Spectroscopic study of Tb3+(beta-diketonate)3: alpha-cyclodextrin inclusion compounds in aqueous solution

[摘要] In this work we describe how the inclusion of Tb3+ b-diketonate chelates into the hydrophobic cavity of a-cyclodextrin enhances the solubility of the complexes in aqueous medium and leads to changes in their photophysical properties. To this end, the complexes [Tb(ppa)3(H2O)2] and [Tb(ppa)3(phen)] (ppa=3-phenyl-2,4-pentanedione; phen = phenantroline) were synthesized and characterized, and they were then included into a-cyclodextrin pockets. This inclusion was confirmed by 1H NMR spectroscopy and the stoichiometry was determined by means of the Job method. In the excitation spectra, the maximum intensity wavelength of the inclusion compounds [Tb(ppa)3(H2O)2]: a-CD and [Tb(ppa)3(phen)]:a-CD were displaced 15 and 60 nm respectively when compared with the non-CD starting complexes. The typical Tb3+ emission bands were maintained after inclusion of the complexes into a-CD and their subsequent solubilization in aqueous medium.

[学科分类] 化学（综合）

[关键词] terbium(III);b-diketonate;a-cyclodextrin;inclusion compound;luminescence