Synthesis, Structure And Fluorescence Of Lanthanide Complexes Of 4-acyl Pyrazolone Hydrazone And Hydrazide

Coordination chemistry is one of the most active research fields. The design, synthesis and relative properties of functional coordination compounds are focus in the field of coordination chemistry. Rare earth elements are a group of special inorganic ions with good luminescent, electronic and magnetic properties. So it is important to study their functional complexes. Recently, the design and synthesis of functional complexes with lanthanide and their application in electroluminescent devices and luminescent probes have attracted much attention in the study of supramolecule chemistry and biochemistry. 4-acyl-pyrazolone derivatives are broadly used in many fields in the society; meanwhile, compounds of hydrazone and acylhydrazone exhibit different coordination modes and also possess biological activity. So it is an important significance for the formation and study of lanthanide complexes using the combination of 4-acyl pyrazolones and salicylidene hydrazone or hydrazine.In the hunt for obtaining superior complexes with novel architectures and fluorescence, and amplifying the scope of 4-acyl pyrazolone derivatives coordinated with rare earth, five novel 4-acyl pyrazolone derivatives and their lanthanide complexes have been synthesized and characterized on the basis of elemental analyses, thermal analyses and single crystal X-ray diffractions. The general formula of the complexes and the crystal structures were ensured. The fluorescence properties of the complexes have also been investigated simply. There is three parts in this dissertation:1. Four lanthanide complexes of PMPP-SAH (1-phenyl-3-methyl-4-(salicylidene hydrazone) -propionyl-5-pyrazolone) have been synthesized and characterized by elemental analyses, TG-DTA and single crystal X-ray diffractions. We found that the starting ligand PMPP-SAH changed into PMPP in the forming process of complexes and there is a cleavage of the C=N bond. And the mechanism of this cleavage is presumed. We presumed that the driving force for this cleavage may be the hydrolysis catalyzed by lanthanide ions in hydrothermal synthesis according to the correlative references. The H2O attacks at the lively carbon atoms as a nucleophilic reagent and leads to a hydrolysis under hydrothermal conditions sometimes. In our work, this hydrolysis action may occur at C=N bond whereas the lanthanide ions may act as Lewis acid to catalyze the above reactions.2. Four ligands N(1-phenyl-3-methyl-4-benzal/acetyl/propionyl/benzylacetyl- pyrazolone-5)-salicylidene hydrazide and its 24 lanthanide complexes were synthesized and characterized by elemental analyses, TG-DTA and single crystal X-ray diffraction. The analytic results show that salicylidene hydrazide has good coordination performance. And all these complexes are mononuclear complexes.3. The fluorescence of the complexes synthesized in part 2 in solid state was investigated at room temperature. The high efficiency indicates the complexes we prepared may be good candidate for highly fluorescent materials. There is a discussion of the fluorescent type of the complexes; meanwhile, the effect of different 4-acyl and different substitute groups of third and bottom position on the fluorescence of complexes has been analyzed. And found that the complexes have a better fluorescence when there is 4-benzylacetyl, methyl in third position and salicylidene hydrazide in bottom position. So, we expect to obtain the condition to design the best fluorescent lanthanide complexes with 4-acyl-pyrazolone derivatives.