Two Polynuclear Manganese(II) Complexes Based on Multidentate N-Heterocyclic Aromatic Ligand and V-Shaped Polycarboxylate Ligand: Synthesis, Crystal Structure Analysis and Magnetic Properties

The reaction of MnCl2, 2-(5-{6-[5-(Pyrazin-2-yl)-1H-1,2,4-triazol-3-yl]pyridin-2-yl}-1H-1,2,4-triazol-3-yl)pyrazine (H(2)ptptp), 4,4 '-sulfonyldibenzoic acid (H(2)sdba) or 4-(4-carboxyphenoxy)phthalate acid (H(3)cpop) and [BMI]Br ionic liquids (BMI = 1-butyl-3-methylimidazolium) gave rise to two complexes, {[Mn-4(ptptp)(2)(sdba)(2)(H2O)(2)]center dot 2H(2)O}(n) (1) and {[Mn-3(ptptp)(cpop)Br(H2O)(2)]center dot 2H(2)O}(n) (2). The compounds have been well characterized by elemental analysis, IR spectra, thermogravimetric analysis, as well as single-crystal and powder X-ray diffraction. The structure feature of 1 is that Mn(II) ions in the [Mn-6(sdba)(2)] loops of V-shaped sdba(2-) ligands are ptptp(2-) ligands, respectively, and a 2D layer is constructed from sdba(2-) and ptptp(2-) ligands. The adjacent 2D layers are connected by O-HMIDLINE HORIZONTAL ELLIPSISN hydrogen bonds to form a 3D supramolecular network. The neighbouring trinuclear Mn(II) clusters in 2 are linked by V-shaped cpop(3-) ligands to give a 2D layer, which is penetrated by ptptp(2-) ligands to form self-threading structure. The results of variable-temperature magnetic studies have shown that the magnetic interactions between the Mn(II) ions in 1 and 2 are mainly due to antiferromagnetic coupling.

Automated summary

Two complexes were obtained through the reaction of MnCl2 with different ligands, which were well characterized by various analytical methods. The structure of complex 1 includes 2D layers and a 3D supramolecular network, while complex 2 exhibits a self-threading structure and 2D layers. The magnetic studies indicate that the magnetic interactions in both complexes are mainly due to antiferromagnetic coupling.