Improving sensitivity of XANES structural fit to the bridged metal-metal coordination.

Autor:	Abrosimov SV; The Smart Materials Research Institute, Southern Federal University, Sladkova 178/24, 344090 Rostov-on-Don, Russian Federation., Protsenko BO; The Smart Materials Research Institute, Southern Federal University, Sladkova 178/24, 344090 Rostov-on-Don, Russian Federation., Mannaa AS; The Smart Materials Research Institute, Southern Federal University, Sladkova 178/24, 344090 Rostov-on-Don, Russian Federation., Vlasenko VG; Institute of Physics, Southern Federal University, Stachki Ave 194, 344090 Rostov-on-Don, Russian Federation., Guda SA; The Smart Materials Research Institute, Southern Federal University, Sladkova 178/24, 344090 Rostov-on-Don, Russian Federation., Pankin IA; The Smart Materials Research Institute, Southern Federal University, Sladkova 178/24, 344090 Rostov-on-Don, Russian Federation., Burlov AS; Institute of Physical and Organic Chemistry, Stachki Ave 194/2, 344090 Rostov-on-Don, Russian Federation., Koshchienko YV; Institute of Physical and Organic Chemistry, Stachki Ave 194/2, 344090 Rostov-on-Don, Russian Federation., Guda AA; The Smart Materials Research Institute, Southern Federal University, Sladkova 178/24, 344090 Rostov-on-Don, Russian Federation., Soldatov AV; The Smart Materials Research Institute, Southern Federal University, Sladkova 178/24, 344090 Rostov-on-Don, Russian Federation.
Jazyk:	angličtina
Zdroj:	Journal of synchrotron radiation [J Synchrotron Radiat] 2024 May 01; Vol. 31 (Pt 3), pp. 447-455. Date of Electronic Publication: 2024 Mar 26.
DOI:	10.1107/S1600577524002091
Abstrakt:	Hard X-ray absorption spectroscopy is a valuable in situ probe for non-destructive diagnostics of metal sites. The low-energy interval of a spectrum (XANES) contains information about the metal oxidation state, ligand type, symmetry and distances in the first coordination shell but shows almost no dependency on the bridged metal-metal bond length. The higher-energy interval (EXAFS), on the contrary, is more sensitive to the coordination numbers and can decouple the contribution from distances in different coordination shells. Supervised machine-learning methods can combine information from different intervals of a spectrum; however, computational approaches for the near-edge region of the spectrum and higher energies are different. This work aims to keep all benefits of XANES and extend its sensitivity towards the interatomic distances in the first and second coordination shells. Using a binuclear bridged copper complex as a case study and cross-validation analysis as a quantitative tool it is shown that the first 170 eV above the edge are already sufficient to balance the contributions of Cu-O/N scattering and Cu-Cu scattering. As a more general outcome this work highlights the trivial but often overlooked importance of using `longer' energy intervals of XANES for structural refinement and machine-learning predictions. The first 200 eV above the absorption edge still do not require parametrization of Debye-Waller damping and can be calculated within full multiple scattering or finite difference approximations with only moderately increased computational costs. (open access.)
Databáze:	MEDLINE
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