JBCS



10:25, sáb fev 15

Acesso Aberto/TP



vol. 38, No. 1, 2015



Artigo de Capa
Quim. Nova 2015, 38(1), 22-29

Efeito da estrutura molecular de ligantes de superfície em pontos quânticos de CdTe dispersos em água

Brener R. C. Vale; Kayo O. Vieira; José C. L. Sousa; Jefferson L. Ferrari; Marco A. Schiavon*

With increasing particle sizes of water-soluble mercaptoethylamine-capped CdTe, the trap band energy stabilizes until the material reaches a critical size. Thereafter, the TB is not observed in the photoluminescence spectra.

http://dx.doi.org/10.5935/0100-4042.20140292

Publicado online: outubro 24, 2014
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Total access: 2313

Artigo Quim. Nova 2015, 38(1), 1-7

 

A influência da ligação de hidrogênio em reações químicas: reação de Prileschajew

Mauro A. Bueno; Boaz G. Oliveira*


The epoxidation mechanism known as the Prileschajew reaction was reinvestigated through the formation of hydrogen bonds between C2H4O and HCO2H.

http://dx.doi.org/10.5935/0100-4042.20140296

Publicado online: outubro 27, 2014
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Quim. Nova 2015, 38(1), 8-13

 

The application of automated correlation optimized warping to the quality evaluation of Radix puerariae thomsonii: correcting retention time shift in the chromatographic fingerprints

Long JiaoI,*; Shan BingI; Xiaofei WangI; Zhiwei XueII; Hua LiIII


Automated correlation optimized warping is a practical method for aligning the chromatographic fingerprints of Radix Puerariae thomsonii. After this alignment, the quality of Radix Puerariae thomsonii can be correctly evaluated.

http://dx.doi.org/10.5935/0100-4042.20140276

Publicado online: outubro 8, 2014
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Quim. Nova 2015, 38(1), 14-21

 

Biofilms based on canihua flour (Chenopodium Pallidicaule): design and characterization

Lady M. Salas-ValeroI,*; Delia R. Tapia-BlácidoII; Florencia C. MenegalliI


The flours isolated from canihua grains (Chenopodium Pallidicaule) can form films that have low water vapor permeability and act as a good barrier to incident ultraviolet light. Films formed from both varieties of canihua grains used in this study (cupi and illpa-inia) presented a single vitreous transition temperature (< 0 °C) and show promise for potential applications in food packaging.

http://dx.doi.org/10.5935/0100-4042.20140275

Publicado online: outubro 8, 2014
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Total access: 1684

Quim. Nova 2015, 38(1), 30-36

 

Distribuição e fracionamento do Hg em sedimentos do rio Paraíba do Sul - RJ, Brasil

Beatriz Ferreira Araujo*; Marcelo Gomes de Almeida; Thiago Pessanha Rangel; Carlos Eduardo de Rezende#


Our results confirm the key role played by mangroves in controlling the fate of mercurial compounds in coastal areas. Consequently, mangrove deforestation should be considered a major source of environmental risk in tropical and subtropical coastal regions.

http://dx.doi.org/10.5935/0100-4042.20140268

Publicado online: outubro 6, 2014
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Total access: 1930

Quim. Nova 2015, 38(1), 37-41

 

Di-hidrocucurbitacina B: semi-síntese de novos derivados glicosilados

Vanessa R. MachadoI; Karen L. LangII; Fernando J. DuránII; Gabriela M. CabreraIII; Jorge A. PalermoIII; Eloir P. SchenkelI; Lílian S. C. BernardesI,*


Novel glycoside derivatives of dihydrocucurbitacin B were synthesized under Köenigs-Knorr and imidate reaction conditions.

http://dx.doi.org/10.5935/0100-4042.20140291

Publicado online: outubro 24, 2014
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Total access: 1738

Quim. Nova 2015, 38(1), 42-45

 

Chemical study of Hortia superba (Rutaceae) and investigation of the antimycobacterial activity of crude extracts and constituents isolated from Hortia species

Vanessa Gisele Pasqualotto SeverinoI,*; Afif Felix MonteiroI; Maria Fátima das Graças Fernandes da SilvaII; Rodrigo LucariniIII; Carlos Henrique Gomes MartinsIII


The picture describes the methodology used in the biological evaluation of Hortia species against Mycobacterium tuberculosis H37Rv, M. kansasii and M. avium, and the compounds that exhibited promising MIC values against M. tuberculosis H37Rv.

http://dx.doi.org/10.5935/0100-4042.20140290

Publicado online: outubro 24, 2014
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Total access: 1706

Quim. Nova 2015, 38(1), 46-54

 

Esterificação e transesterificação simultâneas de óleos ácidos utilizando carboxilatos lamelares de zinco como catalisadores bifuncionais

Luiz Pereira RamosI,II,*; Ricardo José BrugnagoI; Fabiano Rosa da SilvaI; Claudiney Soares CordeiroI,II; Fernando WypychI


Response surface demonstrating the ability of zinc carboxylates to promote the simultaneous esterification and transesterification of palm oil with 40% in free fatty acids.

http://dx.doi.org/10.5935/0100-4042.20140274

Publicado online: outubro 8, 2014
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Total access: 2537

Quim. Nova 2015, 38(1), 55-59

 

Influência do tratamento térmico no nanocompósito fotocatalisador ZnO/TiO2

Maria Terezinha C. Sansiviero*; Dalva Lúcia A. de Faria


ZnO/TiO2 nanocomposites were treated at different temperatures, and anatase, ZnO, and ZnTiO3 were formed when the sample was heated at 600 ºC, whereas the main phases obtained above 750 ºC were rutile and ZnTiO3. The presence of ZnTiO3 in the sample had no significant effect on the nanocomposite photocatalytic activity.

http://dx.doi.org/10.5935/0100-4042.20140267

Publicado online: outubro 6, 2014
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Quim. Nova 2015, 38(1), 60-65

 

Novos flavonoides de Margaritopsis carrascoana com atividade antioxidante

Raimundo Regivaldo G. NascimentoI; Jackelyne A. MonteiroI; Antônia Torres A. PimentaI; Maria Teresa S. TrevisanI; Raimundo Braz-FilhoII; Elnatan Bezerra de SouzaIII; Edilberto R. SilveiraI; Mary Anne S. LimaI,*


Two new flavonoids and other known compounds were obtained from extracts of the leaves and stems of Margaritopsis carrascoana. All isolated compounds showed higher antioxidant activity, while the extract of the stems showed strong AChE inhibition.

http://dx.doi.org/10.5935/0100-4042.20140289

Publicado online: outubro 24, 2014
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Total access: 2622

Quim. Nova 2015, 38(1), 66-70

 

Volatile components from galls induced by Baccharopelma dracunculifoliae (Hemiptera: Psyllidae) on leaves of Baccharis dracunculifolia (Asteraceae)

Michele Aparecida Besten*,I; Domingos Sávio NunesI; Daniel GranatoII; Sávio Luis SensII; Alberto Wisniewski JrIV; Edesio Luis SimionattoV; Dilamara Riva-ScharfV


This article presents the first GC-MS analyses of volatiles from galls induced by Baccharopelma dracunculifoliae and the results are compared with those from healthy Baccharis dracunculifolia leaf samples.

http://dx.doi.org/10.5935/0100-4042.20140288

Publicado online: outubro 24, 2014
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Total access: 2206

Quim. Nova 2015, 38(1), 71-76

 

Global and local reactivity descriptors for picloram herbicide: a theoretical quantum study

Luis H. Mendoza-Huizar*


The most reactive sites on picloram for electrophilic, free radical, and nucleophilic attacks have been determined.

http://dx.doi.org/10.5935/0100-4042.20140283

Publicado online: outubro 16, 2014
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Total access: 1525

Quim. Nova 2015, 38(1), 77-84

 

Avaliação de métodos de solubilização para determinação de metais em glicerina proveniente da produção de biodiesel por técnicas de espectrometria atômica

Caroline D. Clasen; Meibel T. Lisboa; Ane Martiele T. P. Pinto; Anderson S. Ribeiro; Mariana A. Vieira*


Evaluation by atomic spectrometry of simple and fast solubilization methods for the determination of Ca, Mg, and K in glycerin samples obtained from biodiesel production.

http://dx.doi.org/10.5935/0100-4042.20140287

Publicado online: outubro 24, 2014
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Total access: 2419

Quim. Nova 2015, 38(1), 85-90

 

Investigação do uso de eletrodo de carbono vítreo modificado com hexacianoferrato de rutênio para detecção de procaína

Thalita G. Silva; Maiara O. Salles; Thiago R. L. C. Paixao*


The use of a glassy carbon electrode modified with ruthenium hexacyanoferrate was investigated. The aim was to detect procaine in abused drugs and pharmaceutical formulations.

http://dx.doi.org/10.5935/0100-4042.20140286

Publicado online: outubro 24, 2014
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Total access: 2234

Quim. Nova 2015, 38(1), 91-96

 

Nanopartículas de proteína isolada de soja em água: efeito da força iônica e das concentrações de proteína e surfactante

Samira J. FayadI,*; Betina G. Z. RamosII; Valdir SoldiI; Edson MinattiI


Soy protein isolate nanoparticles were obtained through the coacervation of an aqueous protein solution. Morphology and stability analyses were followed by light scattering and microscopy analyses.

http://dx.doi.org/10.5935/0100-4042.20140295

Publicado online: outubro 27, 2014
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Total access: 1995

Revisão Quim. Nova 2015, 38(1), 97-105

 

A versatilidade dos compostos de coordenação na produção de polietilenos: uma revisão dos sistemas catalíticos

Emanoel Igor da Silva OliveiraI; Fernando SilveiraII; Adelaide Maria Vieira ViveirosI; Nara R. S. BassoIII; Zênis Novais da RochaI; Joao H. Z. dos SantosIV,*


Various types of polyethylene can only be obtained because of the possibility of modulating coordination compounds used as catalysts in the polymerization process. Both the metal center and the ligands can be tuned, giving versatility to such systems.

http://dx.doi.org/10.5935/0100-4042.20140282

Publicado online: outubro 9, 2014
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Total access: 3511

Quim. Nova 2015, 38(1), 106-117

 

Óxidos de nióbio: uma visão sobre a síntese do Nb2O5 e sua aplicação em fotocatálise heterogênea

Osmando F. LopesI,II; Vagner R. de MendonçaII; Fernando B. F. SilvaI,II; Elaine C. ParisII; Caue RibeiroII,*


The following scheme depicts the application sequence of niobium oxide nanoparticles from an appropriate Nb source to heterogeneous photocatalysis. Aspects such as the morphology, band gap, and surface area are defined by the nanoparticles' synthetic parameters, which also influence the catalyst performance.

http://dx.doi.org/10.5935/0100-4042.20140280

Publicado online: outubro 8, 2014
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Total access: 3370

Quim. Nova 2015, 38(1), 118-127

 

Arsênio e arroz: toxicidade, metabolismo e segurança alimentar

Juliana M. O. SouzaI; Maria F. H. CarneiroI; Ana Carolina C. PaulelliI; Denise GrottoII; Ariano M. Magalhaes JúniorIII; Fernando Barbosa JúniorI; Bruno L. BatistaI,IV,*


Rice plants have the tendency to absorb different arsenic species. This cereal is a staple food for half of the global population. According to FAO/WHO, the arsenic level of rice is an increasing concern in food safety. Understanding the plant's mechanisms and monitoring its safety are imperative.

http://dx.doi.org/10.5935/0100-4042.20140279

Publicado online: outubro 8, 2014
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Total access: 2831

Nota Técnica Quim. Nova 2015, 38(1), 128-131

 

Construção de um reator de plasma descarga corona para eliminação de compostos orgânicos voláteis

Marina Medeiros Machado; Marília Medeiros Machado; Ana Regina de Aguiar Dutra; Elisa Helena Siegel Moecke; Anelise Leal Vieira Cubas*


A cold plasma reactor was built with low-cost materials in order to degrade volatile organic compounds such as BTEX, known for their adverse effects on human health.

http://dx.doi.org/10.5935/0100-4042.20140270

Publicado online: outubro 6, 2014
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Total access: 1830

Quim. Nova 2015, 38(1), 132-135

 

Construção de um dispositivo de pressurização a vácuo para a preparação de fases estacionárias monolíticas via processo Sol-Gel

Sandro Pereira RibeiroI; Fernando Antonio Simas VazI; Marcone Augusto Leal de OliveiraI,*; Thiago de Oliveira MendesII; José Paulo Rodrigues Furtado de MendonçaII


This high pressurization device allows the capillary to be filled with a sol solution through either positive or negative (vacuum) pressure. The latter procedure averts contact between sol and the syringe thus avoiding damage.

http://dx.doi.org/10.5935/0100-4042.20140263

Publicado online: setembro 22, 2014
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Total access: 1703

Quim. Nova 2015, 38(1), 136-143

 

Aparato eletroquímico para sistema de aquisição de dados multicanal com resolução espaço-temporal

Raphael Nagao; Melke A. Nascimento; Hamilton Varela*


An electrochemical setup for a multichannel data acquisition system was developed in order to obtain spatiotemporal resolution during the electrooxidation of small organic molecules.

http://dx.doi.org/10.5935/0100-4042.20140281

Publicado online: outubro 8, 2014
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Educação Quim. Nova 2015, 38(1), 144-150

 

A formação de professores em comunidades de prática: o caso de um grupo de professores de química em formação inicial

Valéria C. Santos*; Agnaldo Arroio


This graphical abstract outlines the main elements of the research. The group represents a community of practice in chemistry teaching.

http://dx.doi.org/10.5935/0100-4042.20140234

Publicado online: agosto 27, 2014
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Total access: 2040

Quim. Nova 2015, 38(1), 151-155

 

Avoiding first-year university chemistry textbooks' misrepresentations in the teaching of spontaneous reactions

Ana Quílez-Díaz; Juan Quílez-Pardo*


The calculation (and the sign) of DrG establishes the direction of a chemical reaction. Q-K inequalities are accurate options. However, the use of the sign of Δ,Gº or Le Châtelier's principle leads to incorrect predictions.

http://dx.doi.org/10.5935/0100-4042.20140248

Publicado online: setembro 5, 2014
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Total access: 1595

Quim. Nova 2015, 38(1), 156-158

 

Método de síntese de azidas aromáticas usando vinagre

Kauanna Naguissa Hino; Alvaro Takeo Omori*


A simple and low-cost procedure for preparation of aryl azides is described. Vinegar (renewable source) can be used as solvent/reagent.

http://dx.doi.org/10.5935/0100-4042.20140284

Publicado online: outubro 16, 2014
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Total access: 2769

Nota de Retrataçao Quim. Nova 2015, 38(1), 160

 

Adsorption of a copper (II) complex on calcium phosphate intercalated with 4-aminobenzoic acid - synthesis and electrochemical investigation

Camila F. N. SilvaI; Fernando M. de SouzaI; Jéssica P. SantosI; Ana Paula B. DiasI; Ana Paula R. SantanaI; Angélica M. LazarinI,*; Rosana L. SernagliaI; Elza I. S. AndreottiI; Claudio AiroldiII


http://dx.doi.org/10.5935/0100-4042.20150318

Publicado online: julho 17, 2013
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Total access: 1739

Geral Quim. Nova 2015, 38(1), i-iv

 

On-line version ISSN 1678-7064 Printed version ISSN 0100-4042
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