Many organic molecules are chiral, which means that they are non-superimposable on their mirror image. Those mirror images are called enantiomers and can have different properties when interacting with other chiral entities, for example, biomolecules. Selectively producing the right enantiomer is therefore important in, for example, pharmaceuticals. University of Groningen chemists Ruth Dorel and Ben Feringa have now devised a method that not only achieves this but that also controls which version is being produced using light. The results were published online by the journal Angewandte Chemie on November 17.