A Complex Comprising a Cyanine Dye Rotaxane and a Porphyrin Nanoring as a Model Light‐Harvesting System

Abstract

A nanoring‐rotaxane supramolecular assembly with a Cy7 cyanine dye (hexamethylindotricarbocyanine) threaded along the axis of the nanoring was synthesized as a model for the energy transfer between the light‐harvesting complex LH1 and the reaction center in purple bacteria photosynthesis. The complex displays efficient energy transfer from the central cyanine dye to the surrounding zinc porphyrin nanoring. We present a theoretical model that reproduces the absorption spectrum of the nanoring and quantifies the excitonic coupling between the nanoring and the central dye, thereby explaining the efficient energy transfer and demonstrating similarity with structurally related natural light‐harvesting systems.

Photocontrolled Light‐Harvesting Supramolecular Assembly Based on Aggregation‐Induced Excimer Emission

“…[ 11 ] Anderson and co‐workers synthesized a complex comprising a cyanine dye rotaxane and a porphyrin nanoring as a model light‐harvesting system. [ 12 ] Wang and coworkers fabricated highly efficient artificial light‐harvesting systems based on supramolecular self‐assembly. [ 4a,13 ] Our group also developed aqueous light‐harvesting systems with efficient energy transfer efficiency.…”

Macrocyclic Donor–Acceptor Dyads Composed of a Perylene Bisimide Dye Surrounded by Oligothiophene Bridges

“…Cyclic molecular structures have always attracted chemists for av ariety of reasons.T hese include purely aesthetic reasons, [1] the suitability of macrocycles as well pre-organized supramolecular host [2] and the usefulness of p-conjugated (macro-)cycles to shed light on aromaticity [3] or for enabling special physical properties [4] of interest. Emanating from the latter research field, the fascinating classes of cyclo-[n]oligothiophenes, [5] cyclo[n]paraphenylenes, [6] carbon nanobelts [7] as well as porphyrin nanorings [8] have been realized in the recent years.S ome of them, such as Bäuerlesc yclo-[n]oligothiophenes or Osukasa nd Andersonsp orphyrin nanorings,a lso exhibit fascinating properties,t hat is,t he formation of polaron pairs (biradicals) or the switching between aromatic and antiaromatic properties upon oxida-tion or photoexcitation, respectively.…”

Using the Mechanical Bond to Tune the Performance of a Thermally Activated Delayed Fluorescence Emitter**

“…An alternative and as yet unexplored approach is to use the crowded, flexible environment of the mechanical bond in mechanically interlocked molecules (MIMs) [16] such ar otaxanes to influence the properties of aT ADF luminophore, although this approach has been used to influence the properties of other radiative processes. [17] Indeed, the investigation of MIMs has expanded dramatically over the last half-century,t hanks largely to the development of high yielding,f lexible synthetic methodologies [16] that make them available for study in ar ange of areas including as sensors [18] and catalysts, [19] as well as their well-known role as components of molecular machines. [20] Herein we report as eries of carbazole-benzophenone-basedr otaxanes that demonstrate the ability of the environment provided by the macrocycles threaded close to the emitting core to fine-tune the photophysical properties of aTADF-active axle in solution and thin films.…”