resumo
The suitability of the computer package LUMPAC to calculate the photoluminescence properties of metal-organic frameworks was assessed by considering three systems based on the ditopic 1,4-phenylenebis(methylene)diphosphonic acid (H(4)pmd) ligand and Ln(3+) ions, namely, [Eu(Hpmd)(H2O)] (1), [La-2(H(2)pmd)(pmd)(H2O)(2)] (2) and [La-2(H(2)pmd)(3)(H2O)(12)] (3, previously reported) and their isotypical materials doped with Eu3+ cations, [(La0.95Eu0.05)(2)(H(2)pmd)(pmd)(H2O)(2)] (4) and [(La0.95Eu0.05)(2)(H(2)pmd)(3)(H2O)(12)] (5). These materials were prepared, and their structures and luminescence properties were characterized. A straightforward approximation based on the simple crystallographic structural subunits of these materials was used and resulted in an excellent agreement between the calculated and experimental properties. The intramolecular energy transfer and back-transfer rates were predicted, and the (T1D1)-D-5 channel was shown to be the dominant pathway (9.03x10(4) s(-1) for 1, 1.06x10(4) s(-1) for 4 and 2.18x10(5) s(-1) for 5).
palavras-chave
ION ENERGY-TRANSFER; COORDINATION-COMPOUNDS; DIFFERENTIAL-OVERLAP; INTERMEDIATE NEGLECT; SELECTIVE SEPARATION; THEORETICAL APPROACH; INORGANIC HYBRIDS; CONTRAST AGENTS; EUROPIUM(III); EXCHANGE
categoria
Chemistry
autores
Nolasco, MM; Mendes, RF; Lima, PP; Paz, FAA; Carlos, LD; Rocha, J
nossos autores
Filipe Alexandre Almeida Paz
Investigador Principal
João Rocha
Prof. Catedrático
Luís Carlos
Professor Catedrático
Mariela Martins Nolasco
Investigador Auxiliar
Patrícia Pereira Lima
Bolseiro de pós-Doutoramento
Ricardo Faria Mendes
Investigador JúniorGrupos
G1 - Materiais Porosos e Nanossistemas
G2 - Materiais Fotónicos, Eletrónicos e Magnéticos
G6 - Materiais Virtuais e Inteligência Artificial
agradecimentos
The authors acknowledge financial support by the Portuguese Fundacao para a Ciencia e a Tecnologia (FCT) (funding of the R&D project FCOMP-01-0124-FEDER041282, ref. FCT EXPL/CTM-NAN/0013/2013, and a Ph.D. scholarship to R. F. M., grant number SFRH/BD/84231/2012), by the European Union (EU), by the Quadro de Referencia Estrategica Nacional (QREN), by the Fundo Europeu de Desenvolvimento Regional (FEDER) - through the Programa Operacional Factores de Competitividade (COMPETE) (projects FCOMP-01-0124-FEDER-037271, ref. FCT PEst-C/CTM/LA0011/2013). QREN is further thanked for specific funding towards the purchase of the powder X-ray diffractometer and for grants to M. M. N and P. P. L. under the project CENTRO-07-ST24-FEDER-002032 (grant numbers BPD/UI96/3340/2014 and BPD/UI96/5458/2014, respectively).