Luminescence spectroscopy of europium(III) and terbium(III) penta-, octa- and nonanuclear clusters with β-diketonate ligands

Abstract

A series of Eu(III) and Tb(III) clusters as well as their Y(III) analogues with increasing nuclearities of 5, 8 and 9 have been synthesised using beta-diketonate ligands with decreasing steric hindrance. Their molecular structures have been established from X-ray diffraction on single crystals for most clusters and studied by luminescence and Raman spectroscopy. The Raman spectra have distinctive patterns for each nuclearity in accordance with their crystal structure. The luminescence spectra of the Eu(III) and Tb(III) clusters also show distinctive features.

Rare‐Earth Metal Oxo/Hydroxo Clusters – Synthesis, Structures, and Applications

“…The resulting nonanuclear cluster compounds are stabilized by oxo-or hydroxo groups in the inner coordination sphere and by various ligands in the outer coordination sphere (Figure 2). Examples with alkoxides, [39] -diketonates, [7,52,57,58] and pyridine derivatives [59] are known in the literature. Hydrogen atoms are omitted for clarity.…”

“…The published spectra are well resolved, also showing the other transitions, whereas the spectra of the terbium(III) cluster are less clear. [50][51][52] [Eu 5 (OH) 5 (Ph 2 acac) 10 ] was also successfully embedded into a polymer matrix by the so-called miniemulsion technique. [51] Direct miniemulsions are heterophase systems including a (polymerizable) organic phase.…”

“…[49] Since europium and terbium usually show emission in the visible region their pentanuclear clusters have been studied most intensively. [50][51][52] The europium cluster [Eu 5 (OH) 5 (Ph 2 acac) 10 ] exhibits very strong red luminescence at 612 nm, based on a 5 D 0 → 7 F 2 transition. The published spectra are well resolved, also showing the other transitions, whereas the spectra of the terbium(III) cluster are less clear.…”

Luminescent Polymeric Dispersions and Films Based on Oligonuclear Lanthanide Clusters

“…SI1a). [4,10,19,[20][21][22] In the square base face of these pyramids, four lanthanide atoms are linked by one m 4 -oxygen atom. Each lanthanide ion is coordinated by eight oxygen atoms displaying a square antiprismatic arrangement.…”

Estudo das propriedades luminescentes de íons Terras Raras em matrizes compósitas à base de alumina obtidas por pirólise de aerossol

“…Na Figura 119 é apresentado os espectros Raman para o complexo pentanuclear e para o ligante 1,3 difenil 1,3 pentanodiona (Hdbm). Diferentemente do complexo nonanuclear, o qual apresenta na região de 400 cm -1 , bandas intensas e relativamente largas com pelo menos dois máximos referentes as vibrações M-O, para o complexo pentanuclear uma única transição estreita e pouco intensa para é observada, esse perfil é compatível ao observado por Petit et al [PETIT et al, 2009]. As banda em 1598 cm -1 e 1496 cm -1 são referentes aos estiramentos simétricos e assimétricos ν(C=O) da carbonila dos grupo β-dicetona (BEYERE; YARASI; LOPPNOW, 2003;TAYYARI et al, 2007), em comparação a curva referente ao espectro do complexo estes valores são ligeiramente deslocados para valores de menor comprimento de onda 1595 cm -1 e 1490 cm -1 , este deslocamento indica a coordenação do ligante via grupos carbonílicos da β-dicetona.…”