Structural and Magnetic Studies on Lanthanide Bis(benzoxazol-2-yl)methanides

We describe the syntheses, solid-state structures, and magnetic properties of lanthanide(III)-tris(bis(heterocyclo)methanides) [(THF)M{(NCOC6H4)(2)CH}(3)], with M=Tb (1), Dy (2), Ho (3), and Er (4), respectively. The corresponding lanthanide bis(trimethylsilyl)amides have been prepared as starting materials to deprotonate the neutral bis(benzoxazol-2-yl)methane ({NCOC6H4}(2)CH2) at the central methylene bridge to generate the monoanionic ligand. In the course of this investigations the hitherto unknown holmium tris(bis(trimethylsilyl)amide) is communicated in here. X-ray diffraction data of 1-4 demonstrate an almost planar ligand with metal coordination in an N,N'-chelating fashion. Different to their d-metal analogous the magnetic data of the f-metal complexes presented here show no single-molecule magnet (SMM) properties.