JBCS

13:58, Sat Aug 19

Open Access/APCs

vol. 24, No. 7, 2013, p. 1079-1211

 

The Reaction of 1,2-Dichloro-4,5-dinitrobenzene with Hydroxide Ion: Roles of Meisenheimer Complexes and Radical Pairs

There is evidence for the Single Electron Transfer Mechanism as an alternative to the classical heterolytic model of aromatic nucleophilic substitution of the reaction of OH- with 1,2-dichloro-4,5-dinitrobenzene, involving the displacement of nitro group, to form the final product 2-nitro-4,5-dichlorophenol. Details are presented in the Article The Reaction of 1,2-Dichloro-4,5-dinitrobenzene with Hydroxide Ion: Roles of Meisenheimer Complexes and Radical Pairs by Andrei Blaskó, Clifford A. Bunton, Nichollas D. Gillitt, Radu Bacaloglu, Santiago F. Yunes and César Zucco on page 1146.

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Cover Article
J. Braz. Chem. Soc. 2013, 24(7), 1146-1159

The Reaction of 1,2-Dichloro-4,5-dinitrobenzene with Hydroxide Ion: Roles of Meisenheimer Complexes and Radical Pairs

Andrei Blaskó; Clifford A. Bunton; Nichollas D. Gillitt; Radu Bacaloglu; Santiago F. Yunes; César Zucco

How to cite this article

There is evidence for the Single Electron Transfer Mechanism as an alternative to the classical heterolytic model of aromatic nucleophilic substitution of the reaction of OH- with 1,2-dichloro-4,5-dinitrobenzene, involving the displacement of nitro group, to form the final product 2-nitro-4,5-dichlorophenol. Details are presented in the Article The Reaction of 1,2-Dichloro-4,5-dinitrobenzene with Hydroxide Ion: Roles of Meisenheimer Complexes and Radical Pairs by Andrei Blaskó, Clifford A. Bunton, Nichollas D. Gillitt, Radu Bacaloglu, Santiago F. Yunes and César Zucco on page 1146.

http://dx.doi.org/10.5935/0103-5053.20130148

Published online: June 18, 2013

Articles J. Braz. Chem. Soc. 2013, 24(7), 1079-1084

Convenient Solvatochromic Probes for the Determination of Solvent Properties: β-Carotene and 2-Chloro-7-nitro-9H-fluorene

Omar A. El Seoud; Paulo A. R. Pires; Carina Loffredo; Muhammad Imran; Paolo D. Pulcini; Michelle F. Corrêa; Rizwana Mustafa

How to cite this article

 

The solvatochromic probes 2-(N,N-Dimethylamino)-7-nitro-9H-fluorene and the commercially available β-carotene and 2-chloro-7-nitro-9H-fluorene can be conveniently employed for determining the properties of solvents and their mixtures.

http://dx.doi.org/10.5935/0103-5053.20130142

Published online: June 7, 2013


J. Braz. Chem. Soc. 2013, 24(7), 1085-1098

Comprehensive Two-Dimensional GC with TOF-MS Detection: Study of Pyrolytic Bio-Oil of Kraft Mill Residues

Candice S. Faccini; Isadora Dalla Vecchia; Desyrre Ribeiro; Claudia A. Zini; Elina B. Caramão

How to cite this article

 

Color plots of bio-oils obtained from pyrolysis of three pulp mill residues and analyzed with comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometric detection (GC×GC/TOFMS) unveil the complexity and potential of these materials for industrial use.

http://dx.doi.org/10.5935/0103-5053.20130143

Published online: June 7, 2013

J. Braz. Chem. Soc. 2013, 24(7), 1099-1108

Debromination of endo-(+)-3-Bromocamphor with Primary Amines

Svetlana Marković; Violeta Marković; Milan D. Joksović; Nina Todorović; Ljubinka Joksović; Vladimir Divjaković; Snezana Trifunović

How to cite this article

 

Ethanolamine and ethylene diamine debrominate 3-bromocamphor giving the corresponding camphanimines in good isolated yields. The yield of the obtained camphanimines strongly depends on solvent polarity and steric demand of the applied amine. The reaction mechanism was investigated by means of density functional theory (DFT) calculations.

http://dx.doi.org/10.5935/0103-5053.20130144

Published online: June 7, 2013


J. Braz. Chem. Soc. 2013, 24(7), 1109-1115

Grafting Amino Drugs to Poly(styrene-alt-maleic Anhydride) as a Potential Method for Drug Release

Ardeshir Khazaei; Shahnaz Saednia; Javad Saien; Masoud Kazem-Rostami; Mahdieh Sadeghpour; Maryam Kiani Borazjani; Fatemeh Abbasi

How to cite this article

 

Novel types of polymer-drug conjugates based on PSMA with pendant medicinal compounds were synthesized, characterized. Hydrolysis reactions were also studied, and then drug release kinetics and mechanisms were reported to introduce a controlled drug delivery system.

http://dx.doi.org/10.5935/0103-5053.20130145

Published online: June 11, 2013


J. Braz. Chem. Soc. 2013, 24(7), 1116-1122

Use of Saccharomyces cerevisiae Yeasts in the Chemoselective Bioreduction of (1E,4E)-1,5-Bis(4-Methoxyphenyl)-1,4-Pentadien-3-one in Biphasic System

César A. Schaefer; Vanessa D. Silva; Boris U. Stambuk; Maria da G. Nascimento

How to cite this article

 

The biotransformation using baker's yeast (BY) from Fleischmann as catalyst in aqueous/organic solvent biphasic system was chemoselective and formed the saturated ketone. The concentration of BY and substrate, temperature, pH and Vaq/Vorg, influenced the reduction, and DMSO was the best co-solvent.

http://dx.doi.org/10.5935/0103-5053.20130140

Published online: June 14, 2013


J. Braz. Chem. Soc. 2013, 24(7), 1123-1134

Characterization and Corrosion Resistance of Anodic Electrodeposited Titanium Oxide/Phosphate Films on Ti-20Nb-10Zr-5Ta Bioalloy

Monica Popa; Cora Vasilescu; Silviu I. Drob; Petre Osiceanu; Mihai Anastasescu; Jose M. Calderon-Moreno

How to cite this article

 

AFM micrographs showed that the electrodeposited film has a porous microstructure and good roughness. X-ray photoelectron spectroscopy (XPS) superimposed spectra indicated that the coating deposited over time had a variable composition: nanocrystalline hydroxyapatite nucleated at the inner layer, and amorphous calcium phosphate was formed at the outer layer.

http://dx.doi.org/10.5935/0103-5053.20130146

Published online: June 14, 2013

J. Braz. Chem. Soc. 2013, 24(7), 1135-1145

Classification of Honeys from Pará State (Amazon Region, Brazil) Produced by Three Different Species of Bees using Chemometric Methods

Antonio dos S. Silva; Cláudio N. Alves; Kelly das G. Fernandes; Regina C. S. Müller

How to cite this article

 

Flowchart of the analysis of metal contents in samples of honey from bees from Amazonia (Brazil) and dendrogram with separation of the three types of honeys studied.

http://dx.doi.org/10.5935/0103-5053.20130147

Published online: June 18, 2013

J. Braz. Chem. Soc. 2013, 24(7), 1146-1159

The Reaction of 1,2-Dichloro-4,5-dinitrobenzene with Hydroxide Ion: Roles of Meisenheimer Complexes and Radical Pairs

Andrei Blaskó; Clifford A. Bunton; Nichollas D. Gillitt; Radu Bacaloglu; Santiago F. Yunes; César Zucco

How to cite this article

 

The major reaction of OH- with 1,2-dichloro-4,5-dinitrobenzene in H2O-DMSO involves the displacement of the nitro group, and transient Meisenheimer complexes are detected. Free radicals are detected in solvents of low water content, but not under the kinetic conditions.

http://dx.doi.org/10.5935/0103-5053.20130148

Published online: June 18, 2013

J. Braz. Chem. Soc. 2013, 24(7), 1160-1166

Nonsteroidal Anti-Inflammatory Drug Determination in Water Samples by HPLC-DAD under Isocratic Conditions

Loreto Ascar; Inés Ahumada; Alicia López; Francia Quintanilla; Karla Leiva

How to cite this article

 

The purpose of this study was to implement an analytical method that permits the determination of the presence of nonsteroidal anti-inflammatory drugs (NSAIDs) in water. Compound extraction was performed by solid-phase extraction (SPE) using an Oasis HLB cartridge. Analytes were analyzed by a simple method using HPLC-DAD.

http://dx.doi.org/10.5935/0103-5053.20130150

Published online: June 21, 2013

J. Braz. Chem. Soc. 2013, 24(7), 1167-1171

Pyrrolizidine Alkaloids and Diterpenes from Villasenoria orcuttii

Amira Arciniegas; Ana L. Pérez-Castorena; Karina González; Marisol Reyes-Lezama; José Luis Villaseñor; Alfonso Romo de Vivar

How to cite this article

 

Two new acyclic diterpenes, as well as the pyrrolizidine alkaloids florosenine and floridanine, among other known compounds, were isolated from Villasenoria orcuttii. The absolute stereochemistry of floridanine was determined by X-ray analysis and its NMR data were corrected.

http://dx.doi.org/10.5935/0103-5053.20130149

Published online: June 21, 2013


J. Braz. Chem. Soc. 2013, 24(7), 1172-1179

Solid-Phase Extraction of Cu(II) Using Polyurethane Foam and Eriochrome Black T as Ligand for its Determination in Waters by Flame Atomic Absorption Spectrometry

Silvio Soriano; Ricardo J. Cassella

How to cite this article

 

Scheme of the procedure employed for the selective preconcentration of Cu(II) with polyurethane foam and eriochrome black T as ligand, aiming its determination in waters by flame atomic absorption spectrometry.

http://dx.doi.org/10.5935/0103-5053.20130151

Published online: June 25, 2013

J. Braz. Chem. Soc. 2013, 24(7), 1180-1187

Optimization of the Synthesis of SAPO-11 for the Methylation of Naphthalene with Methanol by Varying Templates and Template Content

Xiaoxiao Wang; Wei Zhang; Shaoqing Guo; Liangfu Zhao; Hongwei Xiang

How to cite this article

 

A set of SAPO-11 zeolites was synthesized by a hydrothermal method using different templates (diethylamine (DEA), di-n-propylamine (DPA) and di isopropylamine (DIPA)) and varying DPA content (nDPA/Al2O3 = 0.8, 1.2, 1.6 and 2.0). SAPO-11(DPA,1.2) exhibited the highest catalytic performance in the methylation of naphthalene with methanol.

http://dx.doi.org/10.5935/0103-5053.20130152

Published online: June 25, 2013

J. Braz. Chem. Soc. 2013, 24(7), 1188-1197

Multiresidue Determination and Uncertainty Analysis of Pesticides in Soil by Ultrafast Liquid Chromatography Coupled to Mass Spectrometry

Diego A. Ahumada; Luis A. Arias; Carlos R. Bojacá

How to cite this article

 

This work shows the results obtained in the validation and characterization of a method for the analysis of pesticide residues in soil by modern analytical techniques. Ultrafast liquid chromatography coupled to mass spectrometry was used, and statistical analysis was performed according to international standards in order to ensure the reliability of the results.

http://dx.doi.org/10.5935/0103-5053.20130153

Published online: June 25, 2013


J. Braz. Chem. Soc. 2013, 24(7), 1198-1205

Simultaneous Determination of Rifampicin and Isoniazid in Urine and Pharmaceutical Formulations by Multivariate Visible Spectrophotometry

Sandra Stets; Talita M. Tavares; Patricio G. Peralta-Zamora; Christiana A. Pessoa; Noemi Nagata

How to cite this article

 

A simple chemical derivatization of rifampicin and isoniazid modifies the spectral behavior of these drugs and allows their simultaneous determination using visible spectrophotometry by applying multivariate calibration (PLS).

http://dx.doi.org/10.5935/0103-5053.20130154

Published online: June 25, 2013

Short Report J. Braz. Chem. Soc. 2013, 24(7), 1206-1211

Ultramicroelectrode Array Behavior of Electrochemically Partially Blocked Boron-Doped Diamond Surface

Giancarlo R. Salazar-Banda; Katlin I. B. Eguiluz; Adriana E. de Carvalho; Luis A. Avaca

How to cite this article

 

Boron-doped diamond electrode surfaces can act as partially blocked or with heterogeneous electroactivity, depending on the polarization, that is, anodic or cathodic, respectively. This was demonstrated using the ferro/ferri-cyanide redox couple at very low scan rates.

http://dx.doi.org/10.5935/0103-5053.20130141

Published online: June 7, 2013

Online version ISSN 1678-4790 Printed version ISSN 0103-5053
Journal of the Brazilian Chemical Society
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