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Photoluminescent Microporous Lanthanide Silicate AV‐21 Frameworks
Author(s) -
Kowalchuk Collin M.,
Paz Filipe A. A.,
Ananias Duarte,
Pattison Philip,
Carlos Luís D.,
Rocha João
Publication year - 2008
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200800172
Subject(s) - lanthanide , photoluminescence , microporous material , crystallography , materials science , silicate , hydrothermal circulation , spectroscopy , coordination number , hydrothermal synthesis , synchrotron , chemistry , chemical engineering , physics , ion , optics , optoelectronics , organic chemistry , quantum mechanics , engineering , composite material
The hydrothermal synthesis and structural characterization of the lanthanide silicate system [Na 6 Ln 2 Si 12 O 30 ⋅ x H 2 O] (Ln=La 3+ , Sm 3+ , Eu 3+ , Gd 3+ , and Tb 3+ ), named AV‐21, has been reported. Structural elucidation of the Sm 3+ analogue (isomorphous with the Eu 3+ , Gd 3+ , and Tb 3+ frameworks) using single‐crystal synchrotron X‐ray diffraction and solid‐state NMR spectroscopy reveal disorder in the Si(1) second coordination sphere. La‐AV‐21 presents a distinct framework. These materials combine microporosity and interesting photoluminescence features with structural flexibility that allows the introduction of a second or third type of lanthanide center. Room‐temperature lifetime decay dynamics have been used to estimate the Ln 3+ Ln 3+ distances and the maximum distance over which energy transfer is active. Though the majority of Ln 3+ centers occupy regular framework positions, the Ln(2) defect centers are disordered over the Na(1) sites in the pores and greatly influence the energy‐transfer process, providing a unique opportunity for studying the relationship between structural disorder and photoluminescence properties in framework solids.