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Updated: Jul 17, 2025
Scanning-probe Single-electron Capacitance Spectroscopy
Published on: July 30, 2013
Metal Site-Specific Electrostatic Field Effects on a Tricopper(I) Cluster Probed by Resonant Diffraction Anomalous
Pinar Alayoglu1, Tieyan Chang2, M Victoria Lorenzo Ocampo3
1Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor St., Chicago, Illinois 60607, United States.
Abstract:
Studies of multinuclear metal complexes are greatly enhanced by resonant diffraction measurements, which probe X-ray absorption profiles of crystallographically independent metal sites within a cluster. In particular, X-ray diffraction anomalous fine structure (DAFS) analysis provides data that can be interpreted akin to site-specific XANES, allowing for differences in metal K-edge resonances to be deconvoluted even for different metal sites within a homometallic system. Despite the prevalence of Cu-containing clusters in biology and energy science, DAFS has yet to be used to analyze multicopper complexes of any type until now. Here, we report an evaluation of trends using a series of strategically chosen Cu(I) and Cu(II) complexes to determine how energy dependencies of anomalous scattering factors are impacted by coordination geometry, ligand shell, cluster nuclearity, and oxidation state. This calibration data is used to analyze a formally tricopper(I) complex that was found by DAFS to be site-differentiated due to the unsymmetrical influence on different Cu sites of the electrostatic field from a proximal K+ cation.
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