A spin crossover FeII4L6 cage based on pyridyl-hydrazone sites

Abstract

First Fe II -based supramolecular cage with pyridine-hydrazone coordination sites and large cavity volume (306 Å 3 ) exhibits temperature induced spin crossover behaviour. Reported here is the first Fe II based supramolecular cage with pyridyl-hydrazone ligand scaffolds that exhibits temperature induced spin crossover behaviour. Density functional theory calculations were employed to investigate the cause of the occurrence of this phenomenon based on the ligand structure. These results indicate that the reported low-spin cages with pyridyl-imine sites could be reconsidered for spin crossover by carefully manipulating the functional groups in the ligand system.