Achirality in the low temperature structure and lattice modes of tris(acetylacetonate)iron(iii).

Tris(acetylacteonate) iron(iii) is a relatively ubiquitous mononuclear inorganic coordination complex. The bidentate nature of the three acetylacteonate ligands coordinating around a single centre inevitably leads to structural isomeric forms, however whether or not this relates to chirality in the solid state has been questioned in the literature. Variable temperature neutron diffraction data down to T = 3 K, highlights the dynamic nature of the ligand environment, including the motions of the hydrogen atoms. The Fourier transform of the molecular dynamics simulation based on the experimentally determined structure was shown to closely reproduce the low temperature vibrational density of states obtained using inelastic neutron scattering.