Molecule-Like Eu3+-Dimers Embedded in an Extended System Exhibit Unique Photoluminescence Properties
authors Ananias, D; Kostova, M; Paz, FAA; Neto, ANC; De Moura, RT; Malta, OL; Carlos, LD; Rocha, J
nationality International
journal JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
keywords MICROPOROUS LANTHANIDE SILICATES; RARE-EARTH IONS; ENERGY-TRANSFER; TRANSITIONS; SPECTRA; LIGHT; CONDUCTIVITY; LUMINESCENCE; INTENSITIES; FIELD
abstract Much is known about the photoluminescence of lanthanide-containing systems, particularly amorphous silicates or organic-inorganic hybrids and crystalline metal-organic frameworks. Comparatively, stoichiometric microporous Ln-silicates are poorly studied. Here, we report the exceptional photoluminescence of microporous AV-24, K-7[Ln(3)Si(12)O(32))center dot xH(2)O (Ln(3+) = Sm3+, Eu3+, Gd3+, Tb3+), the first silicate possessing Ln(3+)-O-Ln(3+) dimers (inter-Ln distance ca. 3.9 angstrom), i.e., two edge-sharing {LnO(6)} octahedra embedded in a crystalline matrix. It is totally unprecedented that in AV-24 Eu3+-O-Eu3+ dimers behave like discrete entities, i.e., molecules: they (i) have a unique emission signature, with pseudopoint group symmetry (C-i), different from the symmetry (C-1) of each individual constituent Eu3+ ion, and (ii) exhibit the unusually long D-5(0) lifetime of 10.29 ms (12 K). In accord with the experimental evidence, a molecular orbital model shows that the Eu3+-O-Eu3+ dimers are energetically more stable than the individual metal ions.
publisher AMER CHEMICAL SOC
issn 0002-7863
year published 2009
volume 131
issue 24
beginning page 8620
ending page 8626
digital object identifier (doi) 10.1021/ja901820z
web of science category Chemistry, Multidisciplinary
subject category Chemistry
unique article identifier WOS:000267630000060
  ciceco authors
  impact metrics
journal analysis (jcr 2019):
journal impact factor 14.612
5 year journal impact factor 14.549
category normalized journal impact factor percentile 92.938
dimensions (citation analysis):
altmetrics (social interaction):



 


Sponsors

1suponsers_list_ciceco.jpg