X-rays make molecular movie

Researchers have made a film of a molecule's structural changes during a chemical reaction.

A team led by Michael Minitti at the SLAC National Accelerator Laboratory in Menlo Park, California, used a powerful free-electron laser to fire ultrafast X-ray pulses at the ring structure of 1,3-cyclohexadiene as it opened up to form the linear molecule 1,3,5-hexatriene. The scattered X-rays provided structural snapshots roughly every 80 femtoseconds during the 200-femtosecond reaction (1 femtosecond is 10⁻¹⁵ seconds). Using these results and theoretical calculations, the team worked out the most likely path for the reaction.

The technique could reveal new reaction mechanisms, the authors say.

Phys. Rev. Lett. http://dx.doi.org/10.1103/physrevlett.114.255501 (2015)