Synthesis, structure, and magnetic properties of a dinuclear antiferromagnetically coupled iron(II) complex

A new dinuclear Fe(II) complex with the general formula [Fe-2(1,4-tpbd)(dca)(4)(H2O)(2)] (1) (in which 1,4-tpbd = N,N,N',N'-tetrakis(2-pyridylmethyl)benzene-1,4-diamine; dca = dicyanamide, [N(CN)(2)](-)), has been prepared under hydrothermal conditions and fully characterized by elemental analysis, infrared spectroscopy, X-ray diffraction, and magnetic measurements. The compound crystallizes in the triclinic system and P-1 space group with Z =1 and the following unit cell parameters: a = 8.165(5) angstrom, b = 10.236(5) angstrom, c = 13.105(5) angstrom, alpha = 81.421(5)degrees, beta = 78.810(5)degrees, gamma = 72.941(5)degrees, and V = 1022.2(9) angstrom(3). The Fe(II) ions are six -coordinated, in distorted octahedral fashion, by three N atoms of tpbd ligand, one water oxygen atom and two N atoms of two dicyanamide anions. The intra-dinuclear Fe center dot center dot center dot Fe distance via the bridged t2-tpbd ligand is 8.293(8) A. In the molecular arrangement, the combination of O-H center dot center dot center dot N and C-H center dot center dot center dot-N hydrogen bonds links the title complex to form a three-dimensional supramolecular structure. Magnetic susceptibility measurements (2-300 K) show that 1 presents weak antiferromagnetic exchange between the two nearest Fe2+ ions with the coupling constant J = 1.05 cm(-1). (C) 2017 Elsevier B.V. All rights reserved.