MS20-P07 The Benefits of Kβ Radiation Michael Bodensteiner (X-ray Crystallography, Faculty of Chemistry and Pharmacy, University of Regensburg, Regensburg, Germany) Tobias Mayr (Faculty of Chemistry and Pharmacy, University of Regensburg, Regensburg, Germany)email: michael.bodensteiner@ur.deKβ is much weaker in intensity than Kα and therefore practically not used for single crystal diffraction experiments. Most X-ray labs are equipped with Mo-Kα and Cu-Kα sources, but in some cases an intermediate wavelength would be desirable. Such a compromise can be provided by Cu-Kβ radiation (λ = 1.39 Å). Compared to Cu-Kα (λ = 1.54 Å) the amount of available data is increased by more than 35 per cent and the absorption significantly lowered. This can also be achieved with Mo-Kα (λ = 0.71 Å), but the quantum efficiency of the diffraction is much higher for Cu-Kβ. Another general advantage of Kβ radiation compared to Kα is the absence of α12 splitting at higher diffraction angles. This leads to a relative improvement of the I/σ(I) at higher resolution. Our investigations have shown that in many cases almost identical or even better quality structures could be obtained by using the Cu-Kβ wavelength compared to either Mo-Kα or Cu-Kα. We even encountered some structures that could only be refined properly when Cu-K β  data was applied.[1]

[1] Marquardt, C., Kahoun, T., Stauber, A., Balázs, G., Bodensteiner, M., Timoshkin, A. Y. &

Scheer, M. (2016). Angew. Chem. Int. Ed., 55, 14828–14832.
Keywords: K-beta radiation, wavelength, data quality