Copper(II) bromide and copper(II) acetate complexes of 4,4′-(p-phenylene)bipyridazine

4,4′‐(p‐Phenylene)bipyridazine, C14H10N4, (I), and the coordination compounds catena‐poly[[dibromidocopper(II)]‐μ‐4,4′‐(p‐phenylene)bipyridazine‐κ2N2:N2′], [CuBr2(C14H10N4)]n, (II), and catena‐poly[[[tetrakis(μ‐acetato‐κ2O:O′)dicopper(II)]‐μ‐4,4′‐(p‐phenylene)bipyridazine‐κ2N1:N1′] chloroform disolvate], {[Cu2(C2H3O2)4(C14H10N4)]·2CHCl3}n, (III), contain a new extended bitopic ligand. The combination of the p‐phenylene spacer and the electron‐deficient pyridazine rings precludes C—H...π interactions between the lengthy aromatic molecules, which could be suited for the synthesis of open‐framework coordination polymers. In (I), the molecules are situated across a center of inversion and display a set of very weak intermolecular C—H...N hydrogen bonds [3.399 (3) and 3.608 (2) Å]. In (II) and (III), the ligand molecules are situated across a center of inversion and act as N2,N2′‐bidentate [in (II)] and N1,N1′‐bidentate [in (III)] long‐distance bridges between the metal ions, leading to the formation of coordination chains [Cu—N = 2.005 (3) Å in (II) and 2.199 (2) Å in (III)]. In (II), the copper ion lies on a center of inversion and adopts CuN2Br4 (4+2)‐coordination involving two long axial Cu—Br bonds [3.2421 (4) Å]. In (III), the copper ion has a tetragonal pyramidal CuO4N environment. The uncoordinated pyridazine N atom and two acetate O atoms provide a multiple acceptor site for accommodation of a chloroform solvent molecule by trifurcated hydrogen bonding [C—H...O(N) = 3.298 (5)–3.541 (4) Å].