ABSTRACT: The title compounds, [FeCl2(C15H20N2)4], (I), [FeBr2(C15H20N2)4], (II), and [FeBr2(C15H20N2)4]·2C4H10O, (IIb), respectively, all have triclinic symmetry, with (I) and (II) being isotypic. The Fe(II) atoms in each of the structures are located on an inversion center. They have octa-hedral FeX 2N4 (X = Cl and Br, respectively) coordination spheres with the Fe(II) atom coordinated by two halide ions in a trans arrangement and by the tertiary N atom of four aryl-imidazole ligands [1-(2,6-diiso-propyl-phen-yl)-1H-imidazole] in the equatorial plane. In the two independent ligands, the benzene and imidazole rings are almost normal to one another, with dihedral angles of 88.19?(15) and 79.26?(14)° in (I), 87.0?(3) and 79.2?(3)° in (II), and 84.71?(11) and 80.58?(13)° in (IIb). The imidazole rings of the two independent ligand mol-ecules are inclined to one another by 70.04?(15), 69.3?(3) and 61.55?(12)° in (I), (II) and (IIb), respectively, while the benzene rings are inclined to one another by 82.83?(13), 83.0?(2) and 88.16?(12)°, respectively. The various dihedral angles involving (IIb) differ slightly from those in (I) and (II), probably due to the close proximity of the diethyl ether solvent mol-ecule. There are a number of C-H?halide hydrogen bonds in each mol-ecule involving the CH groups of the imidazole units. In the structures of compounds (I) and (II), mol-ecules are linked via pairs of C-H?halogen hydrogen bonds, forming chains along the a axis that enclose R 2 (2)(12) ring motifs. The chains are linked by C-H?? inter-actions, forming sheets parallel to (001). In the structure of compound (IIb), mol-ecules are linked via pairs of C-H?halogen hydrogen bonds, forming chains along the b axis, and the diethyl ether solvent mol-ecules are attached to the chains via C-H?O hydrogen bonds. The chains are linked by C-H?? inter-actions, forming sheets parallel to (001). In (I) and (II), the methyl groups of an isopropyl group are disordered over two positions [occupancy ratio = 0.727?(13):0.273?(13) and 0.5:0.5, respectively]. In (IIb), one of the ethyl groups of the diethyl ether solvent mol-ecule is disordered over two positions (occupancy ratio = 0.5:0.5).