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New binuclear cymantrenecarboxylate complexes of rare earth metals, [Ln 2 (μ O,η 2 O 2 CCym) 2 (μ 2 O,O' O 2 CCym) 2 (η 2 O 2 CCym) 2 (DMSO) 4 ] (Ln = Tb (I), Dy (II); Cym = (η 5 C 5 H 4 )Mn(CO) 3 ) and [Ln 2 (μ 2 O,O' O 2 CCym) 4 (η 2 -NO 3 ) 2 (DMSO) 4 ] (Ln = Tb (III), Dy (IV)), are synthe sized and characterized by X ray diffraction analysis. The carboxylate clusters containing the Mn 2+ ion, which is formed due to the destruction of the cymantrenenecarboxylate anion, [Tb 4 (μ 3 OH) 4 (μ 2 O,O' O 2 CCym) 6 (H 2 O) 3 (THF) 4 ][MnCl 4] ⋅ 4CH 2 Cl 2 ⋅ 6THF (V) with the cubane like structure, and [Er 2 Mn(μ 2 O 2 CCym) 6 (η 2 O 2 CCym) 2 ((MeO) 3 PO) 4 ] ⋅ 2MePh (VI) with linear structure, are also obtained. The magne tism of complexes I, II, V, and VI is studied in a direct magnetic field. The magnetic properties of complexes II and VI are studied in direct and alternating magnetic fields. Complex II exhibits the properties of a single molecule magnet. The thermal decomposition of complexes I-IV is studied by differential scanning calorim etry and thermogravimetric analysis. According to the X ray diffraction analysis data, the final thermolysis products of complexes III and IV in air are multiferroics LnMn 2 O 5 .

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New ferrocenoylacetonate complexes of several rare earth elements, [Ln(fca)3(bpy)]·MeC6H5 (Ln = Pr (), Eu (), Gd (), Tb (), Dy (), Ho (), Y (); bpy - 2,2'-bipyridine; Hfca - FcCOCH2COMe) as well as scandium ferrocenoylacetonate [Sc(fca)3]·0.5MeC6H5 (), were synthesized and characterized by single crystal X-ray diffraction analysis. In the crystal lattice of the isostructural complexes , two [Ln(fca)3(bpy)] molecules form a pair due to stacking interactions between the bpy ligands. The Ln(3+) ions are coordinated in a square antiprism geometry with a coordination number of 8. The Sc(3+) ions in complex are coordinated in an octahedral geometry. Thermolysis of complexes was studied under air and argon atmospheres; in the first case, it affords perovskites LnFeO3 as one of the products. Complexes display single-molecule magnet properties, and the effective relaxation barrier for the Dy complex , was found to be Δeff/kB = 241 K, which is one of the highest values obtained for a mononuclear β-diketonate lanthanide complex.

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