Two new iron(III) complexes of the formulas [Fe(bpm)Cl-3(H2O)]. H2O (1) and [Fe-2(bpm)Cl-6(H2O)(2)]. 2H(2)O (2) (bpm = 2,2'-bipyrimidine) have been synthesized and their crystal structures determined by single-crystal X-ray diffraction. 1 and 2 crystallize in the monoclinic system, space group P2(1)/n, with a = 8.593(2) Angstrom, b = 17.669(4) Angstrom, c = 8.928(2) Angstrom, beta = 102.36(2)degrees, and Z = 4 for 1 and a = 6.422(3) Angstrom, b = 11.999(4) Angstrom, c = 12.297(6) Angstrom, beta = 93.82(4)degrees, and Z = 2 for 2. The structure of complex 1 is made up of neutral [Fe(bpm)Cl-3(H2O)] mononuclear units and water molecules of crystallization. The monuclear units an linked through hydrogen bonds involving the coordinated water molecule and one of the chlorine atoms yielding a uniform chain. The iron(III) is hexacoordinate, with two nitrogens of a chelating bpm, three chlorine atoms, and one water molecule building a distorted octahedron around the metal atom. The structure of 2 consists of centrosymmetric bpm-bridged dinuclear [Fe-2(bpm)(Cl-6)(H2O)(2)] units and water molecules of crystallization which are linked through hydrogen bonds leading to a three-dimensional network. The geometry of each metal atom in 2 is distorted octahedral as in 1. The equatorial positions around the metal ion in 1 and 2 are filled by two bpm nitrogens and two chlorine atoms, whereas the axial positions are occupied by a water molecule and a chlorine atom. The shortest intermolecular metal-metal distance in 1 is 5.957(2) Angstrom, and the intramolecular metal-metal separation in 2 is 5.952(1). The magnetic behavior of 1 and 2 has been investigated over the temperature range 1.8-300 I;. Significant antiferromagnetic coupling is observed for both compounds, the susceptibility curves exhibiting maxima at 5.0 (1) and 5.2 K (2). The pathways of the exchange interaction in 1 (hydrogen bonding) and 2 (hydrogen bonding and bridging bpm) are discussed in the light of their crystal structures, and the values of the coupling constants are compared with those of related systems.