catena-Poly[[tetrakis(3,5-dimethyl-1H-pyrazole-κN2)copper(II)]-μ2-sulfato-κ2O:O′]: crystal structure and Hirshfeld surface analysis of a CuII coordination polymer

Abstract

The title coordination polymer, [Cu(SO4)(C5H8N2)4]n, was synthesized using a one-pot reaction of copper powder, anhydrous copper(II) sulfate and 3,5-dimethyl-1H-pyrazole (Hdmpz) in acetonitrile under ambient conditions. The asymmetric unit can be described as a chain consisting of four [Cu(SO4)(Hdmpz)4] formula units that are connected to each other by a μ2-sulfato-bridged ligand. The octahedral coordination geometry (O2N4) of all copper atoms is realized by coordination of four pyrazole ligands and two sulfate ligands. Four pyridine-like N atoms of the pyrazole ligands occupy the equatorial positions, while two oxygen atoms of two sulfate ligands are in axial positions. As a result of the sulfate ligand rotation, there is a pairwise alternation of terminal O atoms (which are not involved in coordination to the copper atom) of the SO4 tetrahedra. The Cu...Cu distances within one asymmetric unit are in the range 7.0842 (12)–7.1554 (12) Å. The crystal structure is built up from polymeric chains packed in a parallel manner along the b-axis direction. Hirshfeld surface analysis suggests that the most important contributions to the surface contacts are from H...H (74.7%), H...O/O...H (14.8%) and H...C/C...H (8.2%) interactions.

Keywords

• copper
• copper complexes
• pyrazole
• coordination polymer
• hirshfeld surface analysis
• supramolecular assembly
• direct synthesis
• oxidative dissolution
• crystal structure