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

Three thiophene-2,5-dicarboxylic acid (H2tdc) complexes of copper(II) with 2-aminomethylpyridine (ampy), {[Cu2(μ-tdc)2(ampy)2]·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)·4H2O (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···π interactions in the three complexes.

We have synthesized and structurally characterized three 3D Cu(II) complexes which are derived from 2,5-thiophenedicarboxylate with dissimilar ligands. One of the complexes has a 1-D zigzag polymeric structure and tdc behaves as a bidentate ligand. In the other complexes, the tdc dianion acts as a counter ion. In all these complexes the Cu(II) atom has a distorted octahedral coordination geometry. Three-dimensional frameworks are constructed though hydrogen bonding and/or C–H···π interactions in all the synthesized complexes.Figure optionsDownload as PowerPoint slide