Synthesis, crystal structure and Hirshfeld surface analysis of a new copper(II) complex based on diethyl 2,2′-(4H-1,2,4-triazole-3,5-di­yl)di­acetate

The synthesis and crystal structure of a new dinuclear copper(II) complex based on ethyl 2,2′-(1H-1,2,4-triazole-3,5-di­yl)-di­acetate is reported. Additionally, the results of a Hirshfeld surface analysis of [Cu₂(C₆H₅N₃O₄)₂(H₂O)₄]·2H₂O are described.

The title compound, bis­[μ-2,2′-(4H-1,2,4-triazole-3,5-di­yl)di­acetato]­bis­[di­aqua­copper(II)] dihydrate, [Cu₂(C₆H₅N₃O₄)₂(H₂O)₄]·2H₂O, is a dinuclear octa­hedral Cu^II triazole-based complex. The central copper atoms are hexa-coordinated by two nitro­gen atoms in the equatorial positions, two equatorial oxygen atoms of two carboxyl­ate substituents in position 3 and 5 of the 1,2,4-triazole ring, and two axial oxygen atoms of two water mol­ecules. Two additional solvent water mol­ecules are linked to the title mol­ecule by O—H⋯N and O⋯H—O hydrogen bonds. The crystal structure is built up from the parallel packing of discrete supra­molecular chains running along the a-axis direction. Hirshfeld surface analysis suggests that the most important contributions to the surface contacts are from H⋯O/O⋯H (53.5%), H⋯H (28.1%), O⋯O (6.3%) and H⋯C/C⋯H (6.2%) inter­actions. The crystal studied was twinned by a twofold rotation around [100].