Synthesis And Properties Of Novel Acylhydrazone Compounds And Their Complexes With Europium And Terbium

Acylhydrazone compounds have been widely applied in the area of medicine,functional materials, because of its various forms of coordination and strong ability ofcoordination, excellent biological activity. To carry out the study and application ofthis acylhydrazone compounds have great significance. Seven novel3-acetyl-coumarin-phenoxyacylhydrazone derivatives and their complexes with Eu(III)and Tb(III) were prepared in this paper. The fluorescence properties andelectrochemical properties of the complexes were also studied by luminescent spectraand cyclic voltammetry. Six novel3,6-diacetyl-carbazol-diacylhydrazone were alsoprepared. The synthesis conditions were explored. The important work andinnovational ideas are following:(1) The3-acetyl-coumarin was synthesized from salicylaldehyde and ethylacetoacetate, by the reaction of Perkin. Meanwhile, the chloroacetic acid was treatedwith p-substituted phenol to yield the p-substituted phenoxyacetic acid, then thephenoxyacetohydrazides were obtain via the reaction of esterification andhydrazinolysis. Then a series of novel3-acetyl-coumarin-phenoxyacylhydrazonederivatives were synthesized by the reaction of3-acetyl-coumarin and p-substitutedphenoxyacetohydrazide and they were characterized by1H NMR,13C NMR, elementalanalysis, mass spectra and infrared spectra. Their corresponding complexes with Eu(III)and Tb(III) were also prepared and characterized by molar conductivity, elementalanalysis, UV-Vis spectra, EDTA titrimetric analysis, infrared spectra, and as well asthermal analysis.(2) The fluorescence properties of the Eu(III) and Tb(III) complexes wereinvestigated by fluorescence spectra, and the effect of the structure of the targetcompounds on properties of the complex was studied. The results indicate that thefluorescence intensity of Eu(III) complexes were more higher than the fluorescenceintensity of Tb(III) complexes. The fluorescence intensity of Eu(III) complexessubstituted by the electrophilic elecrton group of the corresponding ligand wasincreased, whereas, the fluorescence intensity of Eu(III) complexes substituted by thedonative group of the corresponding ligand was decreased. The fluorescence intensityof the Eu(III) complexes with the bromine substituted is best. Compared with theEu(III) complexes, the fluorescence intensity of Tb(III) complexes were reverse, The fluorescence intensity of the Tb(III) complexes with the methoxy substituted is best.The fluorescence quantum yields of the title complexes were calculated by thereference method, the results show that the Eu(III) complexes substituted by theelectrophilic group possess higher fluorescence quantum yield, while the complexessubstituted by the donative elecrton group possess lower fluorescence quantum yield,Compared with the Eu(III) complexes, the fluorescence quantum yields of Tb(III)complexes were reverse. The electrochemical properties of the complexes wereinvestigated by cyclic voltammetry, the results indicate that the HOMO energy leveland LUMO energy level of the complexes substituted by the electrophilic group ishigher than that of the complexes substituted by the donative elecrton group.(3) The3,6-diacetyl-carbazole was synthesized from carbazole and acetyl chloride,by the reaction of acylation. Meanwhile, the substituted benzoylhydrazine were obtainvia the reaction of esterification and hydrazinolysis with the substituted benzoic acid.Then a series of novel3,6-diacetyl-carbazol-diacylhydrazone derivatives weresynthesized by the reaction of3,6-diacetyl-carbazole and substituted benzoylhydrazine.and they were characterized by1H NMR, elemental analysis, mass spectra and infraredspectra and UV-Vis spectra. The synthesis condition of target Schiff base compoundswere explored. The results show: the catalyst of the reaction was glacial acetic acid,the solvent was absolute ethanol, the temperature of the reaction was80℃, the timewas5h,and the mole ratio of the3,6-diacetyl-carbazole and benzoylhydrazinederivatives was1to2.6, the highest yield of the target Schiff base was obtained. It isthe optimum synthesis conditions.