Synthesis, structure, solid-state thermolysis, and catalytic properties of binuclear Ce, Nd, Eu, and Gd cymantrenecarboxylate complexes with DMSO

New rare-earth cymantrenecarboxylate complexes [Ln2(μ,η2-O2CCym)2(μ2-O2CCym)2-(η2-O2CCym)2(DMSO)4] (Cym = (η5-C5H4)Mn(CO)3, Ln = Ce (1), Nd (2), Eu (3), Gd (4)) were synthesized and characterized by X-ray diffraction. In dimeric structures 1–4, two of four bridging carboxylates are chelating-bridging, and Ln atoms have coordination number 9. The catalytic activity of complex 2 in the polymerization of 2,3-dimethyl-1,3-butadiene was investigated. The thermal decomposition of the synthesized compounds was studied by DSC and TGA. According to the X-ray powder diffraction data, the final thermal decomposition product of 1 in air consists of CeO2 and Mn3O4. Under the same conditions, complexes 2–4 afford mixtures of LnMn2O5 and Mn2O3.