Chemists at TU Dortmund University Solve Molecular Puzzle

When examining biological structures on atomic scale, the complexity of their shapes and functions, which form the basis of all life on Earth, is fascinating. While nature has developed intricate networks of interacting molecular structures over billions of years, synthetic chemists still face major challenges when synthesizing complex molecules. One approach is multi-step organic synthesis, which requires laborious and resource-intensive laboratory work, often over many years.

Another strategy is called “self-assembly” and is based on bringing together a set of simple building blocks that form a larger object by binding to each other via weak and dynamic interactions. This allows fundamental geometric factors to control the outcome of the structure-forming process until all components hitting each other by chance then form a stable product. In this process, incorrectly assembled, unstable parts fall apart again and contribute to forming the stable end product until all the building blocks are used up. In the past, this procedure, comparable to a puzzle that solves itself, often suffered from the limited number of different building blocks that could be integrated in the final product. Previous attempts to incorporate a greater variety and number of components in order to produce lower symmetric assemblies that come closer to biological structures in terms of their shapes and functions often resulted in the formation of statistical mixtures of various self-assembled objects. In other words, the building blocks were unable to decide which product to form, and the molecular puzzle did not produce a single defined solution.

Controlled interaction of organic building blocks with metals

This is the starting point for the research conducted by Professor Guido Clever’s group: Within the RAMSES research project, which is funded by the European Research Council (ERC), the team has developed several strategies to overcome this limitation and control the interaction of distinguishable building blocks. This increases the structural and functional complexity of these molecular puzzles and brings them closer to application. The group had previously produced a number of complex nanostructures by turning self-assembly into self-sorting. The resulting nanostructures can serve as specific receptors for biomolecules, tunable optical tools and new emulsifiers for organic solvents. Initially, however, the functions of these systems were based on the interaction between just two chemically different building blocks.