Nanothermometer based on intensity variation and emission lifetime of europium(III) benzoylacetonate complex

Temperature dependence of the photophysical properties of europium(III) complex with the benzoylcetonate ligand were evaluated. The photostability of the complex and the temperature dependence of the 5D0 → 7F2 transition band area (maximum relative sensitivity of 5.25% K−1 at 303 K) makes this complex promising as temperature probe. The temperature dependence of the 5D0 → 7F0 transition band indicates that the electron-phonon coupling is probably the main mechanism operating in the temperature dependence of the photophysical properties of the complex.192224230CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPSem informaçãoSem informação2013/22127-

A zero-field single-molecule magnet with luminescence thermometry capabilities containing soft donors

Simultaneous fine-tune of magnetic and optical properties in lanthanide single-molecule magnets (SMMs) is a daunting task. Even more so when additional functionalities, like luminescence thermometry, are sought after. Herein, we explore the use of a ligand with both soft and hard donor atoms (thiobenzoate, tba−) as a strategy to prepare a multifunctional optomagnetic lanthanide complex. The proposed mononuclear Dy3+ complex acts as a zero-field SMM, whose energy barrier to magnetization reversal was confirmed from the analysis of the photoluminescence spectrum. Moreover, the temperature dependence of the emission spectral profile was harnessed to build a thermometric approach working below 12 K - where the complex behaves as an SMM. In search for general trends informing the preparation of similar multifunctional SMMs, we modelled the electronic properties of a series of complexes where the sulfur atom of tba− is replaced for other chalcogens (O, Se, Te). These calculations show that careful choice of ligands with soft donor atoms can boost both magnetic and thermometric performances, paving the way for the rational design of novel multifunctional lanthanide complexes.publishe

Thermal behavior, spectroscopic studies and free radical scavenging potential of some mefenamate trivalent lanthanides (Sm, Eu, Gd, Tb and Dy)

Lanthanide Mefenamate compounds were prepared in solid state. TG-DSC coupled to FTIR, elemental analysis, complexometry with EDTA, X-ray powder diffractometry, evaluation of scavenging free radical activity with DPPH (2,2-diphenyl-1-picryl-hydrazine), and a complete spectroscopic study in the ultraviolet, visible, near-, and middle-infrared regions were realized to obtain some physicochemical properties of the synthesized compounds. The thermal stability, minimum formula, thermal behavior and intermediate compounds were indicated by thermoanalytical results. Furthermore, vibrational spectroscopy data suggests that the complexes are binuclear and two modes of coordination are presented. The DR spectra could be reveal the presence of a large ligand-to-metal charge transfer band in the europium mefenamate. This compound also indicated the higher antioxidant activity with DPPH (77.03% at 200 μg L−1).6517382CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPSem informaçãoSem informaçãoSem informaçã

Thermal Behavior, Spectroscopic Studies And Free Radical Scavenging Potential Of Some Mefenamate Trivalent Lanthanides (sm, Eu, Gd, Tb And Dy)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Lanthanide Mefenamate compounds were prepared in solid state. TG-DSC coupled to FTIR, elemental analysis, complexometry with EDTA, X-ray powder diffractometry, evaluation of scavenging free radical activity with DPPH (2,2-diphenyl-1-picryl-hydrazine), and a complete spectroscopic study in the ultraviolet, visible, near-, and middle-infrared regions were realized to obtain some physicochemical properties of the synthesized compounds. The thermal stability, minimum formula, thermal behavior and intermediate compounds were indicated by thermoanalytical results. Furthermore, vibrational spectroscopy data suggests that the complexes are binuclear and two modes of coordination are presented. The DR spectra could be reveal the presence of a large ligand-to-metal charge transfer band in the europium mefenamate. This compound also indicated the higher antioxidant activity with DPPH (77.03% at 200 μg L−1). © 2017 Elsevier B.V.6517382CAPES, Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorCNPq, Conselho Nacional de Desenvolvimento Científico e TecnológicoFAPESP, Fundação de Amparo à Pesquisa do Estado de São PauloCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP