2-ethylenediammonium dichloride (1) and dibromide (2) were prepared by the reaction of N,N,N ,N -tetramethyl-1,2-ethylenediamine and the corresponding 1-halopropane. The structures of the compounds were characterized by single-crystal X-ray diffraction. 1 · 2H 2 O crystallizes in the triclinic crystal system, space group P1, with Z = 1, and 2 in the monoclinic crystal system, space group P2 1 /c, with Z = 2. The crystal structures of the salts consist of discrete dications and halide anions. The packing in 1 · 2H 2 O consists of layers of cations with the chloride anions and water molecules forming hydrogen-bonded chains between the cation layers. In 2, the strongest H···Br hydrogen bonds of 2.8138(6) and 2.8187(7)Å link the cations and anions into doublestranded chains. In both salts, cations and anions are also linked together by a further weak C-H···Cl/Br hydrogen bonding network.

The asymmetric unit of the title compound, (C14H34N2)[Fe2Cl6O], contains one complete cation, two half-cations and two anions. The two half-cations are completed by crystallographic inversion symmetry. The FeIII atoms adopt fairly regular FeCl3O tetra­hedral geometries, although the bridging Fe—O—Fe bond angles differ significantly in the two anions, which both adopt an eclipsed conformation. In the crystal, the components are linked by C—H⋯Cl and C—H⋯O inter­actions.

The crystal structure of the title compound, (C12H30N2)[CoCl4], is composed of discrete (C12H30N2)2+ cations and [CoCl4]2− anions. The asymmetric unit contains a half-cation and a half-anion. The atoms of the cation occupy general positions about an inversion centre, which is located at the midpoint of the central C—C bond. The Co atoms lie on a twofold rotation axis. The slightly distorted tetra­hedral coordination environment around the metal atom consists of two Cl atoms and their symmetry-related pairs.