Influence of CF3 Substituents on the Spin Crossover Behavior of Iron(II) Coordination Polymers with Schiff Base‐like Ligands. Issue 13 (26th March 2020) - Kurz, Hannah
Abstract : A Schiff base‐like ligand bearing CF3 substituents was synthesized and converted to iron(II) coordination polymers [{FeL(Lax )} n ] using five different bridging ligands Lax . The structure of the coordination polymers was investigated using powder X‐ray diffraction and single‐crystal X‐ray diffraction in the case of [{FeL(bipy)} n ]. The later revealed an untypical ABAB pattern of alternating equatorial ligands rotated by 180° with regard to each other along the chain. The temperature‐dependent magnetic behavior was investigated with a SQUID magnetometer and the spin states at room temperature were confirmed by 57 Fe‐Mössbauer spectroscopy. Three out of five coordination polymers show spin crossover behavior in the temperature range between 50 and 400 K with different kind of curve progressions (abrupt, gradual, step‐wise). The other two coordination polymers are either fully highspin or fully low spin. Abstract :