Laser light determines chirality of molecules

Laser light determines chirality of molecules

“In pharmaceutics, being able to transition a molecule from one chirality to the other using light instead of wet chemistry would be a dream," says the senior author. The formation of the right- or left-handed version depends on the direction from which laser light hits the initiator.

For the experiment, researchers used the planar formic acid molecule. They activated it with an intense, circularly polarized laser pulse to transition it to a chiral form. At the same time, the radiation caused the molecule to break into its atomic components. It was necessary to destroy the molecule for the experiment so that it could be determined whether a duplicate or mirror version was created.

The authors used the "reaction microscope" (COLTRIMS method) that allows the investigation of individual molecules in a molecular beam. After the molecule's explosive breakdown, the data provided by the detector can be used to precisely calculate the direction and speed of the fragments' paths. This makes it possible to reconstruct the molecule's spatial structure.

In order to create chiral molecules with the desired chirality in the future, it has to be ensured that the molecules are oriented the same way with regard to the circularly polarized laser pulse. This could be achieved by orienting them beforehand using a long-wave laser light.

This discovery could also play a critical role in generating larger quantities of molecules with uniform chirality. However, the researchers believe that in such cases, liquids would probably be radiated rather than gases. "There is a lot of work to be done before we get that far," the author believes.