Lanthanide-based thermometers: At the cutting-edge of luminescence thermometry

Present technological demands in disparate areas, such as micro and nanofluidics, micro and nanoelectronics, photonics and biomedicine, among others, have reached to a development such that conventional contact thermal probes are not accomplished to perform accurate measurements with submicrometric spatial resolution. The development of novel non-contact thermal probes is, then, mandatory, contributing for an expansionary epoch of luminescence thermometry. Luminescence thermometry based on trivalent lanthanide ions becomes very popular since 2010 due to the unique versatility, stability and narrow emission band profiles of the ions that cover the entire electromagnetic spectrum with relatively high emission quantum yields. Here we give a perspective overview on the field since the beginnings in the 1950’s until the most recent cutting-edge examples. The current movement towards the technique usage as a new tool for thermal imaging, early tumor detection and as a tool for unveil properties of the thermometers themselves or of their local neighborhoods is also summarizedpublishe

Thermal stability and thermal decomposition of the antihypertensive drug amlodipine besylate

Simultaneous thermogravimetry and differential scanning calorimetry (TG-DSC), differential scanning calorimetry (DSC) and coupled thermogravimetry coupled to infrared spectroscopy (TG-FTIR) were used to study the antihypertensive drug amlodipine besylate. The TG-DSC curves provided information concerning the thermal stability and the decomposition steps of the compound, while the DSC technique allowed us to confirm that the melting occurs concomitantly with the decomposition of the sample. By using the TG coupled to FTIR coupled techniques, it was possible to identify ammonia and methanol and CO2 as compounds released during the thermal degradation of the drug.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Intriguing light-emission features of ketoprofen-based Eu(III) adduct due to a strong electron-phonon coupling

Lanthanide-based coordination compounds of molecular formula [Ln(keto)(3)(H2O)], where Ln=Gd, Eu and keto=ketoprofen, were synthesized and their photoluminescence features were detailed in the 12-300 K interval. The emission spectra of [Eu(keto)(3)(H2O)] reveal a strong dependence with the temperature, well-illustrated by an unusual large blue-shift (similar to 17 cm(-1)) of the D-5(0)-> F-7(0) transition as the temperature is raised. The arithmetic difference between the absorption spectrum of [Eu(keto)(3)(H2O)] with that of [Gd(keto)(3)(H2O)] pointed out the presence of a ligand-to-metal charge transfer (LMCT) band (320-370 nm). From the [Gd(keto)(3)(H2O)] phosphorescence the energy of the keto-related triplet states was determined showing a large overlap with the intra-4f(6) levels and a strong electron-phonon coupling. The high-resonance between the LMCT and triplet states and the Eu3+ levels leads to a strong dependence of the D-5(0) lifetime value, typical of the presence of operative energy transfer processes. (C) 2015 Elsevier B.V. All rights reserved

Thermal and spectroscopic studies on solid ibuprofen complexes of lighter trivalent lanthanides

Solid-state compounds of general formula Ln(L)(3), in which Lis ibuprofen and Ln stands for trivalent La, Ce, Pr, Nd, Sm and Eu, have been synthesized. Simultaneous thermogravimetry and differential thermal analysis (TG-DTA), X-ray powder diffractometry (DRX), complexometry, Fourier-transformed infrared spectroscopy (FTIR) and thermogravimetry coupled to Fourier-transformed infrared spectroscopy (TG-FTIR) were used to characterize these compounds. The results provided information concerning the chemical composition, dehydration, coordination modes of the ligands, crystallinity of the samples, thermal behavior and thermal decomposition of the compounds. The theoretical and experimental spectroscopic studies suggest that ibuprofen coordinates through the carboxylate group as a chelating ligand. (C) 2013 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Study of some volatile compounds evolved from the thermal decomposition of atenolol

Simultaneous thermogravimetry-differential scanning calorimetry (TG-DSC) and coupled thermogravimetry-infrared spectroscopy (TG-FTIR) analyses were used to study the antihypertensive drug atenolol. The TG-DSC curves provided information concerning the thermal stability and decomposition profiles of the compound. From the TG-FTIR coupled techniques, it was possible to identify ammonia and isopropylamine as possible volatile compounds released during the thermal decomposition of the drug.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Synthesis, characterization and thermal behavior of solid state of some mefenamate of trivalent lanthanides (La, Ce, Pr and Nd)

Solid-state Ln(Mef)(3) compounds, where Ln stands for some trivalent lanthanides (La, Ce, Pr and Nd) and Mef is the mefenamate (C15H14NO (2) (-) ) ligand, were synthesized. The characterization and thermal and spectroscopic study of the compounds were performed using elemental analysis, complexometry, image analysis by field emission gun, simultaneous thermogravimetry and differential scanning calorimetry coupled to Fourier transform infrared spectroscopy, X-ray diffractometry, near-infrared and mid-infrared spectroscopy. All the analyses showed that the compounds were obtained in the anhydrous state. The thermoanalytical results showed that the stability and thermal behavior were markedly influenced by the atmosphere used. Moreover, the curves show that the thermal decomposition takes place in two or three steps, with the formation of lanthanide oxide (La2O3, CeO2, Pr6O11 and Nd2O3), as the final residue. Furthermore, the theoretical and experimental spectroscopic data suggested the possible modes of coordination of the ligand with the metals. The DR spectra provided information about the ligand absorption bands and the f-f transitions of Nd3+ and Pr3+ ions123191103CONSELHO 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 informaçã

Spectroscopic, luminescence and in vitro biological studies of solid ketoprofen of heavier trivalent lanthanides and yttrium(III)

Solid-state compounds of the general formulae [ML3] (M = Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y; L = ketoprofen) were synthesized and characterized using infrared, diffuse reflectance and luminescence spectroscopies. IR data suggested that the carboxylate group in ketoprofen is coordinated to the metals as a bidentate ligand. The triplet state energy level was determined using the Gd3+ complex, which exhibited a ketoprofen blue luminescence when excited in the UV region. The compound containing Tb3+ ion was sensitized by the ligand and emitted in the green region of the visible spectrum. On the other hand, for the analogous species containing the dysprosium ion, a competition for luminescence between the Dy3+ and the ligand levels was observed. Finally, Tm3+ complex exhibits only ligand luminescence. These optical behaviors are discussed based on rare earth energy diagrams. In addition, the compounds were evaluated for their anti-inflammatory activities. All the compounds showed a higher production of H2O2 and IL-10 than the ketoprofen, suggesting that the compounds exhibited an immunomodulatory effect and this opens up new perspectives for immunotherapeutic approaches. (C) 2014 Elsevier Inc. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq