부산대학교 도서관

The synthesis and spectroscopic study of the Eu(hfc)3·2H2O complex (hfc: 4,4,4-trifluoro-butyryl (+) canfore) with bipyridinedioxide (bipyO2) is described. The coordination of bipyO2 to the Eu(III) ion in the complex is evidenced due to the presence of a strong band at 1241 cm-1 shifted from 1252 cm-1 in the bipyO2 spectrum and attributed to the stretch of its N-oxide group. The complex Eu(hfc)3·bipyO2 (hfc: 6,6,7,7,8,8,8-heptafluoro-2,2′-dimethyl 1,3,5-hydroxymethyllene (+) canfore) has a lifetime of 652 μs which is higher than that of the Eu(hfc)3·2H2O complex as well as that of the similar complex with β-diketone with CF3 group. This lifetime value confirms that the Eu(III) luminescence in the complex Eu(hfc)3·bipyO2 is stronger than in both complexes above cited. The geometry of this complex has been previously optimized using the sparkle model and the results have been used to perform theoretical predictions of the Judd–Ofelt intensity parameters Ωλ (λ=2.4) using the simple overlap model (SOM) and correlated to experimental data obtained by means of the emission spectra. The experimental value of the area of the 5D0→7F2 transition is 20 times larger than that of the 5D0→7F1 transition. This reflects the hypersensitivity of the 5D0→7F2 transition. A good agreement between theoretical and experimental UV absorption spectra of the complex has been obtained. This result increased our confidence in the predicted structure. [Copyright &y& Elsevier]