Temporal mapping of photochemical reactions and molecular excited states with carbon specificity

Muons help us see the light

29 May 2017

Sunlight-capturing molecules such as chlorophyll underpin almost all life on Earth, yet the light-trapping step is so rapid it is not fully understood. Sichuan University scientists have helped develop a technique to probe, with single-atom sensitivity, the microseconds after a photosensitive molecule absorbs light.

The researchers bathed a light-sensitive organic molecule called TIPS-Pn in laser light and then bombarded it with positively charged subatomic particles called muons. Under these conditions, rather than behave as subatomic particles, the muons acted like pseudo-hydrogen atoms and chemically reacted with TIPS-Pn. The team used a specialized spectroscopy technique to track, atom by atom, TIPS-Pn’s reactivity toward muons over time, and thereby tracked the evolution of its light-excited state.

It’s not just our understanding of the natural world this technique may enlighten. Solar cells, low energy lightbulbs, and even the industrial photocatalysts used to make certain pharmaceuticals, could all be studied under its glow.

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References

1. Nature Materials 16, 467–473 (2017). doi: 10.1038/NMAT4816