Synthesis and structural characterization of copper(II) coordination polymers with 1,1,2,2-tetra(pyrazol-1-yl)ethane

•Two types of copper(II) coordination polymers with bitopic ligand were prepared.•1,1,2,2-tetra(pyrazol-1-yl)ethane acts as a cross-linker for {Cu(μ-NO3)} chains.•The shortest distance between the copper(II) ions in coordination polymers is 6.85 Å.

Reaction between 1,1,2,2-tetra(pyrazol-1-yl)ethane (Pz4) and copper(II) nitrate in ethanol at room temperature and in solvothermal conditions (90 °C) lead to coordination polymers of two different structures. A ribbon-like coordination polymer {Cu2(μ2-NO3)2(H2O)4 μ′2-Pz4}n was formed at room temperature in which nitrate ions bind the monomeric units, while Pz4 ligands are responsible for cross-linking of {Cu(μ-NO3)} chains. At 90 °C linear 1D coordination polymer was formed, in which Pz4 ligands bridge copper ions that in addition bear two monodentate nitrate ions.

Graphical abstractTwo new copper(II) coordination polymers with bitopic ligand 1,1,2,2-tetra(pyrazol-1-yl)ethane were prepared and their crystal structure was determinedFigure optionsDownload full-size imageDownload as PowerPoint slide