Syntheses, crystal structures and magnetic properties of 1D and 2D cobaltous coordination polymers with mixed ligands

Abstract

Two new Co(II) coordination polymers with mixed ligands, {[Co(BTA) 0.5(DBI) 2]·DBI·H 2O} n ( 1) and [Co(PDA)(DBI)(H 2O)] n ( 2) (H 4BTA = benzene-1,2,4,5-tetracarboxylic acid; H 2PDA = 2,2′-(1,2-phenylene)diacetic acid; DBI = 5,6-dimethyl-1 H-benzoimidazole) have been synthesized under hydrothermal conditions, respectively. Both of them are characterized by elemental analyses, powder X-ray diffraction, thermogravimetric analysis, single-crystal X-ray diffraction, and magnetic susceptibilities. In 1, the Co(II) ions are four-coordinated and lie in distorted tetrahedron coordination environment. 1D ladder-like chain structure is formed by the bridging BTA 4− ligand. In 2, the Co(II) ions are in slightly distorted octahedral coordination geometry, and linked by PDA 2− ligand exhibiting a 2D layer structure. Temperature-dependent magnetic susceptibility measurements of 1 and 2 revealed that there are antiferromagnetic interactions between Co(II) ions.