Synthesis, Crystal Structures And Properties Of Copper Complexes With Pyridine Sulfonic Acid Ligands

Coordination complexes with diverse structures have become the research focus in the field of chemistry due to their wide applications in light, electricity, magnetism, catalysis, ion exchange, biological modeling and molecular sieve adsorption. Microporous three-dimensional metal organic skeleton compounds constructed by pyridine sulfonic acid ligands are new functional materials with good gas adsorption, luminous properties and magnetism, which have potencial application prospect.1. Treatment of4-hydroxypyridine-3-sulfonic acid ligand with copper ion self-assembly under hydrothermal conditions afforded one novel complex [Cu(C5H3NSO4)(H2O)](1). It was characterized by elemental analyses, IR, TG-DTG and X-ray crystallography. And its magnetic property was also studied.The single-crystal X-ray diffraction analysis of1shows that it crystallizes orthorhombic lattice with Pbca space group and Cu adopts a distorted NO4square pyramidal coordination environment surrounded by two sulfonate oxygen atoms, one hydroxy oxygen atom, one pyridine nitrogen atom and one water oxygen atom. The4-hydroxypyridine-3-sulfonic acid ligand adopts η4, μ3coordination mode to link three Cu atoms forming2D layer. There are hydrogen bonds and π-π stacking in the layers, which make the structure more stable. The layers are held together through hydrogen bonds forming supramolecular network. Magnetic studies reveal that complex1shows antiferromagnetic interactions among the Cu(Ⅱ) ions.2. Treatment of4-pyridineethanesulfonic acid ligand and1,10-phen,2,2’-bipy,4,4’-bipy as second ligands with Cu2+ion under hydrothermal conditions afforded three complexes [Cu(phen)(SO4)(H2O)2](2)、[Cu(2,2’-bipy)(SO4)(H2O)2](3)[Cu(4,4’-bipy)2(H2O)4](3-OH-4-pySO3H)2(4). They were characterized by elemental analyses, IR, TG-DTG and X-ray crystallography. And their magnetic properties were also studied.The single-crystal X-ray diffraction analyses show that complexes2 and3have the same coordination mode. The Cu has a distorted N2O4octahedral environment constructed by two nitrogen atoms from1,10-phen or2,2’-bipy, two oxygen atoms from two SO42-ligands and two oxygen atoms from two coordinated water molecules. The SO42-ligand adopts η2, μ2coordination mode to link two Cu atoms forming1D chain along the c-axis direction. Adjacent chains form2D layer through hydrogen bonds between SO42-groups and water molecules. The C-H…O hydrogen bonds interlink the adjacent layers to form3D supramolecular network. The coordination mode of4is different from that of2and3. The Cu adopts a distorted N2O4octahedral coordination environment surrounded by two nitrogen atoms from two4,4’-bipy ligands and four water oxygen atoms. The3-hydroxypyridine-4-sulfonic acid ligand was unbonded in the complex. Hydrogen bonds interlink molecules forming3D supramolecular network. Magnetic studies reveal that complexes2,3and4all show antiferromagnetic interactions among the Cu(Ⅱ) ions.