Syntheses, Crystal Structures And Properties Of Transition And/or Lanthanide Coordination Complexes With Pyridyl Derivative Ligands

With the rapid development of crystal engineering discipline and supramolecular chemistry, the design and synthesis of novel functional coordination polymers which have interesting and useful structure have been one of the most interesting research topics in coordination chemistry. The dissertation is aimed to synthesize transition and/or lanthanide coordination complexes with excellent photophysical or magnetic properties and good thermal stabilities. Four series,28transition and/or lanthanide coordination complexes are successfully designed by the reactions of transition metals (Zn??Mn??Co??Ni?) and/or lanthanide ions (Eu??Tb??Dy??Nd??Yb??La??Gd??Pr?) with four different kinds of derivatives of pyridyl derivative ligands. The coordination complexes are characterized by X-ray single crystal diffraction, elemental analyses, IR spectral analyses. Their luminescence properties and magnetism have been investigated, their thermal stabilities have also been studied. The dissertation includes the following five parts:Chapter1:The basic theory and concept of supramolecular chemistry, crystal engineering and coordination polymer are simply introduced. The synthesis of coordination polymer, the factors which affect the synthesis of coordination polymer, the structures of coordination polymers and the practical application of coordination polymers have also been briefly introduced.Chapter2:The2,6-bis(pyrazin-2-yl)pyridine-4-carboxylate (HL1) has been synthesized. Nine novel Zn? coordination complexes (1-9) based on the HL1and aliphatic/aromatic carboxylic acid as auxiliary ligands have been synthesized successfully, and seven lanthanide coordination polymers (10-16) were also based on the HL1and lanthanide ions Eu??Tb?? Dy? etc. The influence factors of auxiliary ligands and reaction conditions have been discussed. The luminescence properties and the thermal stability of the coordination polymers have been also investigated.Chapter3:The ligand4-(2,6-di(pyrazin-2-yl)pyridine-4-yl)-benzoic acid (H2L) was synthesized according to a modified literature procedure. Five novel Zn?/Mn? coordination polymers (17-21) with different structure have been hydrothermally synthesized. The influence factors of different reaction conditions have been discussed. The results is during the construction of the coordination polymers, the auxiliary ligands, pH values, the anions of the metal salts, molar ratio of the reagent, reaction temperature, et, have important influences on the final structures to some extent. The luminescence properties and the thermal stability of the coordination polymers have been also investigated. Chapter4:The ligand2,6-di(pyrazin-2-yl)-4,4'-bipyridine (L3) which has never been reported has been synthesized. Four novel transition metal (Zn?, Mn?) coordination polymers (22-25) based on HL3and carboxylic acid as auxiliary ligands have been hydrothermally synthesized successfully. The hydrogen interactions and ?-? stacking interactions play an important role on the constructing of supramolecular network.Chapter5:The ligand2,6-bis(3-thienyl-3-henylpropionyl)-pyridine (H2L4) was synthesized according to a modified literature procedure using the Claisen condensation reaction. Three novel3d-4f heterotrinuclear complexes with triple-helical architectures (26-28) have been synthesized successfully by the reactions of transition meta and lanthanide ions with H2L4. The research results of the magnetic properties of26and27support the existence of a ferromagnetic exchange interaction between the transition meta and lanthanide ions. In addition, the UV-visible spectra, the PXRD and the thermal stability of the coordination polymers have been also investigated and the results indicate the coordination polymers are pure and possess good thermal stability.