Coordination Polymer of Ba²⁺ with 2-Furoic Acid Anions: Synthesis, Structure, and Thermal Properties

The reaction of barium(II) hydroxide with 2-furoic acid (pyromucic acid, Hfur) gave 1D coordination polymer {[Ba3(fur)6(Hfur)2(H2O)8]}n·4nH2O (I). According to X-ray diffraction data, I contains two symmetrically independent barium cations, which have different environments: Ba(1) coordinates six fur– anions, while Ba(2) is a fragment of heteroleptic coordination (fur–, Hfur, and H2O) (CIF file CCDC no. 2063380). The supramolecular polymeric architecture of I is determined by bridging water molecules and numerous hydrogen bonds between coordinated and solvation water molecules to form a 1D motif. The arrangement of Ba2+ ions in the trinuclear moiety {Ba3(fur)6(Hfur)2(H2O)8} of the polymer is nearly linear. The thermal behavior of I, investigated by simultaneous thermal analysis (argon atmosphere), showed a stepwise character of thermal decomposition caused by gradual destruction of the hydrogen-bonded framework and the subsequent partial destruction of the organic part. Analysis of the biological activity of I against the non-pathogenic Mycolicibacterium smegmatis strain showed low sensitivity of the bacterial wall to the complex.