Magnetic properties of monomeric and polymeric stannolediide yttrium and erbium complexes

Abstract Lanthanide sandwich complexes are promising candidates for single-molecule magnets, owing to their magnetic anisotropy and slow relaxation of magnetization. Here we show the synthesis and characterization of the polymeric yttrium and erbium complexes ligated by cyclooctatetraendiide and stannolediide ligands. The molecular structures showed the formation of one-dimensional-coordination polymers with the molecular formula of C 40 H 56 KOSi 2 SnLn (Ln = Y, Er), which resemble a trapezoidal wave. Upon encapsulation of the K cations with 2.2.2-cryptand, the respective monomeric sandwich complexes having the molecular formula of C 57 H 87 KN 2 O 6 Si 2 SnLn (Ln = Y, Er) were obtained. The diamagnetic yttrium complexes were characterized by NMR spectroscopy, and the magnetic properties of both Er complexes were studied. The polymeric Er complex demonstrates a lower energy barrier for magnetic relaxation compared to the monomeric erbium complex, despite the similar structural features of the compounds.