”

“…[1][2][3] Amongst a wide variety of possible supramolecular tectons, porphyrins and phthalocyanines are of special interest because of their inherent electronic and optical properties. [3][4][5] In particular, the programmed assembly of porphyrin molecules can produce quasi one-dimensional nanostructures (J-aggregates) that in part mimic complex supramolecular assemblies found in biology, such as the light harvesting center of green sulfur bacteria.…”

Fullerene‐Terminated Dendritic Multiporphyrin Arrays: “Dendrimer Effects” on Photoinduced Charge Separation

“…[2,3] This observation prompted us to integrate such dendritic dye molecules as light-harvesting antennas into electron-transfer relay systems. Here we report the molecular design and photoinduced electron-transfer properties of a series of fullerene-terminated dendritic zinc-porphyrin arrays nP Zn -C 60 (Scheme 1).…”