SKM 2023 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 19: Molecular Magnetism I

MA 19.6: Vortrag

Dienstag, 28. März 2023, 16:30–16:45, HSZ 04

Magnetic coupling of guest metallocene molecules with SURMOF-2 host matrix — •Alexei Nefedov¹, Chun Li¹, Kai Müller¹, Anemar Bruno Kanj¹, Lars Heinke¹, Chen Luo², Kai Chen², Florin Radu², Evangelos Golias³, Wolfgang Kuch³, and Christof Wöll¹ — ¹Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany — ²Helmholtz-Zentrum Berlin für Materialen und Energie, Berlin, Germany — ³Freie Universität Berlin, Berlin, Germany

Metal-organic frameworks (MOFs) are crystalline and porous, molecular solids consisting of metal nodes and organic ligands. In the case of surface-anchored MOF-2 (SURMOF-2) systems the Cu²⁺ ions are connected via carboxylate and OH groups in a zipper-like fashion. This unusual coupling of the spin-1/2 ions within the resulting 1-D chains stabilizes a low-temperature ferromagnetic (FM) phase. In this study, the magnetic properties of SURMOF-2 systems (Cu(bdc) and Cu(bpdc)) were investigated using X-ray magnetic circular dichroism both in the absorption and in the scattering geometry. Taking advantage of the element sensitivity of this technique it was established that the magnetic signal originates from Cu²⁺ ions. After loading of SURMOF-2 with metallocene molecules, the magnetic properties of the SURMOF were found to be substantially changed. In the case of nickelocene loading, a polarization effect was found resulting in ferromagnetic ordering of the guest molecules. However, the polarization effect is not observed in the case of manganocene derivatives, these molecules remained in their paramagnetic state.