1,1-Cyclohexanediacetate as New Bridging Ligand for Assembling of Homo- and Heterometallic Molecular Complexes with Cu 3 II , Cu 2 II Ln 2 III (Ln = Sm or Gd) and Ni 2 II Gd 2 III Cores: Synthesis, Structure and Magnetic Properties

Interaction of [Cu2(Piv)4(HPiv)2] (Piv− = pivalate) with tetrabutylammonium salt of 1,1-cyclohexanediacetate (Chda2−) and 2,2-bipyridine (2,2′-bpy) in acetonitrile led to formation of the trinuclear homometallic complex [Cu3(2,2′-bpy)2(Chda)2(Piv)2]·2MeCN·0.4H2O (1·2MeCN·0.4H2O). In similar conditions but in presence of [Ln2(Piv)6(HPiv)7] tetranuclear heterometallic complexes [Ln2IIICu2II(2,2′-bpy)2(Chda)2(Piv)6] (Ln = SmIII, 2·2MeCN, or GdIII, 3·2MeCN·5H2O) and [Gd2IIINi2II(2,2′-bpy)2(Chda)2(Piv)6] (4) were synthesized. Carboxylic groups in Piv− and Chda2− act as bridges between the metal ions in all complexes. Temperature dependencies of magnetic susceptibilities and room-temperature solid-state ESR spectra of compounds 2·2MeCN, 3·2MeCN·5H2O, 4 were studied and analyzed.