Mossbauer Spectroscopy and X-ray Diffraction Study of 57Fe-Labeled Tetrachloroferrate(III)-Based Magnetic Ionic Liquids

Four Fe-57-labeled tetrachloroferrates(III) of organic cations (1-butyl-3-methylimidazolium, 1-allyl-3-methylimidazolium, 1-methyl-1-propylpyrrolidinium, tetraphenylphosphonium) were examined by temperature-dependent Mossbauer spectroscopy. The hyperfine and dynamic parameters of the iron(III) site were determined. Single crystal X-ray diffraction data of [Ph4P][FeCl4] were collected at four temperatures (295, 223, 173, and 123 K), and the dynamics of the iron atom inferred from the Mossbauer data and the single crystal U-i,U-j parameters have been compared.