An Iron(II) Spin Crossover Complex with a Maleonitrile Schiff base‐like Ligand and Scan Rate‐dependent Hysteresis above Room Temperature

A Schiff base-like ligand bearing a maleonitrile backbone was synthesized and converted in two steps to an octahedral iron(II) complex with axial imidazole ligands. Single crystal X-ray structure analysis of this revealed 3D hydrogen bond network based on the NH groups ligands that act as donors. Interestingly, temperature-dependent magnetic measurements showed abrupt spin crossover hysteresis above room temperature. Thereby, width features strong scan rate dependency leading 6 K wide at 5 K/min 1 when measured settle mode. This kinetic effect is further investigated by DSC verifying width. The small additionally followed using PXRD. For comparison, corresponding pyridine well.