for M = La, Pr, Ce, Nd and U, coupled with the high local symmetries of their metal sites, has provided a rare opportunity to study paramagnetic shifts in an isostructural series of f-block complexes by Si NMR spectroscopy. We find by a combination of single crystal XRD and EPR spectroscopy that in the solid state these complexes show trigonal bipyramidal geometries, with local D3h symmetries of the central MSi3O2 cores and easy-axis magnetic anisotropy. The a combination of characterization methods, we find that the coordinated THF molecules in [M{Si(SiMe3)3}3(THF)2] are readily displaced in solution to give the desolvated species [M{Si(SiMe3)3}3(THF)n] (n = 0 or 1), which show local C3vsymmetric cores and easy-plane magnetic anisotropy. The solution 1 H NMR spectra of [M{Si(SiMe3)3}3(THF)2] in 9 :