Organic Phosphonic Acid And Azide Synthesis, Structure And Properties Of Transition Metal Complexes Study

Coordination complexes have attracted much attention recently, because of their fascinating structural diversity and potencial applications in photics, catalysis, magnetism, adsorbent and molecular recognition.1,Treatment of 3-pyridylphosphonic acid with Co(OAc)2·4H2O under hydrothermal conditions afforded the complex [Co(3-C₅H₄NPO₃)(H₂O)₅], whereas the analogous reaction with Cu(OAc)2·H2O gave [Cu(η4,μ4:3-C₅H₄NPO₃)] in good yield. Compounds [Co(3-C₅H₄NPO₃)(H₂O)₅] and [Cu(η4,μ4:3-C₅H₄NPO₃)] were characterized by various methods including X-ray crystallography, IR and elemental analyses. And their magnetic properties and nonlinear optical properties were also studied.(a) Complex [Co(3-C₅H₄NPO₃)(H₂O)₅] crystallizes in an orthorhombic lattice with Pnma space group. Complex contains molecules of [Co(3-C₅H₄NPO₃)(H₂O)₅] which link each other via hydrogen bonds to form a three-dimensional supermolecular framework; the nonlinear optical properties of [Co(3-C₅H₄NPO₃)(H₂O)₅] were studied with Z-scan technology. The results revealed that it possessed good nonlinearity.(b) Complex [Cu(η4,μ4:3-C₅H₄NPO₃)] crystallized in a monoclinic lattice with P21/c space group. It showed a two-dimensional layer structure, in which each Cu center bridges to another Cu center via two pyridylphosphonato oxygen atoms of bridging ligands to form a one-dimensional ladder of{CuO3N}{CPO3} units. The pyridyl N atom further coordinated to Cu center in the neighboring chain, thus forming a two-dimensional layer; complex showed weak antiferromagnetic interactions between the closest coppers; the nonlinear optical properties of [Cu(η4,μ4:3-C₅H₄NPO₃)] were studied with Z-scan technology.The results revealed that it possessed good nonlinearity.2,In the thesis, azido-metal complexes were also synthesized by the general solution method. They were characterized by various methods including IR, elemental analyses and TG-DTG. And their magnetic properties were also studied (a) Each nickel atom coordinated with the N atoms of the phen ligands and the N atoms of end-on azide groups, and lied in the distorted octahedral environment; complex [Ni(N₃)₂(Phen)₂] showed weak antiferromagnetic interactions between the closest nickels; the complex had higher thermal stability.(b) Each cobalt atom coordinated with the N atoms of the 2,2'-bipyridine ligands and the N atoms of end-end azide groups, and lied in the square pyramidal environment; complex [Co₂(N₃)₂(C₁₀H₈N₂)₂] showed weak ferromagnetic interactions between the closest cobalts; the complex had higher thermal stability.