Syntheses And Properties Of Lanthanide (Ln) And Ln-Cu/Co Complexes

This thesis is mainly carried out in two aspects: Synthesis and characterizationof lanthanide based coordination polymers and single molecule magnets.Regarding the lanthanide based coordination polymers, using4,4’-dicarboxylate-2,2’-dipyridine （4,4’-H₂BPDC） and5,5’-dicarboxylate-2,2’-dipyridine （5,5’-H₂BPDC） as ligands, five series totally thirty-seven coordinationpolymers were synthesized and characterized. These complexes have beencharacterized by crystal structure, powder diffraction, elemental analysis, TG analysis,fluorescence spectroscopy, hydrogen adsorption and magnetic properties.4,4’-H₂BPDC and5,5’-H₂BPDC ligands react with lanthanide ions separately, andgot three kinds of structures, totally thirteen coordination polymers. And the two Dycontaining compounds （4and8） synthesized by4,4’-H₂BPDC exhibit singlemolecule magnet behaviors. When taking4,4’-H₂BPDC as ligands react with Ln3+and Cu²⁺ions got six isomorphous Ln-Cu heterometallic coordination polymers,which are the first example of two-fold interpenetrating3D3d-4f heterometalliccoordination polymers based on a rigid ligand. The reaction of5,5’-H₂BPDC withLn3+and Cu²⁺got four kinds of structures, totally eleven Ln-Cu heterometalliccoordination polymers, and the structural changes and bond length changes indicatethe existence of lanthanide contraction effect. When using Co²⁺ion instead of Cu²⁺ion, a series of Ln-Co heterometallic coordination polymers are generated, the studyfound that Dy-Co shows single molecule magnet behavior.In the aspect of single molecule magnets, eight novel lanthanide octanuclearclusters with the ligand salicylaldoxime （SaoH₂） have been prepared, and structurallyand magnetically characterized. Magnetic property investigations show that theDy-Sao displays the out-of-phase signal and exhibits slow relaxation of themagnetization. Hysteresis loop measured by micro-SQUID certificated that Dy-Sao isa single molecule magnet.