四硝基酚臂式氮杂18-冠-6与稀土离子配位性能的研究  

Studies on Rare Earth Ions Complexation Properties of Tetranitrophenols-Armed Aza-18-Crown-6

作　　者：张强[1] 高生华[1] 

机构地区：[1]内蒙古师范大学化学与环境科学学院,内蒙古呼和浩特010022

出　　处：《光谱学与光谱分析》2008年第12期2904-2907,共4页Spectroscopy and Spectral Analysis

基　　金：内蒙古自然科学基金项目(200508010212;200607010207)资助

摘　　要：合成并表征了1,10-二氧-4,7,13,16-四氮杂18-冠-6(L1)母体及其硝基酚臂式衍生物(L2)。在H2O-DMSO(φ=1/4)混合溶剂中用UV-Vis光谱法对L2与H+,Ce3+,Nd3+,Sm3+,Eu3+,Gd3+,Tb3+,Dy3+和Yb3+离子的相互作用进行了研究,并测定了配位稳定常数。结果表明,当溶液中pH值由1.85逐渐增大时,冠醚L2的吸收峰位从314 nm处红移;pH值增大到7.4时,在400 nm处产生了新的吸收峰,并且其峰位波长和峰强度随溶液碱性增强逐渐增大。当溶液中同时有稀土离子存在时,L2在400 nm以上的吸收峰相对于L2单独存在时发生紫移,且强度显著增大,证明了稀土配合物的形成,并且形成的pH值条件约大于7.0。L2与稀土离子的配位稳定常数值表明,其配位稳定性决定于冠醚空穴尺寸与稀土离子大小的匹配程度,随着Ce3+,Nd3+,Sm3+,Eu3+,Gd3+,Tb3+,Dy3+和Yb3+离子半径的依次减小,其配合物的稳定性趋于降低。The synthesis of macrocyclic ligands appended with fluorescent or chromogenic chelators is a promising approach to developing metal-ion chemosensors because of the ion selectivity of macrocyclic ligands and the fluorescence or chromogenic response of the appended chelating groups.In the present paper,1,10-dioxa-4,7,13,16-tetraaza-18-crown-6（L1） and 4,7,13,16-tetra（2-hydroxy-5-nitrobenzyl）-1,10-dioxa-4,7,13,16-tetraaza-18-crown-6（L2） were synthesized and characterized via elemental analysis and 1H NMR spectrum.The complexation properties of L2 for H^＋,Ce^3＋,Nd^3＋,Sm^3＋,Eu^3＋,Gd^3＋,Tb^3＋,Dy^3＋ and Yb^3＋ were studies by UV-Vis method in H2O-DMSO（φ=1/4） mixed solvent,and the stability constants of the complexes were determined.The results obtained indicate that the absorption peak of azacrown ether L2 at 314 nm was shifted toward long wavelength with increasing pH from 1.85 in the investigated solution.A new absorption peak appeared at 400 nm while increasing pH to 7.4,and the wavelength of peak position and absorption intensity were increased gradually with increasing pH.When rare earth ions were added to the solution,the absorption peak of L2 above 400 nm was shifted toward short wavelength,and absorption intensity was increased obviously in comparison with L2 alone.Thus the formation of the complex was verified,and it was formed at pH〉7.0.The stability constants of the complexes obtained show that stability of the complexes depends upon the match between cavity dimension of L2 and size of the rare earth ions.There was a decrease in stability of complex with decreasing the radius of rare earth ion in the order of Ce^3＋〉Nd^3＋〉Sm^3＋〉Eu^3＋〉Gd^3＋〉Tb^3＋〉Dy^3＋〉Yb^3＋.

关 键 词：四硝基酚臂式氮杂18-冠-6 合成 稀土离子 紫外可见光谱法 配位性能 

分 类 号：O621.2[理学—有机化学]