Journal of the Brazilian Chemical Society This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

Heterostructured Langmuir-Blodgett Films of Ruthenium Bipyridine with 1,3,4-Naphthooxadiazole-Derived Amphiphile Complex as a Charge Storage Electrode
The molecular control in Langmuir-Blodgett (LB) films may be exploited in charge storage electrodes provided a suitable choice of molecular architecture and components is made. In this paper, we employed a naphtyl-1,3,4-oxadiazole amphiphile (NFT1) and its complex [Ru(bpy)2NFT1]PF6 (RuNFT1) (bpy = 2,2 ’ -bipyridine) in heterostructured LB films in a proof-of-principle production of charge storage. The optimized architecture contained a one-layer RuNFT1 deposited on a 9-layer NFT1 LB film, where the efficient packing of NFT1 inferred from spectroscopic measurements and Brewster angle microscopy (BAM) images was considered...
Source: Journal of the Brazilian Chemical Society - October 30, 2020 Category: Chemistry Source Type: research

Where’s the Spin? A DFT Study of Mixed-Valence Cyanide-Bridged Ruthenium Polypyridines
This article discusses the use of density functional theory (DFT) calculations in classifying and characterizing bimetallic ruthenium mixed-valence systems in terms of their electronic localization/delocalization degree. A standard B3LYP/LanL2DZ methodology including integral equation formalism-polarizable continuum model (IEF-PCM) solvent model is evaluated for a set of 16 non-symmetric mixed-valence cyanide-bridged ruthenium polypyridines. This procedure reproduces well the features of the observed electronic and vibrational spectra, with better agreement for the more delocalized systems, and therefore provides an approp...
Source: Journal of the Brazilian Chemical Society - October 30, 2020 Category: Chemistry Source Type: research

Nickel-Cerium Layered Double Hydroxide as Electrocatalyst for Glycerol Oxidation
A new nickel based layered double hydroxide nanomaterial, Ni0.8Ce0.2-LDH, constituted by about 3 nm large nanoparticles exhibiting enhanced electrocatalytic properties towards oxidation of glycerol in alkaline media, was prepared by incorporation of 20 wt.% of CeIII ions into α -nickel hydroxide. This can be oxidized to CeIV, as demonstrated by X-ray photoelectron spectroscopy, a much electron withdrawing and oxidizing species responsible for electronic interactions and additional electrocatalytic active sites giving rise to synergic effects. High-resolution transmission electron microscopy images and the X-ray diffractog...
Source: Journal of the Brazilian Chemical Society - October 30, 2020 Category: Chemistry Source Type: research

Zeolite-SPION Nanocomposite for Ammonium and Heavy Metals Removal from Wastewater
Minimizing the emission of industrial effluents and realizing the recovery/extraction of key elements such as the rare earths from low concentration solutions, or during water decontamination processes, are some of the biggest challenges of modern society. Accordingly, the preparation and characterization of a low cost recyclable and reusable superparamagnetic iron oxide nanoparticles (SPION)/zeolite nanocomposite (Zmag) is described, and the possibility of their use for removal of heavy metals and ammonium/ammonia is discussed, generating water whose quality is in compliance with the more strict modern environmental laws....
Source: Journal of the Brazilian Chemical Society - October 30, 2020 Category: Chemistry Source Type: research

Self-Assembled Nanoparticles of Diruthenium(II,III)-Ibuprofen Anticancer Metallodrug
The diruthenium(II,III)-ibuprofen (RuIbp) metallodrug shows anticancer activity in vitro and in vivo. The encapsulation into lipid nanoparticles enhanced the efficacy in glioblastoma, breast and prostate cancer cells. Here we report data for RuIbp hydrophobicity, solubility in alcohol/water, and behavior in 1-5% ethanol/water and ethanol/cell culture medium. RuIbp is capable of spontaneously generate self-assembled RuIbpNP nanoparticles when drug ethanolic solutions are added to water or cell growth culture medium at 1-5% ethanol. The phenomenon was investigated, and the nanoparticles characterized. RuIbpNP nanoparticles f...
Source: Journal of the Brazilian Chemical Society - October 30, 2020 Category: Chemistry Source Type: research

NO Photorelease from a Ruthenium Complex Assisted by Formation of a Supramolecular Dimer
This work presents the NO release from compound [Ru(biq)2(H2O)(NO)](PF6)3 (biq = 2,2 ’ -biquinoline) with visible light irradiation ( λ irrad = 660 nm), assisted by the low-absorbing photosensitizer [Ru(biq)2Cl2]. The structure of both compounds were characterized by means of ESI-MS (electrospray ionization mass spectrometry). The NO+ stretching, ν (NO) = 1995 cm-1, is atypically shifted to higher energy. This observation, along with the E1/2 = 0.49 V (vs. Ag/AgCl) assigned to the Ru2+/3+ redox pair observed for compound [Ru(biq)2Cl2] and its photoreactivity in solution suggest that the RuII ion, when coordinated to tw...
Source: Journal of the Brazilian Chemical Society - October 30, 2020 Category: Chemistry Source Type: research

Performance of Water Oxidation by 3D Printed Electrodes Modified by Prussian Blue Analogues
The water oxidation is the limiting step in the water-splitting process. Given this scenario, the development of new catalysts is essential in this field. The emergent demand is the use of Earth-abundant elements and catalysts with high performance under mild conditions. Because of this, catalysts such as Prussian Blue analogues (PBA) have been receiving a lot of attention in recent years. In addition, working under neutral conditions allows us to take advantage of the modification of conductive polymeric 3D printed electrodes (3DPE) with Prussian Blue. Thus, we described in this work the development of the polymeric 3D pr...
Source: Journal of the Brazilian Chemical Society - October 30, 2020 Category: Chemistry Source Type: research

A Symmetrical Dirhenium(I) Complex with 4,4’’-Azobis(2,2’-bipyridine) as a Bridging Ligand: Synthesis, Physicochemical Properties and Applications in Detection of Biologically Relevant Thiols and in Chemotherapy for Bone Cancer
A new dinuclear complex of formula [{Re(CO)3(py)}2( µ-4,4 ” -azobpy)](PF6)2, with py = pyridine and 4,4 ” -azobpy = 4,4 ” -azobis(2,2 ’ -bipyridine), has been synthesized and characterized by spectroscopic and electrochemical techniques. The symmetrical nature of the dimetallic cation has been confirmed by nuclear magnetic resonance (NMR) measurements. When adding L-cysteine or L-glutathione, large and rapid changes in its UV-Vis absorption spectra were observed, which can be used for detecting both biologically relevant thiols. A promising activity for using this complex as a chemotherapeutic agent for bone cance...
Source: Journal of the Brazilian Chemical Society - October 30, 2020 Category: Chemistry Source Type: research

Synthesis, Characterization, Spectroelectrochemical, Photophysical and HSA-Binding Properties of Novel and Versatile meso-Tetra(4-pyridylvinylphenyl)porphyrins Coordinated to Ruthenium(II)-Polypyridyl Derivatives
The free-base meso-tetra(4-pyridylvinylphenyl)porphyrin (1a) and its zinc(II) complex were synthesized and then functionalized with [Ru(bpy)2Cl]+ units (2a and 2b) via conventional methods and evaluated in terms of photophysical, electrochemical and biological aspects. All porphyrins present moderate singlet oxygen production and fluorescence quantum yield, and did not show any aggregation process. The photo-oxidation ability of those porphyrins decreased in the order 2b> 1a> 2a. The electrochemical behavior of 2a and 2b modified electrodes was evaluated by electroanalytical methods. Also the 2b electrode showed a sm...
Source: Journal of the Brazilian Chemical Society - October 30, 2020 Category: Chemistry Source Type: research

Gold Nanoparticle/Tetrapyridylporphyrin Hybrid Material: Spectroscopic and Electrocatalytic Properties and Sensor Application
An electrocatalytic active hybrid material prepared by successive stepwise coordinative deposition of 20 nm diameter gold nanoparticles (AuNP) with 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine (TPyP) on fluorine-doped tin oxide (FTO) substrates previously modified with 3-mercaptopropylsilane is described. Their interaction and assembly were studied by UV-Vis spectroscopy and surface enhanced Raman spectroscopy to understand the kinetics as well as the conformation on the porphyrin macrocycle on the electrode surface as a function of its concentration. The hybrid nanomaterial was a build-up in reproducible successive deposi...
Source: Journal of the Brazilian Chemical Society - October 30, 2020 Category: Chemistry Source Type: research

Design, Synthesis, and Application of Colored Cobalt Pigments (Pink, Blue, Green)
The combination of white or colorless oxides (MgO, Al2O3, ZnO) with colorant ions (Co2+) generates colored pigments (pink, blue, green). The color is caused by the insertion of the colorant ion in the respective crystal lattices (periclase, alumina, wurtzite), as verified by X-ray diffraction. Absorption spectra in the visible region show analogous triplet behavior of the absorption bands for the doped alumina and wurtzite samples but a difference in tetrahedral distortion, which generates blue and green pigments. In contrast, cobalt-doped periclase has color-related parameters related to the pink color. Crystallite and pa...
Source: Journal of the Brazilian Chemical Society - October 30, 2020 Category: Chemistry Source Type: research

Effect of Push-Pull Ruthenium Complex Adsorption Conformation on the Performance of Dye Sensitized Solar Cells
A new series of tris-(bipyridyl)ruthenium-like complexes based on the 4-tripheylamine-2,2 ’ :6 ’ ,2 ’ ’ -terpyridine (TPA) push-pull ligand was prepared by incorporation of 4-carboxypyridine (cpy), 4,4 ’ -dicarboxi-2,2 ’ -bipyridine (dcbpy) and 4-carboxyterpyridine ligands (ctpy) ligands, in order to adsorb them on TiO2 in different anchoring conformations. The electron photoinjection and electron recombination processes of the respective dye-sensitized solar cells were greatly influenced by the molecular structure, which defined the surface concentration and surface charge on TiO2, such that the photoconversio...
Source: Journal of the Brazilian Chemical Society - October 30, 2020 Category: Chemistry Source Type: research

“Half-Sandwich”/RuII Anticancer Complexes Containing Triphenylphosphine and p-Substituted Benzoic Acids
Mononuclear and binuclear RuII/arene/triphenylphosphine complexes with p-substituted benzoic acid derivatives were prepared and characterized. These monocationic complexes of type [Ru( η 6-p-cymene)(PPh3)L] (L = benzoic acid (1), p-hydroxybenzoic acid (2), p-nitrobenzoic acid (3) and terephthalic acid (4)) were characterized using various techniques, such as nuclear magnetic resonance (NMR) and matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry, and the crystal structure of 1, 3 and 4 were determined by X-ray diffraction analysis. The cytotoxicity of the complexes was evaluated, in vi...
Source: Journal of the Brazilian Chemical Society - October 30, 2020 Category: Chemistry Source Type: research

Improvements in Methyl-Bambus[6]uril Synthesis Yield
Bambus[n]uril synthesis may be challenging, and it is frequently achieved with low purity and low yields. We have studied the effect of different anions on the synthesis of bambus[6]uril, especially in terms of yield, exploring template effects driven by anions in the reaction medium. The influence of the anions is evident on such syntheses and ClO4 − particularly led to unprecedented synthesis yields. Computational calculations have also been used to elucidate the influence of anions on cyclization process. (Source: Journal of the Brazilian Chemical Society)
Source: Journal of the Brazilian Chemical Society - October 30, 2020 Category: Chemistry Source Type: research

Preparation of Fluorescent Carbon-Based Dots from Waste Tire Pyrolysis
The pyrolysis of waste tire has been proposed as an alternative route to its recycling producing residual oils that can be used as fuels. In this work, a physicochemical process to obtain carbon-based dots (CBD) from carbon black (CBL) derivatives of tires is described. For this, the CBL was treated with different acids to produce CBL1 and CBL2 particles suspension. The pH of the suspension was adjusted to 5.6 to precipitate remaining impurities. Afterwards, the supernatant was ultra-centrifuged and the yellow pale solid, the purified CBD obtained by roto evaporation, was characterized by ultraviolet-visible spectrophotome...
Source: Journal of the Brazilian Chemical Society - October 30, 2020 Category: Chemistry Source Type: research