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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Eu3+- and Tb3+-Dipicolinate Complexes Covalently Grafted into Kaolinite as Luminescence-Functionalized Clay Hybrid Materials

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Author(s):
de Araujo, Denis Talarico ; Ciuffi, Katia J. ; Nassar, Eduardo J. ; Vicente, Miguel A. ; Trujillano, Raquel ; Calefi, Paulo S. ; Rives, Vicente ; de Faria, Emerson H.
Total Authors: 8
Document type: Journal article
Source: Journal of Physical Chemistry C; v. 121, n. 9, p. 5081-5088, MAR 9 2017.
Web of Science Citations: 3
Abstract

The luminescence properties of Eu3+- and Tb3+-dipicolinate (pyridine- dicarboxylate) complexes covalently grafted into a kaolinite matrix were studied. The stability of the grafted lanthanide complexes as a function of the thermal treatment was also investigated. Kaolinite intercalated with dimethyl sulfoxide was heated in the presence of melted dipicolinic acid to form dipicolinate-intercalated kaolinite. The luminescent hybrid solids were obtained by complexation of Eu3+ or Tb3+ cations with this intercalated solid at cation/ligand molar ratios of 1:1, 1:2, or 1:3. The resulting materials were characterized by thermal analysis, CHN element analysis, powder X-ray diffraction, infrared absorption spectroscopy, and photoluminescence. The lanthanide complexes covalently grafted into kaolinite were thermally more stable than the isolated lanthanide complexes. The hybrid materials exhibited more intense Eu3+ and Tb3+ emissions than the isolated complexes. The excitation spectra of the hybrid materials showed a broad band at 277 nm, assigned to a ligand-to-metal charge transfer, whereas the emission spectra showed bands related to the typical electronic transitions of Eu3+ and Tb3+ ions from the excited states D-5(0) and D-5(4) to the F-7(j) fundamental states. The (4 -> 5 and 4 -> 4) and (0 -> 2) transitions were the most intense ones and corresponded to green and red emissions, respectively. (AU)

FAPESP's process: 13/50216-0 - New clay-based materials with advanced technological and environmental applications
Grantee:Katia Jorge Ciuffi Pires
Support Opportunities: Regular Research Grants
FAPESP's process: 16/01501-1 - Multifunctional catalysts for advanced oxidation processes employing biogenic matrices or clays
Grantee:Katia Jorge Ciuffi Pires
Support Opportunities: Regular Research Grants
FAPESP's process: 13/19523-3 - Functional Biohybrid materials based on layered and/or fibrous natural clays with multifaceted applications
Grantee:Emerson Henrique de Faria
Support Opportunities: Regular Research Grants