Spin frustration and concealed asymmetry: structure and magnetic spectrum of [Fe_3O(O_2CPh)_2(py)_3]ClO_4.py

摘要

The oxo-centred trinuclear complex [Fe_3O(O_2CPh)_2(py)_3]ClO_4.py and its fully deuteriated analogue have been synthesized. X-Ray crystallography at T = 233 K shows that the complex has threefold symmetry, space group P6_3/m. Incoherent inelastic neutron scattering spectra at T = 1.5 K however show the presence of two inequivalent sets of moleucles, one a static "isosceles" coupled system, with two J values for the three metal-metal interfactions, the other a dynamic system, with reapid pseudorotation between equivalent isosceles geometries. Combining infrared and neutron scattering data, the distortionof the cluster has been estimated.