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April 2017

Coming to a Lab Bench Near You: Femtosecond X-Ray Spectroscopy


The ephemeral electron movements in a transient state of a reaction important in biochemical and optoelectronic processes have been captured and, for the first time, directly characterized using ultrafast X-ray spectroscopy by staff and users of the Molecular Foundry.

Like many rearrangements of molecular structures, the ring-opening reactions in this study occur on timescales of hundreds of femtoseconds (1 femtosecond equals a millionth of a billionth of a second). This light-activated, ring-opening reaction of cyclic molecules is a ubiquitous chemical process that is a key step in the photobiological synthesis of vitamin D in the skin and in optoelectronic technologies underlying optical switching, optical data storage, and photochromic devices.

The researchers were able to collect snapshots of the electronic structure during the reaction by using femtosecond pulses of X-ray light on a tabletop apparatus and then decoded through a series of theoretical simulations. The simulations modeled both the ring-opening process and the interaction of the X-rays with the molecule during its transformation.

Read the full press release.