Three copper(II) complexes of thiophene-2,5-dicarboxylic acid with dissimilar ligands: Synthesis, IR and UV-Vis spectra, thermal properties and structural characterizations

摘要

Three thiophene-2,5-dicarboxylic acid (H(2)tdc) complexes of copper(II) with 2-aminomethylpyridine (ampy), {[Cu-2(mu-tdc)(2)(ampy)(2)]center dot 2DMF}(n) (1), ethylenediamine (en), trans-[Cu(H2O)(2)(en)(2)](tdc) (2) and 4-methylimidazole (4-meim), trans-[Cu(H2O)(2)(4-meim)(4)](tdc)center dot 4H(2)O (3) have been synthesized and characterized by spectral (IR, UV-Vis), thermal analyses and X-ray diffraction techniques. In 1, thiophene-2,5-dicarboxylate acts as a bridging bis(bidentate) ligand through four carboxylate oxygen atoms forming a 1-D zigzag polymeric chain, whereas in 2 and 3 the tdc dianion behaves as a counter ion. In all cases, the Cu(II) centers have an octahedral coordination geometry. Three-dimensional frameworks are constructed though hydrogen bonding and/or C-H center dot center dot center dot pi interactions in the three complexes.