Abstract
Four new disulfoxide‐Ln^III^ complexes, [Ln(L)~2~(NO~3~)~3~]~n~ {Ln = La (1), n = n; Ln = Gd (2), Dy (3) and Yb (4), n = 2}, have been prepared by the reaction of Ln(NO~3~)~3~·__n__H~2~O with meso‐1,3‐bis(ethylsulfinyl)propane (meso‐L) in methanol/triethylorthoformate, and their solid‐state structures were characterized by IR spectroscopy, elemental analyses and X‐ray diffraction. Complex 1 is a 1D double‐bridged chain in which the La^III^ ions are ten‐coordinate and the L ligands adopt both meso and rac configurations, and a bis‐monodentate bridging coordination mode. While complexes 2–4 have isostructural dinuclear structures, in which the Ln^III^ ions are nine‐coordinate and the ligands show two types of coordination fashions and configurations: bis‐monodentate bridging with a meso‐configuration, and monodentate coordination with a rac‐configuration. The structural differences between 1 and 2–4 indicate the influence of lanthanide contraction on the complex structures. In addition, a change in configuration of the ligand occurs when it reacts with metal ions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)