A combined experimental-molecular modeling study of crown ether europium complexes: Effects of the coordinated anion on structural and luminescence properties.

Autor: da Silva Filho ASN; Programa de Pós-Graduação em Química, Universidade Federal Rural de Pernambuco, Recife, PE 52171-900, Brazil., de Souza JIR; Programa de Pós-Graduação em Ciência de Materiais, Universidade Federal de Pernambuco, 50670-901 Recife, PE, Brazil., Carolina Roma A; Departamento de Química Fundamental, Universidade Federal de Pernambuco, 50670-901, Recife, Pernambuco, Brazil., da Silva JAB; Programa de Pós-Graduação em Química, Universidade Federal Rural de Pernambuco, Recife, PE 52171-900, Brazil; Núcleo Interdisciplinar de Ciências Exatas e da Natureza, CAA, Universidade Federal de Pernambuco, Nova Caruaru, Caruaru, PE 55.014-900, Brazil., Longo RL; Programa de Pós-Graduação em Ciência de Materiais, Universidade Federal de Pernambuco, 50670-901 Recife, PE, Brazil; Departamento de Química Fundamental, Universidade Federal de Pernambuco, 50670-901, Recife, Pernambuco, Brazil., Alves S Jr; Programa de Pós-Graduação em Ciência de Materiais, Universidade Federal de Pernambuco, 50670-901 Recife, PE, Brazil; Departamento de Química Fundamental, Universidade Federal de Pernambuco, 50670-901, Recife, Pernambuco, Brazil., Belian MF; Programa de Pós-Graduação em Química, Universidade Federal Rural de Pernambuco, Recife, PE 52171-900, Brazil; Departamento de Química, Universidade Federal Rural de Pernambuco, 52171-900 Recife, Pernambuco, Brazil. Electronic address: monica.freirebelian@ufrpe.br.
Jazyk: angličtina
Zdroj: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy [Spectrochim Acta A Mol Biomol Spectrosc] 2024 Mar 05; Vol. 308, pp. 123704. Date of Electronic Publication: 2023 Dec 02.
DOI: 10.1016/j.saa.2023.123704
Abstrakt: It is reported the synthesis, characterization by elemental analysis, thermogravimetry; electronic absorption, infrared, excitation, and emission spectroscopies of the [Eu(12C4)(phen) 2 (X) n ]X 2 complexes, where 12C4 = 12-crown-4, phen = 1,10-phenanthroline, and X  = F - , Cl - , Br - , SCN - , ClO 4 - , and NO 3 - . It is verified that the polarizability of the anion X - exerts remarkable effects on the emission process. As a general trend, lower wavenumbers for the 7 F 0 → 5 L 6 , 7 F 0 → 5 D 2 and 7 F 0 → 5 D 1 transitions are associated with the anions with higher volumes and, consequently, higher polarizability. The molecular modeling results performed with quantum methods (RHF and DFT) suggest some relationships between the calculated structures, electronic, and luminescence properties with the presence of the LMCT (ligand-to-metal charge transfer) states, which explains the differences in the emission spectra of these complexes due to the coordinated anion.
Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Monica Freire Belian reports financial support was provided by Federal Rural University of Pernambuco. Monica Freire Belian reports a relationship with Federal Rural University of Pernambuco that includes: employment.
(Copyright © 2023 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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