Syntheses, Structures And Characterization Of Transition Metal Complexes With Ligands Containing Nitrogen And Oxygen Atoms

The coordination compounds, self-assemble by transition metal ions and ligands containing nitrogen and oxygen atoms, are attracting more attention for their interesting novel structures and properties. The design and synthesis of novel coordination compounds are of important current interest in supramolecular chemistry and crystal engineering. The potentially applications of these compounds will be intensive in the field of molecular self-assemble, molecular recognition, molecular catalysis, magnetism, electrical conductivity, ion exchange and separation etc.In this thesis, according to the principle of crystal engineering and self-assembly, ten coordination complexes, which are never reported and with novel structures and properties, are synthesized and characterized by means of elemental analyses, IR spectra and TGA. Parts of them are also determined by X-ray structural analyses and variable temperature magnetic susceptibility.Using biphenyl-2,2'-dicarboxylate acid (2,2'-bpda) as a main ligand, six coordination polymers are obtained and three of them are determined by X-ray structural analyses. Complex 1 [Mn(2,2'-bpda)(benzidine)]_n is constructed by Mn²+, 2,2'-bpda and benzidine ligands. Each Mn atom is in the center of distorted octahedral geometry, which is coordinated three symmetry-relateded bpdc ligands resulting in a 1-D column. Meanwhile, the adjacent columns are crosslinked by didentate ligand benzidine into a 3-D supramolecule with 1D channels. Complex 2 [Mn₂(2,2'-bpda)₂(benzidine)₃(C₂H₅OH)]_n is a dinuclear complex, which consists of one-dimensional S-shaped subchains (Mn)₂(C₁2H₁2Na)₃ which interlinked by μ3-2,2'-bpda into a 2-D sheet. Complex 3 [Mn2(2,2'-bpda)2(phen)]_n is a novel one-dimensional (1-D) chain coordination polymer, synthesized by hydrothermal reaction. Different from complex 1 and 2 in the crystal structure, manganese atoms display two kind of coordination styles: six coordination and rare five coordination. The later maybe due to the steric block. TGA curve shows that complex 1 and 3 have good thermal stability(complex 1 decomposed temperature is up to 200℃ and 3 is up to 310℃, while complex 2 has poor thermal stability(decomposed at 310℃. Themagnetic susceptibility has been measured and indicates possible antiferromagnetic coupling between adjacent Mn (II).Four complexes, named [Cu2(C7H7O2N)2(Ci2H8N2)2-2H2O]-Cl2