Parts | Days | Selection | Search | Updates | Downloads | Help
MA: Fachverband Magnetismus
MA 19: Poster 1
MA 19.21: Poster
Tuesday, September 6, 2022, 17:30–20:00, P2
57Fe Mössbauer spectroscopy on FePcF16 and its µ-Oxo dimer in catalysis reaction — •Felix Seewald1, Florian Puls2, Hans-Joachim Knölker2, and Hans-Henning Klauss1 — 1Institute of Solid State and Materials Physics, TU Dresden, D-01069, Germany — 2Department Chemie, Technische Universität Dresden, Bergstraße 66, D-01069 Dresden, Germany
Iron-hexadecafluorophthalocyanine (FePcF16) is used as an oxidation catalyst. Understanding its catalysis mechanism is part of current research. The Fe atom is square planar coordinated by four nitrogen atoms. Both FePcF16 and its mu-Oxo dimer ([FePcF16]2O) are already identified as steps of the oxidation cycle.
The Mössbauer spectra of [FePcF16]2O can be described by two sites at room temperature, both exhibiting quadrupole splitting. A temperature dependent reversible transition between both sites can be observed. Below 30 K the onset of a magnetic hyperfine field is observed obtaining a value of BHyp = 48.77(12) T at 4.2 K.
The FePcF16 spectra show one additional third site with a considerable quadrupole splitting and an electric field gradient largest principle component of Vzz = 154(2) V/Å2. This site stays paramagnetic down to 4.2 K.
First measurements of the frozen reaction solution unveil an additional fourth site in a characteristic Fe(II) charge and high spin (S=2) state. We will discuss the implications of these findings on the catalysis process.