Furancarboxylate Coordination Polymers of Gd3+ and Eu3+: Synthesis, Structural Variations, and Biological Properties

Abstract

A series of polymer complexes of Gd(III) and Eu(III) with 3-furancarboxylic (HFur) and 5-nitro-2-furancarboxylic (HNfur) acids differed in the composition and coligands presented by solvent molecules(CH3OH/C2H5OH/H2O) is synthesized: [Gd(Fur)3(CH3OH)(C2H5OH)]n (I), [Gd(Nfur)3(CH3OH)2]n·CH3CN (II), [Eu(Fur)3(C2H5OH)]n (III), and [Eu(Nfur)3(H2O)2]n·3CH3CN (IV). According to the X-raydiffraction (XRD) data, all complexes are 1D coordination polymers in which the lanthanide cation has thecoordination number 8 (LnO8) to form the environment as a doubly augmented triangular prism (I, II) or asquare antiprism (III, IV). The supramolecular levels of the polymers are stabilized due to intra- and intermolecularhydrogen bonds between the coordinated solvent molecules and O atoms of the chelate-boundanions of the acid and via two types of noncovalent C–H…O and N–O…π interactions that significantly contributeto an additional stabilization of the crystal packings. The biological properties of complexes I, II, andIV are studied with respect to the model nonpathogenic strain Mycolicibacterium smegmatis.