摘要
以 13种配体分别与 10余种稀土离子形成二元配合物 ,研究其水溶液荧光强度 ,结果发现 ,只有Tb3+ 和Eu3+ 有较强荧光 ,Dy3+ 和Sm3+ 只有非常弱的荧光 ,而其他稀土离子不发光。荧光强度顺序除配体DPA为Eu3+ >Tb3+ >Dy3+ >Sm3+ 外 ,其余配体的荧光强度顺序为Tb3+ >Eu3+ >Dy3+ >Sm3+ 。以数种 4 位取代吡啶 2 ,6 二甲酸衍生物为配体 ,与Tb3+ 形成二元配合物体系 ,研究了pH、溶剂等因素对体系荧光强度的影响 ,测定了pH近中性情况下配合物体系的激发与发射光谱 ,发光寿命等 ;研究了 3或 4 位不同取代基对体系发光性能的影响。结果表明 :(1)当pH值近中性时体系的发光性能最好 ;(2 )不同取代基对体系的发光性能也有较大的影响 ,取代基为供电子基团时 ,体系的发光性能要优于取代基为吸电子基团的发光体系 ;(3 )溶剂效应的影响对体系的发光性能影响较大 ,其中低极性溶剂对体系的发光性能要优于高极性溶剂。其中 4 异丙氧基吡啶 2 ,6 二甲酸、4 乙酰氨基吡啶 2 ,6 二甲酸和 3 乙酰氨基吡啶 2 ,6 二甲酸为Tb3+ 的理想敏化剂。
Fluorescence of the substituted pyridine 2,6 dicarboxylates of RE 3+ (RE 3+ =La 3+ , Ce 3+ , Nd 3+ , Y 3+ , Er 3+ , Lu 3+ , Sm 3+ , Eu 3+ , Tb 3+ , Dy 3+ ) was analyzed. The results show that substituted pyridine 2,6 dicarboxylates can sensitize luminescence of Eu 3+ , Tb 3+ efficiently, but they sensitize Dy 3+ and Sm 3+ weakly, and do not sensitize other RE 3+ ions. The luminescence intensities of the binary complexes are sensitive to pH and solvents. The excitation, and emission spectra as well as the emission lifetimes for the binary complexes are reported. The experimental results show that the intensities of all the binary complexes are strongest in the neutral aqueous solution. In the neutral aqueous solution the fluorescence intensities of the ternary complexes enhanced and the lifetimes become longer. The luminescence of the complexes with electron donating groups is more intense than that of the complexes with electron withdrawing groups. The luminescence of the complexes in the low polar solvent is better than that in the high polar solvent. It is found that the better sensitizers for Tb(Ⅲ) are 3 (or 4) acetaminopyridine 2,6 dicarboxylic acid and isopropoxypyridine 2,6 dicarboxylic acid.
出处
《中国稀土学报》
CAS
CSCD
北大核心
2001年第6期555-560,共6页
Journal of the Chinese Society of Rare Earths
