# Self‐Assembly of Cholane–Phenanthrene–Cholane Trimers for Light‐Harvesting Supramolecular Systems

## TL;DR

Researchers created light-harvesting nanostructures using cholesterol-based molecules, showing how their shape and efficiency depend on assembly conditions and additives.

## Contribution

A new method for forming light-harvesting supramolecular systems using isomeric cholane–phenanthrene–cholane trimers.

## Key findings

- Nanostructure morphology depends on phenanthrene isomer and cooling rate during assembly.
- Doping with pyrene increases quantum yield fivefold, showing potential for artificial light-harvesting.
- 2D nanosheets and 3D worm-like or tubular structures are formed under different conditions.

## Abstract

The self‐assembly of two isomeric amphiphilic cholane–phenanthrene–cholane trimers and the light‐harvesting properties of the formed supramolecular assemblies in aqueous medium are presented. Distinct differences in the supramolecular nanostructures are observed based on the type of phenanthrene isomer used, as well as on the cooling rate applied during the thermal self‐assembly process. A fast cooling rate results in the formation of 2D objects (nanosheets) with both trimers. In contrast, a slow cooling process results in the observation of 3D objects, with worm‐like nanostructures for the self‐assembled 3,6‐disubstituted phenanthrene trimer and nanotubes for the 2,7‐isomer. Upon doping with an acceptor chromophore, the supramolecular phenanthrene assemblies demonstrate efficient energy transfer. The presence of small quantities (6%) of a pyrene acceptor results in a fivefold increase in the quantum yield compared to the phenanthrene trimer alone, highlighting their potential as artificial light‐harvesting complexes. This work underscores the versatility of amphiphilic phenanthrene derivatives as building blocks for light‐harvesting supramolecular systems.

The self‐assembly of phosphodiester‐linked cholane–phenanthrene–cholane trimers is described. The morphology of the formed nanostructures depends on the phenanthrene isomer used and on the cooling rate during the assembly process leading to nanosheets, worm‐like structures, or nanotubes. Doping with pyrene results in a strong increase in the quantum yield, demonstrating the potential of these assemblies as artificial light‐harvesting systems.© 2025 WILEY‐VCH GmbH