Aylin Mutlu

Syntheses, spectral, thermal and structural characterization of copper(II) complexes of 2,3-pyrazinedicarboxylate with N , N ′-dimethylethylenediamine and 1,10-phenanthroline

Two copper(II) complexes of 2,3-pyrazinedicarboxylate (pzdca) with N,N′-dimethylethylenediamine (dmen), [Cu2(pzdca)2(H2O)2(dmen)2] · 6H2O (1) and 1,10-phenanthroline (phen), [Cu(pzdca)(phen)2] · 5.5H2O (2), have been prepared and characterized by elemental analyses, IR, UV/vis, magnetic measurement and single crystal X-ray diffraction. The complexes crystallize in the monoclinic space group P21 /c and triclinic space group P 1, respectively. In both complexes the copper coordinates pyrazine nitrogen and carboxylate oxygen as a bidentate ligand. The coordination sphere around Cu(II) is completed by two N atoms from dmen and four N atoms from phen groups and one axial position occupied by the carboxyl O atom from the symmetry related molecule in 1. The coordination sphere should be described as a distorted octahedral and (5 + 1)-geometry in 1 and distorted octahedral geometry in 2. While 1 shows a first dimeric arrangement, 2 is a monomer. The thermal analyses show that 1 and 2 decompose completely in four and five step thermal processes at 20–600°C temperature intervals.

Copper(II)-pyrazine-2,3-dicarboxylate Coordination Polymer with Monoethanolamine, [Cu(μ3-pzdc)(mea)]n

A novel Cu(II)-pyrazine-2,3-dicarboxylate complex with monoethanolamine ligand (mea), [Cu(μ3-pzdc)(mea)]n(1), has been synthesized and characterized by elemental, spectral (IR and UV–Vis.) and thermal analyses. The molecular structure of polynuclear complex has been determined by the single crystal X-ray diffraction technique. The pyrazine-2,3-dicarboxylate dianion exhibits tetradentate-μ3 bridging ligand through three carboxylate oxygens and one nitrogen atom. The complex contains two copper(II) ions that exhibit two different coordination environments with two mea, two pzdc ligands, respectively. The Cu1(II) ion is coordinated by two carboxylate oxygen atoms, two N atoms and two O atoms of symmetry related carboxylate group, forming a distorted octahedral geometry, while Cu2(II) ion is coordinated by two bidentate mea ligands and remaining two coordination sites of distorted octahedral geometry are occupied by two carboxylate oxygen atoms of neighboring Cu1 molecule. Thermal analysis property and thermal decomposition mechanism of complex have been investigated by using thermal analyses techniques (TG, DTG and DTA).Graphical AbstractWe have synthesized and structurally characterized a novel 2D Cu(II)-pyrazine-2,3-dicarboxylate coordination polymer with monoethanolamine ligand (mea), [Cu(μ3-pzdc)(mea)]n. The pyrazine-2,3-dicarboxylate ligand exhibits tetradentate-μ3 bridging ligand through three carboxylate oxygens and one nitrogen atom. The complex contains two copper(II) ions that exhibit two different coordination environments with two mea, two pzdc ligands, respectively. The crystal packing of complex is a composite of intra- and intermolecular hydrogen bonding and C–O···π interactions.The molecular structure of [Cu(μ3-pzdc)(mea)]n