Please use this identifier to cite or link to this item: http://hdl.handle.net/10773/19689
Title: Chiral microporous rare-earth silico-germanates: Synthesis, structure and photoluminescence properties
Author: Ananias, Duarte
Paz, Filipe A. Almeida
Carlos, Luis D.
Rocha, Joao
Keywords: FRAMEWORK CERIUM SILICATE
ZEOLITE-TYPE MATERIALS
LANTHANIDE SILICATES
CRYSTAL-STRUCTURE
ABSOLUTE-CONFIGURATION
HYDROTHERMAL SYNTHESIS
HIGH-TEMPERATURE
ENERGY-TRANSFER
DIMENSIONALITY
RELAXIVITY
Issue Date: 2013
Publisher: ELSEVIER SCIENCE BV
Abstract: The first examples of chiral microporous rare-earth silico-germanates were obtained by isomorphous substitution of Si4+ by Ge4+ in small-pore Na-3[RESi3O9]center dot 3H(2)O (RE = Y3+, Eu3+), using hydrothermal synthesis. Single-crystal X-ray diffraction and Si-29 solid-state NMR clearly demonstrate the framework insertion of Ge4+, with preference for two of the three crystallographic T4+ sites. The isomorphous Ge4+ for Si4+ substitution originates a dispersion of the RE3+ environments, resulting in multiple and broader Eu3+ emission lines. Despite these, the main photoluminescence properties of pure Si- and Ge,Si-materials are very similar. A particularly intriguing feature is the detection, in both cases, of quasi-enantiomeric domains by selective excitation at 12 K. (C) 2012 Elsevier Inc. All rights reserved.
Peer review: yes
URI: http://hdl.handle.net/10773/19689
DOI: 10.1016/j.micromeso.2012.04.032
ISSN: 1387-1811
Publisher Version: 10.1016/j.micromeso.2012.04.032
Appears in Collections:CICECO - Artigos



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