During the project the MechaniChiral team achieved the following key scientific breakthroughs:
1) New, general scalable methods to make mechanically chiral rotaxanes
We have developed new chemical techniques that allow us to make new types of mechanically chiral molecules, including mechanically planar chiral, mechanically axially chiral and mechanical geometric isomers. These methods have opened up the structures whose properties and applications can be investigated. These methods are exceptionally flexible, in one case, allowing 11 new mechanically chiral molecules to be made using simple starting materials. Although we focused primarily on synthetic routes using the active template approach, towards the end of the project we also observed stereoselectivity in other systems that we will exploit in future.
2) Mechanically chiral sensors
We have developed mechanically chiral rotaxanes that interact with other small molecules to provide information about the purity of samples and their properties. Having demonstrated this principle we are now developing practical examples that can be used in the development of new chemical reactions and the analysis of medically relevant samples.
3) Mechanically chiral catalysts
We have demonstrated the first examples of catalysts based on mechanically chiral molecules. With prototypes in hand, we are now investigating the benefits of this new approach to catalyst development. We also discovered new ways of controlling catalyst activity using the mechanical bond, which open new paths for exploiting catenanes and rotaxanes in future.
4) Unexpected findings
During our work on MechaniChiral, we also discovered new types of stereochemistry and clarified long-held misconceptions, both of which place the field of mechanostereochemistry on a firmer theoretical footing. We also re-discovered some key effects of the mechanical bond on coordination chemistry, which we are now exploiting in the development of single ion magnets and ligands for medical imaging.
We are exploiting our results in various ways, from extending our studies on catalysis and sensing towards practically useful systems, to developing new types of prodrugs and imaging agents in collaboration with new project partners.
Our results have been widely disseminated through scientific publications (28 to date with several more in preparation/under consideration), including key review articles that provide a detailed explanation of our stereochemical findings and analysis. Prof Goldup and his team have delivered lectures all over the world at scientific meetings and university colloquia describing the findings of the project, including public, keynote and award lectures.
