酰基吡唑啉酮缩β-丙氨酸稀土配合物的合成与光谱表征

Synthesis and Spectral Characterization of Rare Earth Complexes of Acylpyrazolone-β-Alanine

在非水溶剂中,β丙氨酸与苯甲酰基吡唑啉酮反应制备出新氨基酸席夫碱试剂:1苯基3甲基4苯甲酰基吡唑啉酮5缩β丙氨酸(HL)。通过回流席夫碱与稀土硝酸盐合成了10种稀土配合物。元素分析与摩尔电导值表明新配合物的组成为[REL2NO3](nH2O(RE=La,Sm,Eu,Tb,Y,n=2;RE=Pr,Ndn=1;RE=Dy,Er,Yb,n=3)。运用红外光谱、紫外光谱、核磁共振谱和荧光光谱对配合物进行了表征。结果表明席夫碱配体以3齿形式配位,RE3+的配位数为8。在可见光区522nm;573,584nm处分别发现Er和Nd配合物的超灵敏跃迁吸收峰。配合物的荧光光谱主要体现稀土离子的ff跃迁发光,配体的发光影响较小。配合物的荧光强度:ITb>ISm>IEu>IDy。

In non-aqueous solvent, a new amino-acid schiff base, 1-phenyl-3-methyl-4-benzoyl pyrazolone-5-β-alanine （HL） was synthesized by a reaction of β-alanine with benzoylpyrazolone, and its ten rare earth complexes were obtained from refluxing a solution of schiff base and rare earth nitrates. On the basis of demental analysis and molar conductance, the general formula of the complexes,[RE2L2NO3]·nH2O （RE=La, Sin, Eu, Tb, Y, n=2; RE=Pr, Nd, n=1; RE=Dy, Er, Yb, n=3）, is given. These were characterized by IR, UV-Visible,^ 1H NMR,^ 13C NMR and fluorescence. The results show that the schiff base is a tridentate ligand, and the rare earth ions exhibit a coordination of eight in the complexes. In visible spectra, the supersensitive transitions of the Er complex at 522 nm （^4 I15/2→^2H11/2,^4S3/2 ） and that of the Nd complex at 573, 584 mn （^4I9/2→^2G7/2＋^4 G5/2 ） can be observed. Fluorescence of the complexes was produced principally by f-f transition of central ion RE^3＋ , and the ligand has little influence on lightening role. The order of relative intensity of fluorescence of the complexes is ITb 〉 ISm 〉 IEu 〉 IDy.