A dual channel naphthyl-BODIPY probe for the detection of cations in mixed aqueous solution

The development of chemosensors for the sensing of metal ions is one of the most active research fields with great potential for environmental, physiological and medicinal applications, especially in the case of Pd2+, Hg2+ and the trivalent cations Fe3+ and Al3+. For example, mercury is one of the most toxic metal ions, even at very low concentrations. Accumulation of mercury over time in humans leads to cognitive and motion disorders and Minamata disease. On the other hand, trivalent metal cations such as Fe3+ and Al3+ play crucial roles in physiological processes and its abnormal levels in human tissues and cells could induce anemia, diabetes, Alzheimer´s and Parkinson’s diseases. Therefore, the efficient detection of these cations is a timeless topic in several areas of investigation. We report herein the chromo-fluorogenic behavior toward metal cations of a new BODIPY probe bearing a 4-N,N-dimethylnaphthyl group attached to the meso position of the BODIPY core and a formyl group in position 2. This receptor is a dual channel probe that can be used for the chromogenic and fluorogenic detection, in mixed aqueous solutions, of trivalent (Fe3+and Al3+) and divalent cations (Hg2+and Pd2+) with biological and medicinal relevance.The authors acknowledge Fundação para a Ciência e Tecnologia (Portugal) for funding through CQUM (Pest-C/QUI/UI0686/2019) and project PTDC/QUI COL/28052/2017. The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network (REDE/1517/RMN/2005)

Functionalized BODIPY derivatives as potential fluorescent labels

BODIPY derivatives 1 and 2 were obtained with 16 % and 33 % yield by a two-step reaction: condensation of a pyrrole with the corresponding aldehyde followed by oxidation with DDQ in the presence of BF3OEt2. The two compounds were characterized by the usual spectroscopic techniques and a detailed photophysical study was undertaken. The compounds exhibited intense absorption bands at 502 nm and 497 nm, respectively. Emission studies of the compounds 1 and 2 showed emission bands with maximum wavelength at 518 nm and 519 nm, respectively.Thank are due to Fundação para a Ciência e Tecnologia (Portugal) and FEDER-COMPETE for financial support through Centro de Química (UID/QUI/0686/2016). The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network and was purchased within the framework of the National Program for Scientific Re-equipment, contract REDE/1517/RMN/2005 with funds from POCI 2010 (FEDER) and FCT.info:eu-repo/semantics/publishedVersio

Anion dual mode fluoro-chromogenic chemosensor based on a BODIPY core

Herein, we report the synthesis and chromo-fluorogenic behaviour of a BODIPY derivative. The BODIPY core was functionalized with a phenyl group at meso-position and a formyl group at 2-postion introduced through the Vilsmeier Haack reaction. The compound showed an absorption band at 492 nm and an emission band at 508 nm, with a ФF = 0.84. The evaluation of the chemosensing ability of the BODIPY was investigated in the presence of several anions with environmental and biomedical relevance and a simultaneous colorimetric and fluorimetric response was observed for cyanide and fluoride anions.The authors acknowledge Fundação para a Ciência e Tecnologia—FCT (Portugal) for funding through CQUM (UID/QUI/00686/2020) and a Ph.D. grant to. R. C. R. Gonçalves (SFRH/BD/05278/2020). The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network and was purchased within the framework of the National Program for Scientific Re-equipment, contract REDE/1517/RMN/2005 with funds from POCI 2010 (FEDER) and FCT

Methodology for the characterization of elastic constants of wood from tree branches

In biomechanical analyses, computational models are essential tools for simulating the behavior of a tree subjected to a load. However, such models allow only approximation of the actual behavior of the tree if the elastic parameters of the wood in different tree parts (stem, branches, and roots) and at least orthotropic behavior are not considered. In addition, as the wood is green, the parameters of strength and stiffness must be adequate for this level of moisture. However, even for stem wood, knowledge of elastic properties is not available for most species used in urban tree planting, and this scarcity of information is even greater for wood branches. The objective of this research was to evaluate methodology, based on wave propagation, in characterizing the 12 elastic constants of wood from branches. Complementarily, compression tests were performed to characterize the strength. The obtained elastic parameters using ultrasound tests were comparable with the values expected based on theoretical aspects related to the behavior of the wood. The results of the compression test complemented the ultrasound characterization, but the application of this method for the complete characterization of the elastic parameters is not feasible for tree branches because of their small size.1448439845

Anion Colorimetric Chemosensor Based on a Benzimidazole-Functionalized BODIPY Derivative

A BODIPY derivative bearing a benzimidazole unit at position 2 and an electron donor group (anthracene) at the meso position was synthetized and characterized by the usual spectroscopic techniques. The evaluation of the compound as a colorimetric chemosensor was performed in solutions of acetonitrile/water (75:25) in the presence of several anions (HSO4−, NO3−, H2PO4−, CN−, BzO−, ClO4−, Br−, F−, I− and CH3CO2−) with biomedical and environmental relevance. The in-vestigated BODIPY derivative demonstrated a selective color change from pink to yellow upon interaction with a hydrogen sulfate anion (HSO4−).The authors acknowledge Fundação para a Ciência e Tecnologia-FCT (Portugal) for funding through CQUM (UID/QUI/00686/2020) and project PTDC/QUI-COL/28052/2017 and a PhD grant to. R. C. R. Gonçalves (SFRH/BD/05278/2020). The NMR spectrometer Bruker Avance III 400 was part of the National NMR Network and was purchased within the framework of the National Program for Scientific Re-equipment, contract REDE/1517/RMN/2005, with funds from POCI 2010 (FEDER) and FCT

Synthesis, characterization and evaluation of a carbazolyl-BODIPY as a fluorimetric chemosensor for F-

BODIPY dyes have received great attention in the last few years as optical chemosensors since they can recognize metal ions in solutions through optical signals (colorimetric and/or fluorimetric). In this context, our research group reports the synthesis of a carbazolyl-BODIPY derivative and its respective characterization by 1H NMR spectroscopy and mass spectrometry. Furthermore, a preliminary study of the chemosensory capacity of this BODIPY derivative was carried out in acetonitrile solution in the presence of several anions and a highly selective fluorimetric response was obtained for F-

A meso-triphenylamine-BODIPY derivative for the optical chemosensing of metal ions

The design and synthesis of organic molecules for recognition of biologically/environmentally important metal ions has emerged as a highly regarded research field. The BODIPY (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) core is a versatile signaling molecule that can be fine-tuned with functional groups to create selective binding sites to improve its optical proper-ties. As an extension of the work developed in our research group, we report the synthesis and characterization of a BODIPY functionalized with triphenylamino and a formyl group at the meso and 2-position, respectively, for the highly selective detection of Cu2+ and Fe3+. The preliminary study of the BODIPY derivative as optical chemosensor was carried out in acetonitrile solution in the presence of different cations, and interactions with Cu2+ and Fe3+ induced a perceptible color change. UV-visible titrations showed changes in the absorption spectra upon the addition of three equivalents of each cation, with the appearance of a new absorption band at 693 nm.This research was funded by Foundation for Science and Technology (FCT) for financial support to CQ/UM (UID/QUI/00686/2020) and project PTDC/QUI-COL/28052/2017. Thanks are also due to Fundação para a Ciência e Tecnologia (Portugal) for financial support to the Portuguese NMR network (PTNMR, Bruker Avance III 400-Univ. Minho)