Three imines comprised of 5-nitrothiophen-2-yl as electron-accepting and phenols as electron-donating groups were synthesized and used as chromogenic chemosensors to detect alkylamines. The compounds are colorless in water, but their deprotonation by the alkylamines generates the corresponding colored phenolates, which can be used to detect those analytes. The addition of cetyltrimethylammonium bromide (CTAB) causes bathochromic shift of the perichromic band of the phenolates, indicating that the compounds are transferred into the micelles. In addition, CTAB lowers the pKa of phenols and increases the stability of the phenolates, improving their performance as chemosensors. Applications were prospected with the chromogenic chemosensors adsorbed on strip papers to detect alkylamines in water and in the vapor phase. The compounds were also used in solution for the quantification of lidocaine in water. Thus, the versatility of the compounds studied allows to think about applications in industrial, environmental, and pharmaceutical areas.

Two novel compounds, 4-(pyren-1-ylimino)methylphenol and 4-[(triisopropylsilyl)oxy]phenylmethylenepyren-1-amine) were synthesized. Solutions of 4-(pyren-1-ylimino)methylphenol in dimethyl sulfoxide (DMSO) are colorless, but on addition of cyanide and fluoride they become colored due to the deprotonation of the chemosensor. The system is highly selective toward cyanide with the addition of water. This compound can be solubilized in water with addition of cetyltrimethylammonium bromide above its critical micellar concentration. The pKa of the compound in water was determined as 10.49 ± 0.02 and this value is lowered in micellar medium to 7.49 ± 0.02, which means that only cyanide is sufficiently basic to achieve the deprotonation of the compound. Solutions of 4-[(triisopropylsilyl)oxy]phenylmethylenepyren-1-amine) in DMSO are colorless, but they are colored in the presence of cyanide and fluoride and only cyanide could be detected in DMSO-water mixture. The nucleophilic attack of the anions on the silicon center of the compound releases colored 4-(pyren-1-ylimino)methylphenolate, enabling the detection of nucleophilic analytes.

<p>Three polymer-surfactant systems comprised of branched polyethylene imine (PEI) with an anionic surfactant (sodium dodecylsulfate; SDS), a cationic surfactant (tetradecyltrimethylammonium bromide; TTAB), and a zwitterionic surfactant (<italic>N</italic>-tetradecyl-<italic>N</italic>,<italic>N</italic>-dimethyl-3-ammonio-1-propanesulfonate; SB3-14) were studied based on the properties of surface tension, pyrene fluorescence emission, dynamic light scattering, pH, and zeta potential measurements. The critical aggregation concentration (<italic>cac</italic>) and polymer saturation point (<italic>psp</italic>) were determined for all three systems. The effect of these surfactants on the physico-chemical characteristics (diameter and surface charge) of the complexes formed was determined. Polymer-surfactant interactions occurred in all of the systems studied, with the strongest interactions, electrostatic in nature, occurring in the SDS-PEI system. After the neutralization of the polymer charges with the addition of the surfactant, the hydrophobic effect started to control the interlacing of the polymer chains. For the PEI-TTAB system, a very dense film was formed at surfactant concentrations above 2.0 mmol L^-1. In this case, the bromide counter-ion interacted with both the positively-charged PEI and the head of the surfactant, which is responsible for the formation of double layer coordination complexes. For the system composed of PEI and the zwitterionic surfactant, less cooperative associations occurred in comparison with the other systems.</p>

Biodegradable nanoparticles (NPs) have received considerable attention because of their possible use in the development of strategies for the topical delivery of oils and therapeutic drugs, particularly when drug penetration in dermis is desired. Zein is a prolamine and is a promising material for the design of drug delivery systems. In this study, NPs were prepared with zein and were used to encapsulate and release terpinen-4-ol, which is a therapeutic agent for the treatment of melanoma. The results show that the zein NPs are promising nanostructured systems for the prolonged delivery of T4OL with potential applications in anti-melanoma therapy.

A two-step experiment is proposed for a third year class in experimental organic chemistry. Over a period of five weeks, the students synthesized calix[4]pyrrole, a receptor that is highly selective for fluoride, and a pyridinium N-phenolate dye. Subsequently, the students used the synthesized compounds to investigate a displacement assay on the basis of the competition in acetonitrile between fluoride and the dye for calix[4]pyrrole. The experiment increased the students' skills in organic synthesis and in the characterization of organic compounds, provided a very attractive and accessible illustration of important supramolecular phenomena, and allowed the study of a chromogenic chemosensor.

Buscamos descrever e analisar as estratégias de produção simultânea de masculinidades hegemônicas e subalternas manifestadas no noticiário da imprensa de Florianópolis entre os anos de 1889 a 1930. Pelos artigos divulgados nos jornais da capital catarinense neste período é possível perceber a construção positivada das representações que envolvem uma masculinidade de homens brancos, jovens e viris, atentando para um código de urbanidade que passava a exigir um maior cuidado com o corpo e o domínio de si. Satisfazer a esse modelo valorizado socialmente era a garantia de que o homem desempenharia bem as responsabilidades que dele se esperava, como prover a família, produzir uma prole saudável, ser trabalhador, cumprir seus contratos e ser um bom cidadão. De modo articulado ao campo das políticas de gênero, os artigos buscavam constranger as mulheres no espaço privado, reservando aos homens a esfera pública. A exaltação de atributos de prestígio da masculinidade produz, de modo simultâneo, a representação do que é indesejável nas atitudes de um homem, notadamente nos espaços públicos. A partir da década de 1910, pode-se evidenciar com maior precisão a divulgação de uma série de práticas e representações que visavam a coibir comportamentos masculinos que deixavam de ser tolerados nos logradouros públicos da cidade. Entre tais comportamentos estava a prática da embriaguez e o uso da violência como forma de solução de conflitos interpessoais. Naquele contexto, passou-se a exigir dos homens que circulavam pela cidade certa previsibilidade em suas atitudes, associada ao uso da razão e em oposição aos modos violentos e impulsivos daqueles das classes baixas ou do ambiente rural. Na avaliação dos gestores da cidade, a emergência do progresso era atravancada por uma série de práticas culturais arraigadas na população. Por isso, não bastava simplesmente transformar o espaço urbano, era preciso também investir nos corpos dos habitantes da capital de Santa Catarina. Os comportamentos masculinos passaram então a ser alvo de toda uma série de ingerências que pretendiam adequá-los à nova realidade social e urbana que se buscava estabelecer.

The text describes and analyzes the strategies of simultaneous production of hegemonic and subordinate masculinities published in news media Florianópolis between the years 1889 to 1930. In articles published in newspapers of the capital can see the positive construction of representations of masculinity involving white men, young and virile, noting a code of civility that passed requiring greater care with body and self-control. Satisfying this model was socially valued the assurance that the man play and the responsibilities expected of him, as to provide the family, produce healthy offspring, be industrious, to fulfill their contracts and be a good citizen. Pivotally to the field of gender policies, the articles sought to embarrass the women in the private space, reserving to men the public sphere. The exaltation of prestige attributes of masculinity simultaneously produces a representation of what is undesirable in the attitudes of a man, especially in public spaces. From the 1910s, one can show more precisely the disclosure of a series of practices and representations aimed at curbing male behavior that ceased to be tolerated in public places in the city. Among such behavior was the practice of drunkenness and the use of violence as a means of solving interpersonal conflicts. In that context, it moved to require the men who went around the city some predictability in their attitudes, associated with the use of reason as opposed to violent and impulsive ways of men of lower class or rural environment. In the evaluation of the managers of the city, the emergence of progress was hampered by a series of cultural practices rooted in the population. Therefore, it was not enough simply to transform the urban space, it was also necessary to invest in the bodies of the inhabitants of the capital of Santa Catarina. The male behavior began to be targeted by a series of interference to adjust them to the new urban and social reality that sought to implement.

O composto 4-(4-nitrobenzilidenoamino)fenol foi utilizado em duas estratégias que permitem uma detecção altamente seletiva de F- e CN-. Primeiramente, observou-se que o composto em acetonitrila age como um quimiossensor cromogênico devido ao fato de que ânions básicos levam ao seu desprotonamento (solução incolor), resultando numa solução colorida contendo fenolato. A detecção seletiva de CN- sobre F- foi obtida adicionando-se 1,4% de água ao sistema: a água solvata preferencialmente o F-, enquanto o CN- fica relativamente livre para desprotonar o composto fenólico. Outra estratégia envolveu um ensaio de competição do fenolato e do analito pelo calix[4]pirrol em acetonitrila, um receptor altamente seletivo para F-. O fenolato e o calix[4]pirrol formam um complexo por ligação de hidrogênio, com mudança na cor do meio. Dentre diversos ânions, somente o F- foi capaz de restaurar a cor original correspondendo ao fenolato, pelo fato do ânion deslocá-lo do sítio de complexação.

4-(4-Nitrobenzylideneamine)phenol was used in two strategies allowing the highly selective detection of F- and CN-. Firstly, the compound in acetonitrile acts as a chromogenic chemosensor based on the idea that more basic anions cause its deprotonation (colorless solution), generating a colored solution containing phenolate. The discrimination of CN- over F- was obtained by adding 1.4% water to acetonitrile: water preferentially solvates F-, leaving the CN- free to deprotonate the compound. Another strategy involved an assay comprised of the competition between phenolate dye and the analyte for calix[4]pyrrole in acetonitrile, a receptor highly selective for F-. Phenolate and calix[4]pyrrole form a hydrogen-bonded complex, which changes the color of the medium. On the addition of various anions, only F- was able to restore the original color corresponding to phenolate in solution due to the fact that the anion dislodges phenolate from the complexation site.

Cyclodextrins (CDs) are cyclic oligosaccharides comprised of six or more glucose units connected by alpha-1,4 bonds. They have hydrophobic cavities with a hydrophilic exterior, and are versatile receptors for a variety of substrates. This ability allows them to be applied in many fields, as distinct as supramolecular chemistry, nanotechnology, pharmaceuticals, green chemistry, agrochemicals, analytical chemistry, toiletries, foods, and cosmetics. This review summarizes several aspects related to the physico-chemical properties of CDs and discusses their potential applications illustrated by recent examples. The prospects for their use in several areas are also described.

The detection of anionic species is a field which is currently attracting increasing interest. Research is carried out not only to gain a better understanding of biological events that anions participate in, but also to ascertain the potential contribution of the anionic chemosensors to the qualitative and quantitative analysis of species of interest in the areas of industry, medicine, the environment, and chemistry. This review summarizes several aspects related to the main strategies used in anion sensing. Each strategy discussed is illustrated with its potential applications citing recent examples. The prospects for their use in several areas are also described.

Dois pré-ligantes 2,2'-bipiridínicos 5,5'-dissubstituídos apresentando em sua estrutura dois ou três sítios de coordenação [5,5'-bis(ácido N-metil-hidroxâmico)-2,2'-bipiridina (4) e 5-metil-5'-(ácido N-metil-hidroxâmico)-2,2-bipiridina (10)] foram sintetizados. Estes ligantes foram empregados no estudo de uma estratégia de automontagem por complexação seqüencial. De acordo com este conceito, o primeiro metal adicionado organiza os substituintes-ligantes das posições 5,5' para a complexação do segundo íon metálico adicionado seqüencialmente. A adição de Fe2+ a uma solução contendo 4 levou à formação do complexo Fe2+-tris(bipiridil). A adição de Fe3+ a este complexo rendeu uma arquitetura trimetálica. O ligante 10 levou à formação de uma mistura de arquiteturas bimetálicas pela adição seqüencial de íons Fe2+ e Fe3+. No entanto, quando a ordem de adição foi alterada, somente um complexo bimetálico foi obtido. Isto se deve ao fato de que o primeiro metal adicionado (Fe3+) age como um molde, organizando os ligantes bipiridínicos e pré-formando uma cavidade adequada para o íon Fe2+.

Two multisite 5,5'-disubstituted 2,2'-bipyridine ligands containing N-methyl hydroxamic acids as substituents [5,5'-bis(N-methylhydroxamic)-2,2'-bipyridine (4) and 5-methyl-5'-(N-methylhydroxamic)-2,2-bipyridine (10)] were synthesized. These ligands were used in order to illustrate the strategy of self-assembly through sequential complexation. According to this concept, the first metal added organizes the ligands disposed in 5,5'-positions to accomodate the second metal ion that is sequentially added. Thus, addition of Fe2+ to a solution of 4 led to a Fe2+-tris(bipyridine) complex. Addition of Fe3+ to this solution yielded a trimetallic architecture, which was characterized. Ligand 10 yielded a mixture of bimetallic architectures through complexation with Fe2+ followed by Fe3+ ions. However, if the order of metal addition is changed, only one bimetallic complex is obtained. This is due to the fact that the first metal ion added (Fe3+) acts as a template, organizing the bipyridine ligands and preforming an adequate cavity for the Fe2+ ion.

This work summarizes important aspects of the chemistry of phosphate esters, with special emphasis on: i) advances in the design of enzymatic models for phosphatases; and ii) nerve agents and currently used strategies for detoxification. The physical organic chemical aspects that are responsible by the reactivity of phosphate esters are also discussed.

Ácidos húmicos (HA) extraídos de vermicompostos (VC) de estercos de ovelhas (SHHA), bovinos (COHA), caprinos (GOHA) e coelhos (RAHA) foram analisados com o auxílio das espectroscopias de ressonância paramagnética eletrônica e ressonância magnética nuclear de hidrogênio. Estas substâncias húmicas (HS) recentes são compostas por ácidos carboxílicos, fenóis, funções amina, amida, éster, éter, estruturas carbônicas alifáticas saturadas, alifáticas com ligações conjugadas, duplas e simples, ao lado de cadeias aromáticas. Foram caracterizados complexos de Mn2+ de esfera externa (SHHA, COHA), complexos de Fe3+ em estruturas axiais (GOHA, RAHA) e rômbicas (SHHA, COHA, GOHA e RAHA) e complexos de Cu2+ de campo fraco (COHA, GOHA, RAHA) e de campo forte (SHAHA, COHA, GOHA, RAHA).

Humic acids (HA) extracted from sheep (SHHA), cow (COHA), goat (GOHA) and rabbit (RAHA) vermicomposted manure were analyzed by electron paramagnetic resonance and hydrogen nuclear magnetic resonance spectroscopies. Carboxylic acids, amine, amide, ester, ether and phenol functions bonded to saturated aliphatic, unsaturated aliphatic conjugated double and single bonds, and aromatic chains constitute the backbone structure of these fresh humic substances (HS). Mn2+ outer sphere complexes (SHHA, COHA), Fe3+ axial (COHA, RAHA) or rhombic (SHAHA, COHA, GOHA, RAHA) complexes and Cu2+ as weak field (COHA, GOHA, RAHA) and strong field (SHAHA, COHA, GOHA, RAHA) complexes were characterized.

Os avanços recentes das pesquisas na área de sistemas inorgânicos automontados são resumidos neste artigo de revisão, em especial aqueles envolvendo os metalo-helicatos, os metalo-exorreceptores e as arquiteturas inorgânicas formadas a partir de componentes múltiplos. As aplicações, assim como as perspectivas vislumbradas para estes sistemas, são também discutidas.

This review summarizes the recent advances that have been performed on self-assembled inorganic systems, especially on helical systems, metallo-exoreceptors and on architectures formed from multiple components. In addition, applications as well as the perspectives for these designed systems are also discussed.

The chemical and biological properties of energy-rich phosphate compounds, e.g. ATP and acetyl phosphate, were revised. The role of water in the formation of this class of energy-rich compounds in biological systems is also discussed.