Journal of the Brazilian Chemical Society (J BRAZIL CHEM SOC)

Publisher: Sociedade Brasileira de Química

Journal description

Publication of the Sociedade Brasileira de Química. Mission: To publish research papers in all fields of chemistry, except education, philosophy and history of chemistry.

Current impact factor: 1.13

Impact Factor Rankings

2015 Impact Factor Available summer 2016
2014 Impact Factor 1.129
2013 Impact Factor 1.253
2012 Impact Factor 1.283
2011 Impact Factor 1.434
2010 Impact Factor 1.343
2009 Impact Factor 1.458
2008 Impact Factor 1.43
2007 Impact Factor 1.539
2006 Impact Factor 1.003
2005 Impact Factor 1.097
2004 Impact Factor 1.161
2003 Impact Factor 0.895
2002 Impact Factor 1.036
2001 Impact Factor 0.619
2000 Impact Factor 0.402
1999 Impact Factor 0.436
1998 Impact Factor 0.472
1997 Impact Factor 0.293

Impact factor over time

Impact factor

Additional details

5-year impact 1.39
Cited half-life 6.20
Immediacy index 0.14
Eigenfactor 0.01
Article influence 0.29
Website Journal of the Brazilian Chemical Society website
Other titles Journal of the Brazilian Chemical Society (Online)
ISSN 0103-5053
OCLC 60637846
Material type Document, Periodical, Internet resource
Document type Internet Resource, Computer File, Journal / Magazine / Newspaper

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of this study was to synthesize TiO2-polymer composites able to act as photocatalyst membranes. TiO2 catalysts were prepared using the sol-gel method to contain 0.0, 0.5, 1.0, and 2.0 wt.% of embedded Ag particles, subsequently incorporated into natural rubber latex at a weight fraction of 15%. Samples of these ceramic powders were suspended in a latex emulsion (natural rubber), cast in Petri dishes and slowly dried in an oven. The resulting materials were evaluated by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray, diffuse reflectance spectroscopy, differential scanning calorimetry, thermogravimetry, and photocatalytic assaying using methylene blue as an organic pollutant reference. All composite membranes exhibited good photoactivity conferred by TiO2 powder, with 98% dye fading after 300 min of ultraviolet irradiation.
    Journal of the Brazilian Chemical Society 11/2015; 00(00):1. DOI:10.5935/0103-5053.20150293
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    ABSTRACT: MnCo2O4/Au was investigated as an electrocatalyst for the oxygen reduction and evolution in alkaline media. Polarization curves showed an unprecedented activity for the oxygen reduction due to a synergistic effect between MnCo2O4 and Au, involving CoII/CoIII-MnIII/MnIV, as revealed by in situ X-ray absorption near edge structure (XANES). Additionally, results showed favorable interaction between the oxide and Au, which enhanced the activity for the oxygen evolution reaction.
    Journal of the Brazilian Chemical Society 11/2015; 26(11). DOI:10.5935/0103-5053.20150232
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    ABSTRACT: Avenanthramides play a role as phytoalexins in oat. Recently, various bioactivities have been found in avenanthramides as an antioxidant activity, anti-inflammatory, anti-atherogenic and anti-proliferative effect. In this study, the optimal conditions for the extraction of avenanthramides 2c, 2p and 2f from oat grain, cultivar Avenuda, were determined using response surface methodology (RSM). The effects of three independent variables (methanol concentration, extraction temperature and time) on the yield of aventhramides were investigated. A second-order polynomial model adequately fitted the experimental data with the R2 values of 0.959, 0.970 and 0.984 for the response of avenanthramides 2c, 2p and 2f, respectively. The optimization method which combined RSM with desirability function was chosen to find the best extraction conditions. The optimal conditions for the highest yield of avenanthramides were a methanol concentration of 70%, extraction temperature 55 °C and time 165 min. Under these conditions, the yields of avenanthramides 2c, 2p and 2f were 9.70 ± 0.38 mg kg-1, 10.05 ± 0.44 mg kg-1 and 19.18 ± 0.80 mg kg-1 oat grain, respectively.
    Journal of the Brazilian Chemical Society 11/2015; 26(11). DOI:10.5935/0103-5053.20150233
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    ABSTRACT: We present here our results in the synthesis of eleven new 3-(1H-1,2,3-triazol-1-yl)-2-(arylselanyl)pyridines by copper-catalyzed azide-alkyne cycloaddition reactions. The reactions were performed in the presence of catalytic amount of copper(II) acetate and sodium ascorbate using a mixture of tetrahydrofuran/water (1:1) as solvent at room temperature in air. The reaction is tolerant to different functional groups such as substituted-benzene rings, alcohol and ester and none electronic or steric influence was observed. All the products were obtained in good to excellent yields. Alternatively to the conventional oil bath heating, the use of microwave irradiation or ultrasound methods is also presented as alternative energy sources.
    Journal of the Brazilian Chemical Society 11/2015; 26(11). DOI:10.5935/0103-5053.20150221
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    ABSTRACT: Terpenes are the main constituents of hops essentiol oil and contribute to the singular sensory properties of beer. However, terpenes are sensitive to oxidation leading to quality loss during beer aging. Herein, the reactivity of terpenes towards 1-hydroxyethyl radical has been determined employing a competitive kinetic approach using the spin-trap α-(4-pyridyl-1-oxide)-N-tert-butylnitrone (4-POBN). The apparent rate constant (kapp) for the reaction of terpenes with 1-hydroxyethyl radical ranges from (3.9 ± 0.2) × 105 to (1.5 ± 0.2) × 107 L mol -1 s-1 for β-pinene and terpinolene, respectively. The reaction involves hydrogen atom transfer from the terpene to 1-hydroxyethyl radical rather than electron-transfer and the rate constant is shown to be dependent on the number of allylic and benzylic hydrogen atoms and on the value of the bond dissociation enthalpy for the weakest C-H bond. The results provide a better understanding on the mechanism behind terpene decomposition in beer brewing and aging process and may further contibute to improve the oxidative stability of the herb-flavored beverages.
    Journal of the Brazilian Chemical Society 11/2015; 26(11). DOI:10.5935/0103-5053.20150231
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    ABSTRACT: This paper describes an efficient approach for the synthesis of a novel series of sixteen 2-(5-trifluoromethyl-1H-pyrazol-1-yl)-5-(5-trihalomethyl-1H-pyrazol-1-yl-1-carbonyl) pyridines, for the first time with non-identical substituents in both pyrazole rings, through the cyclocondensation reaction of 4-methoxy-4-alkyl(aryl/heteroaryl-1,1,1∗-trihaloalk-3-en-2-ones [CX3 C(O)CH=CR1OCH3, in which R1 = CH3, C6H5, 4-CH3C6H4, 4-OCH3C6H4, 2-furyl and X = F, Cl] or acetylacetone with some 6-[3-alkyl(aryl)-5-trifluoromethyl-1H-pyrazol-1-yl]nicotinohydrazides. Optimized yields of 67-91% were obtained when the reactions were performed in ethanol (green solvent) at reflux for 16 h. Subsequent antioxidant and antimicrobial evaluation revealed promising 1,1-diphenyl-2-picrylhydrazyl (DPPH) inhibition percentage and exhibited fungiostatic and fungicidal activities against yeasts, dermatophytes and filamentous, especially for the pyridine systems, when the both pyrazole rings attached to a pyridine ring contain CX3groups (X = H, F, Cl) of different kinds. It is also observed the trichloromethyl substituted compounds presented higher antioxidant activity in comparison to their fluorinated analogous.
    Journal of the Brazilian Chemical Society 11/2015; 26(11). DOI:10.5935/0103-5053.20150230
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    ABSTRACT: Carbenoids are a class of highly reactive reagents that play an important role in modern organic synthesis. These species are very similar to singlet state carbenes since they have an ambiphilic character and react by a concerted mechanism allowing stereospecific transformations. Herein, we discuss these and other chemical aspects of zinc, lithium and magnesium carbenoids as well as relevant applications of these intermediates in organic synthesis.
    Journal of the Brazilian Chemical Society 11/2015; 26(11). DOI:10.5935/0103-5053.20150218
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    ABSTRACT: Tris-heteroleptic ruthenium(II) cis-[Ru(Me4-phen)(dcbH2)(NCS)2], where Me4-phen = 3,4,7,8-tetramethyl-1,10-phenanthroline, dcbH2 = 4,4'-dicarboxylic acid 2,2'-bipyridine, was synthesized, purified and characterized. Its characteristics were compared with those determined for cis-[Ru(Me2-phen)(dcbH2)(NCS)2] and cis-[Ru(phen)(dcbH2)(NCS)2] aiming to evaluate the effect of the number of methyl groups on the properties of the compounds. Changes in the Fourier transform infrared (FTIR) and 1H nuclear magnetic resonance (NMR) spectra indicated a modification in the electronic distribution of the complex because of the presence of methyl groups at the 3 and 8 positions of 1,10-phenanthroline. These changes also modified the excited state properties and resulted in a blue shift of the absorption and emission spectra. The complex was incorporated onto TiO2 to prepare dye-sensitized solar cells, achieving up to JSC = 11.9 mA cm-2, VOC = 0.627 V, ff = 0.67 and η = 5.0%.
    Journal of the Brazilian Chemical Society 11/2015; 26(11). DOI:10.5935/0103-5053.20150208
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    ABSTRACT: A method using dispersive liquid-liquid microextraction (DLLME) based on low density solvent (LDS) combined with liquid chromatography with diode array detection (LC-DAD) has been developed for determination of parabens. Some DLLME parameters such as kind and volumes of extraction and disperser solvents, pH of the aqueous samples, ionic strength, extraction, centrifugation and speed time, were investigated. The method exhibits good linearity (0.9990 to 0.9993), limits of detection (0.5-0.8 μg L-1), and limits of quantification (1.3-2.4 μg L-1). In optimum conditions, enrichment factors and recoveries of studied parabens obtained were 38.9 to 88.4% and 30.3 to 68.0%, respectively. Surface water samples collected from Mogi Guaçu River (São Paulo state, Brazil) were analyzed, showing average contents of methyl-, ethyl-, propyl-, and n-butylparaben of 8.0, 5.8, 13.1 and 15.1 μg L-1, respectively. This is the first study on parabens in a Brazilian River, in a long stretch of river (ca. 300 km of extension).
    Journal of the Brazilian Chemical Society 11/2015; 26(11). DOI:10.5935/0103-5053.20150206
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    ABSTRACT: Validating methodology formerly reported, polythiophene electrosynthesised as nanowires from the monomer and some of its oligomers is now described. The work is conducted on a platinum electrode previously modified with a template that tunes the polymer growth inside the confined space of the pores. In addition, it was confirmed that the use of larger chain-length oligomers as starting unit helps to obtain more homogeneous wires, although its adhesion to the supporting substrate works against. Characterisation allows to verify the morphology and to confirm higher levels of doping/undoping of the nanostructures as compared to the corresponding bulky deposits, which points to improved macroscopic properties. It is demonstrated that this strategy allows obtaining nanowires of very small diameter, ranging from 2.8 to 4.0 nm; thus demonstrating that the use of this approach enables the direct obtainment of nanowires upon the electrode surface, with the obvious advantage that this implies.
    Journal of the Brazilian Chemical Society 11/2015; 26(11). DOI:10.5935/0103-5053.20150223
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    ABSTRACT: In this study, the monitoring of pesticide residues, which show potential for environmental contamination, in center-pivot irrigated areas in the Brazilian cerrado, was performed. The pesticides monitored were acephate, atrazine, azoxystrobin, buprofezin, carbofuran, cyproconazole, chlorpyrifos, difenoconazole, diuron, imidacloprid, malathion, methamidophos, metolachlor, metribuzin, monocrotophos, monuron, thiamethoxam, and triazophos. Surface water samples were collected upstream and downstream of Tijunqueiro dam. The subsurface water in piezometric wells was drilled in the surroundings of the irrigated area; fish and sediment were collected in the dam. The technique of solid phase extraction (SPE) was used for the extraction of water samples, the matrix solid phase dispersion (MSPD) for the sediment samples and QuEChERS (quick, easy, cheap, effective, rugged and safe) for the fish samples. The multiresidue methods used were accurate and precise for most pesticides monitored by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Atrazine was detected in two of the subsurface water samples.
    Journal of the Brazilian Chemical Society 11/2015; 26(11). DOI:10.5935/0103-5053.20150215
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    ABSTRACT: This article discusses a simple approach for the microwave-assisted synthesis of good quality nanosized calcium titanate crystals doped with trivalent Tm and Yb lanthanide ions. The prepared nanoparticles had a microcube-like structure and a crystallite size of ca. 47 nm. The structure of the nanocrystals was analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and their spectroscopic behavior was examined at a laser excitation wavelength of 350.7 nm. It was found that doping CaTiO3 nanocrystals with Yb and Tm leads to about 250-fold brighter photoluminescence (PL) emissions in the blue and near-infrared regions than that emitted by pure CaTiO3 nanocrystals. The PL emission was correlated with the structural disorder.
    Journal of the Brazilian Chemical Society 11/2015; 26(11). DOI:10.5935/0103-5053.20150229
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    ABSTRACT: In this work, a batch adsorption study was conducted to investigate the removal efficiency of lead, copper and zinc ions from aqueous solutions. Magnetic amine-functionalized mesoporous silica nanoparticles were synthesized by grafting amine groups within the channels of magnetic mesoporous silica nanocomposites. Morphological and structural characterizations were made by X-ray powder diffraction, N2 adsorption-desorption, scanning and transmission electron microscopy, Fourier transform infrared spectroscopy and elemental analysis. Among different factors influencing the sorption process, solution pH, shaking time and mass of adsorbent were investigated. The removal efficiencies were higher than 98% under optimized experimental conditions. Maximum adsorption capacities calculated by the Langmuir model were 268, 93 and 82 mg g-1, for lead(II), copper(II) and zinc(II) ions, respectively. Accuracy and applicability of the synthesized adsorbent was estimated by analyzing spiked natural water samples and good recoveries (> 95%) were obtained with no matrix interferences.
    Journal of the Brazilian Chemical Society 11/2015; 26(11). DOI:10.5935/0103-5053.20150211