杯[8]芳烃-硝酸稀土配合物的红外光谱及荧光性能

合成了以对叔丁基杯[8]芳烃(LH₈)、硝酸根及DMF为配体,单一稀土RE³⁺(Sm³⁺、Eu³⁺、Tb³⁺、Dy³⁺)及混合稀土Tb³⁺:Ln³⁺(Ln=La³⁺,Gd³⁺,Y³⁺)为中心的7种稀土配合物,对其进行了元素分析、摩尔电导、热谱、红外光谱及荧光性能研究.荧光光谱的测试表明所有Tb³⁺及其共掺杂配合物具有较强的特征荧光发射,荧光惰性离子La³⁺、Gd³⁺、Y³⁺对Tb³⁺的荧光有增强作用,其中Y³⁺的荧光增强作用最大,Gd³⁺次之,La³⁺最小.

Infrared Spectra and Luminescent Properties of p-tert-Butylcalix [8] arene-DMF Complexes of Rare Earth Nitrates

Seven solid p-tert-butylcalix [8] arene(LH₈)-DMF coordination compounds of rare earth(Sm³⁺,Eu³⁺,Tb³⁺,Dy³⁺)and Tb³⁺ nitrates doped with Ln³⁺(La³⁺,Gd³⁺,Y³⁺)have been synthesized.Their elemental analysis,rare earth complexometric titration,molar conductive,IR spectra,UV spectra and TG-DTA have been studied.The results suggest that the composition of the complexes are [RE(LH₆)(NO₃)(DMF)₄]-3DMF and [Ln_0.5Tb_0.5(LH₆)(NO₃)(DMF)₄]3DMF,respectively.In these complexes,the rare earth ions coordinate to the oxygen atoms of p-tert-butylcalix[8]arene(LH₈)and DMF,NO^-₃ group coordinate to the rare earth ions as the bidentate form.The fluorescence spectra of the complexes are determined at room temperature.The results suggest that the fluorescence emission intensity data are very different for the complexes,the data of terbium complex is higher,but other complexes are weaker.The fluorescence intensity of terbium complex is determined by the optimum excitation wavelength 322 nm(the exbandpass and embandpass are all 3 nm).As seen from Fig.2,terbium complex and its doped with La³⁺,Gd³⁺and Y³⁺complexes have characteristic luminescence and its fluorescence intensity is enhanced after doping with La³⁺,Gd³⁺,Y³⁺.These show that the lowest excitation state energy level of Tb³⁺ ion with the triplet state energy level of the ligands match well each other.The absorbing energy of the ligands are effectively transferred to Tb³⁺ ion.The energy transferred process may be(LH₆)^2-→[(LH₆)^2-]^* Ln³⁺→[(LH₆)^2-]^* Tb³⁺→⁵D₄(Tb³⁺)(Ln=La,Gd,Y).The fluorescence intensity of terbium complex is enhanced after doping with La³⁺,Gd³⁺,and Y³⁺ ions.The radius of Y³⁺ is the smallest,Gd³⁺ is middle,and La³⁺ is the biggest,so their coordination compounds.The distance is the shortest of Y³⁺ coordination compound with Tb³⁺ coordination compound,Gd³⁺coordination compound is middle,and La³⁺ coordination compound is the longest,for this reason,the sensitization actions from La³⁺,Gd³⁺,and Y³⁺ to Tb³⁺ ion are Y³⁺>Gd³⁺>La³⁺.