Gd(III) and Sm(III) 1D Coordination Polymers with 2-Furoic Acid: Synthesis, Structures, and Thermal Behavior

New coordination polymers with lanthanide ions [Ln(Fur)3(H2O)x]n⋅Solv (Ln = Gd (I), Sm (II); Fur = 2-furoic acid anion; x = 2 (I), 3 (II); Solv = MeCN (I)) are synthesized. The structures of the synthesized compounds are determined by X-ray diffraction (CIF files CCDC nos. 2130014 (I) and 2130015 (II)). The coordination environment of the complexing agent (LnO8) corresponds to a distorted square antiprism (I) or a distorted triangular dodecahedron (II). Complexes I and II represent polymeric chains in which the Fur– anions perform the bridging function. The crystal lattice is stabilized by intra- and intermolecular hydrogen bonds between the coordinated water molecules, acid anions, and solvate molecules. The study of the thermal behavior of compound I by simultaneous thermal analysis in an argon atmosphere shows a low stability of the complex: its decomposition starts at 69°С, and the organic moiety destructs gradually without pronounced thermal effects. According to the data of X-ray photoelectron spectroscopy, gadolinium(III) oxide is the final product of thermal decomposition.