Synthesis And Properties Of Metal Complexes Based On Nitrogen-containing Heterocyclic Ligands

In recent years,coordination metal complexes with N-heterocyclic ligand have been the subject of intensive investigation not only due to theirintriguing structural diversity,but also because of their potential biological and magnetic properties.?1?The complex [Zn?2,3-PDC??DMIM?·H₂O]_n?1??2,3-P D C = 2,3-Pyridinedicarboxylic acid,DMIM=2-Methylimidazole?was prepared under the condition of 150°C reflux heating.The five coordination mode of central Zn???atom make it to form a square pyramidal structure.The Zn???ions in complex 1are bridged by the 2,3-pyridinedicarboxylic acid ligands to form a one-dimensional chain.There is an interaction between the ligands,so that 2-methylimidazole as a terminal group is suspended on the five membered chelate ring formed by the 2,3-pyridinedicarboxylic acid ligand and the metal center.?2?The complex [Co?2,3-PDC??H₂O?₂]n?2?was prepared under hydrothermal conditionsand heated at 150°C for 4d.The coordination motif of the Co???atom is a distorted octahedron.Two parallel ligands in complex2 are connected with a pair of adjacent Co???atoms in the form of a head to tail connection to form an edge fused ring chain.For both complexes 1 and 2,their chains can be connected into a three-dimensional frame structure through hydrogen bonds.Bothcomplexes have been characterized by elemental analysis,IR spectra and thermogravimetric analysis?TGA?.The results are consistent with the results of crystal analysis.?3?The biological activity test of complex 1 and 2 showed that both of them had some inhibitory effects on some plants.?4?We have investigated the magnetic properties of the complex[Co?2,3-PDC??H₂O?₂]_n?2?by means of broken symmetry?BS?with density functional theory?DFT?.The results show that there is a strong ferromagnetic interaction between dinuclear Co???.