catena-Poly[[tetra-kis-(3,5-dimethyl-1 H-pyrazole-κ N 2)copper(II)]-μ2-sulfato-κ2 O: O']: crystal structure and Hirshfeld surface analysis of a CuII coordination polymer

Acta Crystallogr E Crystallogr Commun. 2022 Mar 24;78(Pt 4):433-438. doi: 10.1107/S2056989022002894. eCollection 2022 Apr 1.

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 aceto-nitrile 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 octa-hedral 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 tetra-hedra. 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%) inter-actions.

Keywords: Hirshfeld surface analysis; coordination polymer; copper; copper complexes; crystal structure; direct synthesis; oxidative dissolution; pyrazole; supra­molecular assembly.

Grants and funding

This work was funded by Ministry of Education and Science of Ukraine grant 22BF037-09.