Femtosecond X-ray absorption spectroscopy at a hard X-ray free electron laser: application to spin crossover dynamics.
نویسندگان
چکیده
X-ray free electron lasers (XFELs) deliver short (<100 fs) and intense (∼10(12) photons) pulses of hard X-rays, making them excellent sources for time-resolved studies. Here we show that, despite the inherent instabilities of current (SASE based) XFELs, they can be used for measuring high-quality X-ray absorption data and we report femtosecond time-resolved X-ray absorption near-edge spectroscopy (XANES) measurements of a spin-crossover system, iron(II) tris(2,2'-bipyridine) in water. The data indicate that the low-spin to high-spin transition can be modeled by single-exponential kinetics convoluted with the overall time resolution. The resulting time constant is ∼160 fs.
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عنوان ژورنال:
- The journal of physical chemistry. A
دوره 117 4 شماره
صفحات -
تاریخ انتشار 2013