Synthesis, crystal structure, spectroscopic, thermal analyses and biological properties of novel F-block coordination polymers containing 2,2′-thiodiacetic acid and piperazine

Three new 1D and 2D coordination polymers, {(pipH(2))[Ce-2(tda)(4)(H2O)(2)]center dot 2H(2)O}(n) (1), {[Nd-2(tda)(3)(H2O)(2)]center dot H2O}(n) (2) and {(pipH(2)) [UO2(tda)(2)]}(n) (3), where [tdaH(2) = 2,2'-thiodiacetic acid and pip = piperazine] have been synthesized and characterized by elemental analysis, spectral (IR, NMR, UV-Vis and luminescence), thermal (TGA/DTA) analysis, as well as X-ray single crystal diffraction. Compounds 1 and 3 are proton transfer salts of the piperazindiium cation and metal complex anions that crystallized in a solution from dicarboxylic acid, piperazine and metal nitrates or acetates as starting materials. However compound 2 is an interesting neutral 2D coordination polymer containing just 2,2'-thiodiacetate dianions. The acid is coordinated to metal center in a bidentate fashion in 2 and 3 while in 1, coordinated to metal center as bidentate and tridentate, simultaneously. The coordination polyhedron around metal center in 1, 2 and 3 can be described as distorted tricapped trigonal prismatic and distorted hexagonal bipyramidal, respectively. The complicated hydrogen bonding networks connected the various components of 1-3 into a 3D-supramolecular architecture. The 1-3 compounds, tdaH2, pip and metal salts were additionally tested in vitro against three Gram-positive microorganisms (Staphylococcus aureus, Staphylococcus epidermidis and Bacillus subtilis) and three Gram-negative microorganisms (Escherichia coli, Serratia marcescens, and Pseudomonas aeruginosa) to assess their antibacterial properties. The results of antibacterial assays indicated that compound 1 has higher activity than compounds 2 and 3 against the tested Gram-positive bacteria and also compound 2 has better activity compared to 1 and 3 against the tested Gram-negative bacteria. (C) 2016 Elsevier B.V. All rights reserved.