Synthesis, Structures And Properties Of Coordination Clusters Based On Schiff Base

In this thesis,we explored the synthesis and the structure of Schiff base coordination compounds.Sixteen clusters were prepared by the reactions of transition and rare earth metal salts with different Schiff base ligands:pentadentate H2L'[o-vanillin-N-?2-hy-droxy-ethyl?ethane diamine]and tetradentate H2L2[o-vanillin-2-aminophenol].A one-dimensional chain-like supermolecule was built based on zero-dimensional Schiff base complound by adjusting the auxiliary ligand and changing the reaction conditions.The structure of complexes 3-5,10 and 11-16 were diterminded by single crystal X-ray diffraction and their formulas are as follows:The mononuclear complexes[Fe?HL¹?₂]Cl with windmill-like structure form 1D supermolecules by H bonds and ?-? stacking interactions.2 is a binuclear copper complex,where the two[Cu-L]is bridged by the auxiliary bbi,and it contains a one-dimensional chain supermolecule by the H bonds.Complexes 3-16 are isostructural tetranuclear[Ni2Ln2]3d-4f heterometallic clusters.The Ni?II?ion has adopted an irregular octahedral geometry with an 05N donor set,while the Ln???ion has a distorted square antiprismatic geometry with an 07N donor set.The core of compound[Ni₂Dy₂O₆]can be described in terms of defect-dicubane?or butterfly topology?with Ni???ions and Dy???ions bridged by the ?2-O or ?3-O ion.The monomolecular Schiff base complexes 3-10 with different anion regulators form a one-dimensional chain coordination supermolecule?complexes 11-16?via hydrogen bonds and ?-? stacking interactions between molecules.Complex 12 exhibits ferromagnetic interactions.During the experiment,we find that the crystal structure may related to the auxiliary ligands which disturb the growing environment of the complex in the way of competitive effect and its contribution to the pH of the solution system,and the adding order of the reactants during the reaction process.