Probing the Anisotropic Distortion of Photoexcited Spin Crossover Complexes with Picosecond X-ray Absorption Spectroscopy

Summary, in English

For numerous spin crossover complexes, the anisotropic distortion of the first coordination shell around the transition metal center governs the dynamics of the high-spin/low-spin interconversion. However, this structural parameter remains elusive for samples that cannot be investigated with crystallography. The present work demonstrates how picosecond X-ray absorption spectroscopy is able to capture this specific deformation in the photoinduced high-spin state of solvated [Fe(terpy)(2)](2+), a complex which belongs to the prominent family of spin crossover building blocks with nonequivalent metal-ligand bonds. The correlated changes in Fe-N-Axial, Fe-N-Distal, and bite angle N-Distal-Fe-N-Axial extracted from the measurements are in very good agreement with those predicted by DFT calculations in D-2d symmetry. The outlined methodology is generally applicable to the characterization of ultrafast nuclear rearrangements around metal centers in photoactive molecular complexes and nanomaterials, including those that do not display long-range order.

• Author: Sophie Canton; Xiaoyi Zhang; Latevi M. Lawson Daku; Amanda L. Smeigh; Jianxin Zhang; Yizhu Liu; Carl-Johan Wallentin; Klaus Attenkofer; Guy Jennings; Charles A. Kurtz; David Gosztola; Kenneth Wärnmark; Andreas Hauser; Villy Sundström
• Department/s: Chemical Physics; Department of Chemistry; Centre for Analysis and Synthesis
• Publishing year: 2014
• Language: English
• Pages: 4536-4545
• Publication/Series: Journal of Physical Chemistry C
• Volume: 118
• Issue: 8
• Links: http://dx.doi.org/10.1021/jp5003963
• Document type: Journal article
• Publisher: The American Chemical Society (ACS)
• Topic: Atom and Molecular Physics and Optics; Chemical Sciences
• Status: Published
• ISBN/ISSN/Other: ISSN: 1932-7447