Synthesis, Crystal Structure and Magnetic Property of [Mn2(mal)2(H2O)2(µ2-hmt)] n : A Novel Three-Dimensional Network Self-Assembled by hmt (hmt = Hexamethylenetetramine and mal = Malonate)

A novel three-dimensional coordination polymer [Mn2(mal)2(H2O)2(μ2-hmt)] n (hmt = hexamethylenetetramine, and mal = malonate) was synthesized and characterized by elemental analysis, crystal structure, IR, TG-DTA and magnetic susceptibility. The compound [Mn2(mal)2(H2O)2(μ2-hmt)] n crystallizes in the orthorhombic system, space group 12 mm, with a = 7.1059(11), b = 7.6986(6), c = 15.9824(13) A, and Z = 2. Mn(II) ion has octahedral geometry coordinated by four oxygen atoms from three malonate, one oxygen atom of water and one nitrogen atom of hmt ligand. The two oxygen atoms of each malonate coordinate to the same Mn(II) ion and the other two oxygen atoms connect to two adjacent Mn(II) ions to form an infinite layer. These layers are bridged by the μ2-hmt ligands to form a three-dimensional structure. The magnetic susceptibility data show that there is an antiferromagnetic exchange interaction in the title compound.