Synthesis, crystal structure and Hirshfeld surface analysis of catena -poly[[bis-(semicarbazide-κ 2 N , O )copper(II)]-μ-sulfato-κ 2 O : O '].

The title polymer, [Cu(SO 4 )(CH 5 N 3 O) 2 ] n , has been synthesized from aqueous solutions of CuSO 4 and semicarbazide. In the crystal structure, the Cu II atoms are chelated by two neutral semicarbazide mol-ecules through the oxygen atom and a nitro-gen atom of the amino group. The remaining two positions of the Jahn-Teller-distorted octa-hedral coordination sphere are occupied by oxygen atoms of two sulfate anions in the axial positions. The coordination bonds of the latter associate the polyhedra into polymeric chains running parallel to the c axis. There is a weak intra-molecular hydrogen bond between the N-H group and an oxygen atom of the SO 4 2- anion. Thirteen relatively weak inter-molecular hydrogen-bonding inter-actions link the chains into a three-dimensional network. Hirshfeld surface analysis revealed that 64.7% of the inter-molecular inter-actions are from O⋯H/H⋯O contacts and 20.1% from H⋯H contacts. Other inter-actions such as N⋯H/H⋯N or C⋯H/H⋯C contribute less to the crystal packing.