The synthesis of a Co metal-organic framework assembled from 5,10,15,20-tetrakis((pyridin-4-yl)phenyl)porphyrin; TPhPyP) "Co-MTPhPyP" is reported. The TPhPyP ligand was synthesized via aldehyde ...condensation in 28% yield and characterized by
H nuclear magnetic resonance (
H NMR), Fourier-transform infrared (FTIR), high-resolution mass spectrometry (HRMS), and UV-visible spectroscopy (UV-vis). Co-MTPhPyP was prepared by the solvothermal method from TPhPyP and CoCl
·H
O in 55% yield and characterized by X-ray powder diffraction (XRD), FTIR, thermogravimetric analysis (TGA), field-emission scanning electron microscopy with energy-dispersive X-ray (FESEM-EDS), X-ray photoelectron spectroscopy (XPS), and dynamic light scattering (DLS), showing a particle size distribution of 418 ± 58 nm. The sorption properties of the Co-MTPhPyP for the effective removal of Pb(II) and Cu(II) were evaluated in an aqueous medium and Cthe results showed uptake capacities of 383.4 and 168 mg of the metal g
after 2 h, respectively. Kinetic studies of Pb(II) adsorption by Co-MTPhPyP were adjusted to the pseudo-second-order model with a maximum adsorption capacity of 458.8 mg g
at 30 min of exposition.
Seven new pyrrolo3,4-bpyridin-5-ones linked to a meso-thienyl BODIPY moiety by an ethynylbenzene π-conjugated system were synthesized in one-pot manner via an Ugi-Zhu reaction coupled to a cascade ...process aza Diels-Alder cycloaddition/N-acylation/decarboxylation/dehydration. The photophysical properties of the polyheterocyclic compounds were evaluated by UV–Vis and fluorescence spectroscopy in five solvents of different polarities. All synthesized products showed two distinct absorption/emission bands, corresponding to both fluorophores separately. The fluorescence intensity of the pyrrolo3,4-bpyridin-5-one was the highest in toluene, and it decreased with increasing solvent polarity. On the other hand, the fluorescence intensity of the meso-thienyl BODIPY fragment was insensitive to solvent polarity. The effect of different substituents bonded to the pyrrole ring was evaluated, finding that strong electron-donating groups influence the fluorescence intensity and decay rate of the compounds, even with the presence of a methylene spacer. Moreover, the electronic structure was assessed by DFT and TD-DFT calculations, which reproduced the experimental results reasonably well, showing that the HOMO is located on the pyrrolo3,4-bpyridin-5-one core, while the LUMO is on the BODIPY fragment.
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The synthesis of a Co metal–organic framework assembled from 5,10,15,20-tetrakis((pyridin-4-yl)phenyl)porphyrin; TPhPyP) “Co-MTPhPyP” is reported. The TPhPyP ligand was synthesized via aldehyde ...condensation in 28% yield and characterized by sup.1H nuclear magnetic resonance (sup.1H NMR), Fourier-transform infrared (FTIR), high-resolution mass spectrometry (HRMS), and UV-visible spectroscopy (UV-vis). Co-MTPhPyP was prepared by the solvothermal method from TPhPyP and CoClsub.2·Hsub.2O in 55% yield and characterized by X-ray powder diffraction (XRD), FTIR, thermogravimetric analysis (TGA), field-emission scanning electron microscopy with energy-dispersive X-ray (FESEM-EDS), X-ray photoelectron spectroscopy (XPS), and dynamic light scattering (DLS), showing a particle size distribution of 418 ± 58 nm. The sorption properties of the Co-MTPhPyP for the effective removal of Pb(II) and Cu(II) were evaluated in an aqueous medium and Cthe results showed uptake capacities of 383.4 and 168 mg of the metal gsup.−1 after 2 h, respectively. Kinetic studies of Pb(II) adsorption by Co-MTPhPyP were adjusted to the pseudo-second-order model with a maximum adsorption capacity of 458.8 mg gsup.−1 at 30 min of exposition.
The electrochemical reduction mechanisms of diprotonated tetraphenylporphyrin (H2TPP) and mono- and diprotonated octaethylporphyrin (H2OEP) were studied in tetrabutylammonium ...perchlorate/benzonitrile. The diprotonated forms of both porphyrins undergo two one-electron reversible reduction processes forming isophlorin. Contrastingly, monoprotonated H2OEP is reduced in a single process involving a two-electron one-proton transfer that yields two types of short-lived intermediates, isophlorin and neutral phlorin. The existence of intermolecular proton transfer reactions, from the parent protonated porphyrin to the isophlorin or neutral phlorin, to form phlorin cation species (isophlorin protonated at the meso-position) was demonstrated. In-situ UV-vis spectroelectrochemical experiments allowed us to identify the absorption of the isophlorin species of H2TPP but not of H2OEP. These results show that the lack of phenyl substituents increases the rate of protonation at the meso-position. Finally, it was demonstrated that the protonation of the porphyrin macrocycle not only lowers the reduction potentials but also increases the reactivity of the electrogenerated species.
A series of novel fluorescent BODIPY-anionic boron cluster conjugates bearing B
H
(5, 6), 3,3'-Co(1,2-C
B
H
)
(7, 8), and 3,3'-Fe(1,2-C
B
H
)
(9) anions have been readily synthesized from ...meso-(4-hydroxyphenyl)-4,4-difluoro-4-bora-3 a,4 a-diaza- s-indacene (BODIPY 4), and their structure and photoluminescence properties have been assessed. Linking anionic boron clusters to the BODIPY (4) does not alter significantly the luminescent properties of the final fluorophores, showing all of them similar emission fluorescent quantum yields (3-6%). Moreover, the cytotoxicity and cellular uptake of compounds 5-9 have been analyzed in vitro at different concentrations of B (5, 50, and 100 μg B/mL) using HeLa cells. At the lowest concentration, none of the compounds shows cytotoxicity and they are successfully internalized by the cells, especially compounds 7 and 8, which exhibit a strong cytoplasmic stain indicating an excellent internalization efficiency. To the best of our knowledge, these are the first BODIPY-anionic boron cluster conjugates developed as fluorescent dyes aiming at prospective biomedical applications. Furthermore, the cellular permeability of the starting BODIPY (4) was improved after the functionalization with boron clusters. The exceptional cellular uptake and intracellular boron release, together with the fluorescent and biocompatibility properties, make compounds 7 and 8 good candidates for in vitro cell tracking.
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•Organic cationic tracers for heterogeneity characterization in carbonate reservoir.•Unreported MW synthesis to obtain an environmentally friendly family of tracers.•Selection ...criteria: aging and adsorption test under reservoir-emulating conditions.•Developed tracer does not alter the water-oil-rock interactions.•Good performance in porous media under reservoir-emulating conditions.
Tracers are practical tools to provide insight on reservoir heterogeneity. However, scarce is the variety of available alternatives designed specifically for carbonate oil reservoir. Through application-oriented design, directed ad hoc to carbonate oil reservoirs, a family of cationic fluorinated tracers was developed, aided by computational design. This was done through the microwave assisted, one-step synthesis of fluorinated anilines exhaustively methylated in mild reaction conditions. Stability and aging tests were carried out at reservoir-emulating conditions, confirming the structural integrity of the compounds through 19F NMR and UHPLC-MS. Moreover, the developed tracer showed low adsorption compared to a commercial anionic tracer and did not modify the water-oil-rock physical and interfacial properties, remaining preferably partitioned towards water. Finally, degree of heterogeneity characterization in a packed column of natural mineral rock was obtained with the developed tracer, and its commercially available anionic analogue commonly used in field tracer tests. The comparison showed the potential of developed tracers as prominent candidates to support the design of exploitation processes, environmentally friendly and nontoxic, in carbonate oil reservoirs.
The electrochemical reduction of two meso-substituted dipyrrometheneboron difluorides, BODIPYs, 8-(thiophen-2-yl)-dipyrrometheneboron difluoride and 8-(phenyl)-dipyrrometheneboron difluoride, was ...studied in acetonitrile. Both compounds underwent two consecutive electron transfers to produce the radical anion and dianion species. The cyclic voltammograms show that the current intensity of the second cathodic peak is much smaller than the first one-electron reduction process. The current intensity ratio of the two peaks (iIIc/iIc) was analyzed as a function of the BODIPY concentration and of the scan rate; the results indicate that dimerization reactions are responsible for the remarkable current decrease in the second electroreduction. Digital simulations of the experimental cyclic voltammograms show that the three possible dimerization reactions, radical anion-radical anion, radical anion-dianion and neutral-dianion, have a different effect on the voltammetric behavior. Thus, the simulation analysis allowed to elucidate the reaction mechanism.
Two crystalline
meso
-substituted BODIPYs were investigated as supramolecular building blocks of Langmuir–Blodgett (LB) thin films. These sorts of thin films are formed by the transfer of a Langmuir ...monolayer film of organized amphiphilic molecules onto a solid substrate. In the present contribution, we exploited the capacity of the featured BODIPYs to produce ordered supramolecular self-assemblies through hydrogen-bonding and π-stacking to pre-organize and to control their assembly as LB thin films. Electronic absorption and fluorescence emission of the
meso
-substituted BODIPYs in solution, LB films, and in solid state were studied. The morphology and structure of the LB films were examined by scanning electron microscopy and atomic force microscopy. The structural differences between both BODIPYs have no marked influence on the absorption and fluorescence emission properties in solution. In contrast, absorption properties in solid state (solid samples and LB thin films) depend on the structural nature of the dyes with the appearance of red-shifted bands, which could be an indicator of the presence of aggregates. The supramolecular information contained in the BODIPYs was reflected on the surface characteristics of the featured LB thin films. Both produced homogeneous and uniform films with the presence of some microcrystals, as the number of transferred monolayers increased. These results broaden the capacity of the Langmuir–Blodgett technique to produce ordered and self-assembled thin films of functional small organic molecules (such as BODIPYs) as components of different optoelectronic devices.
Graphic abstract
Molecular crystals of meso-(5-((4-formylphenyl)ethynyl)thiophen-2-yl)-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene 4a and ...meso-(4-((4-formylphenyl)ethynyl)phenyl)-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene 4b were synthesized using palladium(0)-catalyzed Sonogashira cross coupling reactions and characterized using an experimental-theoretical approach. The crystal structures of F-BODIPYs 4a-b are structurally analogous, yet their crystal packing motifs displayed remarkable differences due to contrasting hydrogen-bonding interactions. A CASTEP study of the unit cell for each compound provided the theoretical band structure and density-of-states (DOS) diagrams for each molecular crystal, suggesting a semiconductor character for both solids. Analysis of the computed electron density with Bader's QTAIM describes the intermolecular-contact network within each periodic system, while Natural Bonding Orbitals (NBO) display in-phase overlap between stacked units, denoting intermolecular delocalization of the electron density via stacking. TDDFT analysis of solution UV-Vis spectra gives insight into the nature of the observed excitations along with the effects derived from the relative rotation of π-subsystems in solution.
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•Molecular crystals were solved in the P -1 space group.•UV–vis excitations have been computed and correlated with the experiments.•The electron density for each unit cell was analyzed by QTAIM.•NBO mapping of intermolecular orbital overlap was derived.•Density of states was derived through CASTEP analysis.
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