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 title compound, bis[μ-2,2′-(4 H -1,2,4-triazole-3,5-diyl)diacetato]bis[diaquacopper(II)] dihydrate, [Cu 2 (C 6 H 5 N 3 O 4 ) 2 (H 2 O) 4 ]·2H 2 O, 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].