Abstract: | By alternating‐current electrochemical synthesis crystals of {CuH2NC5H4N(C3H5)]Br2} ˙ H2O ( I ), {CuH2NC5H4N(C3H5)]Br0.65Cl1.35} ˙ H2O ( II ) and {CuH2NC5H4N(C3H5)]Cl2} ( III ) π‐complexes have been obtained and structurally investigated. The I and II compounds are isostructural and crystallize in a monoclinic sp. gr. P21/c, I : a = 7.359(2)Å, b = 12.3880(6)Å, c = 13.637(3)Å, β = 107.03(1)°, V = 1188.7(4)Å3, Z = 4 for C8H13N2OBr2Cu composition, R = 0.0293 for 2140 reflections. II : a = 7.2771(6)Å, b = 12.3338(3)Å, c = 13.4366(7)Å, β = 107.632(2)°, V = 1149.3(1)Å3, Z = 4 for C8H13N2Br0.65Cl1.35Cu composition, R = 0.0463 for 2185 reflections. Metal and halogen atoms form centrosymmetric Cu2X4 dimers. Each copper atom is surrounded by three halogen atoms and by a weakly bonded C=C‐group of the onium moiety. Isolated {CuH2NC5H4N(C3H5)]}2X4 dimers are combined into a three‐dimensional network due to a bridging function of water molecules via a system of rather strong hydrogen bonds. Chlorine derivative III crystallizes in another structure type: sp. gr. C2/c, a = 21.568(7)Å, b = 7.260(2)Å, c = 13.331(3)Å, β = 95.65(2)°, V = 2077(2)Å3, Z = 8 for C8H11N2Cl2Cu composition. Copper atom, included in CuCl2— isolated fragment, is coordinated to a C=C‐bond of ligand moiety. N‐H…Cl hydrogen bonds unite CuH2NC5H4N(C3H5)]Cl2 subunits into infinite ribbons. π‐Interaction in III appears to be more effective than in I and II . |