2017 May 17 - June 29
2017 October 11 - December 21
2017 Proposal deadline: 08/01/17
2017 BTR deadline: 09/10/17
A new CHESS user group, attending our 1st XES User Meeting workshop in June 2015, has published results from data collected during that visit! Feifei Li1, Erik Farquhar2, and co-workers published, “Cobalt Kβ Valence-to-Core X-ray Emission Spectroscopy: A Study of Low-Spin Octahedral Cobalt(III) Complexes” in Dalton Transactions 45, 14191-14202 (2016).
They used the CHESS designed Dual-Array Valence Emission Spectrometer (DAVES) to collect cobalt Kβeta V2C (valence-to-core) emission spectra from low-spin cobalt complexes with different ligand donors, and compared their measurements with DFT calculations. The spectra demonstrate sensitivity to cobalt-ligand coordination environment and provide a firm basis for using this hard x-ray spectroscopy to study the physical and electronic structures of a wide range of cobalt coordination centers in (bio)catalysts and for other applications. The figure shows the observed correlation between V2C emission peak area and octahedral crystal field splitting parameter Δoct (determined from DFT-calculation) across the ligand spectrochemical series.
1Department of Chemistry & Biochemistry, New Mexico State University, Las Cruces, NM
2CWRU Center for Synchrotron Biosciences, Brookhaven National Laboratory
This work was supported by: New Mexico State University, National Institutes of Health grant P30-EB-009998 (CWRU Center for Synchrotron Biosciences, PI: Mark R. Chance), start-up funds from Harvey Mudd College, Cornell High Energy Synchrotron Source (CHESS) supported by the National Science Foundation and the National Institutes of Health/National Institute of General Medical Sciences under NSF award DMR-1332208, and the Extreme Science and Engineering Discovery Environment (XSEDE) supported by National Science Foundation grant number ACI-1053575.
Submitted by: Ken Finkelstein, CHESS, Cornell University