| Author (s): |
IONESCU, Lavinel G.
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| Title: |
THE SOUTHERN BRAZILIAN JOURNAL OF CHEMISTRY COMPLETES 20 YEARS OF PUBLICATION |
| Abstract: |
With this issue, THE SOUTHERN BRAZILIAN JOURNAL OF CHEMISTRY completes twenty (20) years of continuous uninterrupted publication. The printed version of the JOURNAL has been distributed in more than Fifty (50) countries of the globe, covering all continents. We are well aware that at the present time when globalization and the centralization of information and control of many other human activities are in vogue, we may be appearing to go against the mainstream, or even in the opposite direction. As we stated in the first issue of the SOUTHERN BRAZILIAN JOURNAL OF CHEMISTRY twenty years ago we are still open for the debate and discussion of education, history, and philosophy of science and still hope, in a modest way to contribute to the analysis and solution of the crisis of moral and ethical values and standards that affects science and education an over the world.
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| Keywords: |
THE SOUTHERN BRAZILIAN JOURNAL OF CHEMISTRY.
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| Year: |
2012
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| Initial page: |
1
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| Final page: |
2
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v20.n20.2012.5_Revista_2012a.pdf |
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| Author (s): |
IONESCU, Lavinel G.
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| Title: |
OTTO RICHARD GOTTLIEB, FATHER OF BRAZILIAN PHYTOCHEMISTRY |
| Abstract: |
Otto R. Gottlieb was born in Brno, Czechoslovakia on August 3.l, 1920, and passed away in Rio de Janeiro, Brazil on June 19, 2011. They immigrated to Br in 1939 and did their undergraduate studies at the Universidade do Brasil, where he obtained a degree in industrial chemistry in PUS. He was awarded a doctorate in chemistry by the Universidade Federal Rural do Rio de Janeiro in 1966. He worked in industry and held positions at several institutes and universities in Brazil. His research work dealt mainly with phytochemistry, natural and medicinal products, and biodiversity. He was the research advisor of approximately 150 students and is responsible for approximately 700 scientific publications. Otto R. Gottlieb may be considered the father of Brazilian Phytochemistry.
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| Keywords: |
Phytochemistry, natural products, chemistry in Brazil, history of science .
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| Year: |
2012
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| Initial page: |
3
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| Final page: |
10
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v20.n20.2012.7_Revista_2012a.pdf |
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| Author (s): |
MEESRAGANDA, Sreedevi; ALURU, Raghavendra Gum Prasad; NARASIMBA, Spoorthy Yadan, RAO, Ravindnmath Laxmana Rao Krishna
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| Title: |
SYNTHESIS, CHARACTERIZATION AND ANTIMICROBIAL STUDIES ON CERTAIN SUBSTITUTED ARYLAZO IMIDAZOLE CONTAINING OXADIAZOLES |
| Abstract: |
A series of novel substituted l-[5-(2-methyl-5-nitro-4phenyl-imidazol-lyl methyl)-2-phenyl-(1,3,4)oxadiazol-3-yl]-ethanones have been synthesized. Formation of 1,3,4-oxadiazole ring was accomplished by the reaction of the corresponding hydrazide with acetic anhydride. The structure determination of these compounds has been made on the basis of IR, 1H NMR, and elemental analysis. All the compounds were screened for their antibacterial activity. The antimicrobial activity of title compounds were examined against two gram-negative (Staphylococcus aureus and Bacillus subtilis), two gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa), and antifungal activity was carried out against Candida albicans. The MIC values for the newly synthesized compounds have been assessed by serial dilution method All the compounds demonstrated potent antibacterial activity.
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| Keywords: |
Imidazol, 1,3,4-oxadiazol, atividade antimicrobianas.
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| Year: |
2012
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| Initial page: |
11
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| Final page: |
24
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v20.n20.2012.15_Revista_2012a.pdf |
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| Author (s): |
TOKUHIRO, Tadashi; CAREY, Joshua W.; REED, Rolanda M.; AKELLA, Sita S.
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| Title: |
SELECTIVE CAPTURE AND ENCAPSULATION OF METALLIC CATIONS BY HYDROGELS CONSISTING OF COPOLY(N-ISOPROPYLACRYLAMIDE/FUNCTIONAL MONOMER) NETWORKS |
| Abstract: |
Under the U.S. Department of Energy Waste Treatment Baseline and Integrated Waste Management Strategy the recycling of spent nuclear fuel to minimize waste, to assure maximum energy recovery, and to pursue science-based R&D to possibly eliminate the need for geologic waste repositories, are programmatic goals. We have developed both polymer gel and porous materials for the separation and adsorption of targeted contaminants. Here, we have investigated capture and encapsulation capabilities of hydrogels consisting of thermally-sensitive copoly[N-isopropylacrylamide(1-x) / functional monomer(x)] networks, where functional denotes carboxylic, hydroxyl, or cyanide group (mol fraction x); the captured and encapsulated species were: Cr3+, Co2+, Cu2+, Ni2+, Eu3+, Ho3+ and Tb3+ present in aqueous medium. Natural diffusions of cations into gel phase and the physico-chemical affinity of functional groups for cations played a major role in capturing cations. Encapsulation of cations trapped in hydrogels was achieved by loss of water and conformational transformation of networks through a volumetric phase transition. Experimental determinations of cation amounts (mass) and copolymer composition were carried out by atomic absorption and elemental analyses of carbon, nitrogen and hydrogen, respectively. We developed two approaches for determination of efficiency and selectivity metrics describing capture and encapsulation of cations by functional groups using two theories: 1) mean field theory and 2) first-order thermodynamic perturbation theory. The integrated results thus obtained show that: Cu2+ and Co2+ were selectively encapsulated by carboxylic and cyanide groups, respectively. Carboxylic and hydroxyl groups were superior extractants for Cr3+, Eu3+ and Ho3+. Further the cyanide group was also efiective for Eu3+ and Ho3+. However, all functional groups examined here were ineffective in capture and encapsulation ofNi2+.
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| Keywords: |
Hydrogels, networks, capture, metallic cations, N-isopropylacrylamide, fanctional monomer, waste remediatioin, lanthanides rare earths .
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| Year: |
2012
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| Initial page: |
25
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| Final page: |
41
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v20.n20.2012.29_Revista_2012a.pdf |
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| Author (s): |
A.A.El-Khouly; E. A. Gomaa; S. E. Salem
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| Title: |
CONDUCTOMETRIC STUDY OF COMPLEX FORMATION BETWEEN 2,3-PYRAZINEDICARBOXYLIC ACID AND SOME TRANSITION METAL IONS IN METHANOL |
| Abstract: |
The complexation reactions between CuCl2 CoCL2 and NiCL2 with 2,3-Pyrazinedicarboxylic acid in methanol (MeOH) at 313.15 K were studied by conductometric methods. The association constants, formation constants and Gibbs free energies were calculated from the conduclometric titration curves. On drawing the relation between molar conductance and the ratio of metal to ligand coflCentrations, different lines were obtained indicating the formation of 1: 1 and 2: 1 (M:L) stoichiometric complexes. The formation constants and Gibbs free energies of different complexes in absolute Methanol at 313.15 Kfollow the order:
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| Keywords: |
Association constants; formation constants; Gibbs free energies of association; Gibbs free energies of complex formation. .
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| Year: |
2012
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| Initial page: |
43
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| Final page: |
50
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v20.n20.2012.46_Revista_2012a.pdf |
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| Author (s): |
Hany M. M. Dalloul
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| Title: |
SYNTHESIS OF NEW SPIRO-HETEROCYCLES CONTAINING DIHYDROTETRAZINE MOIETY |
| Abstract: |
The reaction of nitrilimines with hydrazones of alkanones and cycloalkanones led to the formation of acyclic electrophHic addition products, which upon treatment with C/S/Zn cyclized to 1,6-dihydro-1,2,4,5-tetrazine derivatives. The structures of the synthesized compounds have been established by their elemental analyses and spectroscopical data.
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| Keywords: |
Nitrilimines, Hydrazones, Cyclization, Synthesis, 1,6-dihydro-1,2,4,5-tetrazine .
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| Year: |
2012
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| Initial page: |
51
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| Final page: |
60
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v20.n20.2012.54_Revista_2012a.pdf |
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| Author (s): |
GUPTA, RAJUL; FULORIA, Neeraj Kumar; FULORIA, Shivkanya
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| Title: |
SYNTHESIS AND ANTIMICROBIAL PROFILE OF SOME NEWER HETEROCYCLES BEARING THIAZOLE MOIETY |
| Abstract: |
Various substituted acetophenones on treatment. with iodine and thiourea yielded 2-amino-4-( substituted-phenyl)-thiazole, which on further treatment with acetic anhydride generated N-(4-(substituted phenyl)thiazol-2-ylacetamide(1-5). All the synthesized compounds were characterized by their respective FTIR, 1H NMR, and mass data. Synthesized compounds (l, 2, 3, 4, 5) when subjected to investigation for their antimicrobial activities i.e. antibacterial and antifungal studies against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Aspergillus flavus, and Aspergillus fumigatus by disk diffusion method, revealed that compound 2 deemed to be most potent with the largest zone of inhibition.
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| Keywords: |
Thiazole, acetophenones, antimicrobial, substituted aldehydes.
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| Year: |
2012
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| Initial page: |
61
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| Final page: |
67
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v20.n20.2012.64_Revista_2012a.pdf |
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| Author (s): |
CHAUBAN, Vishal; FULORIA, Sbivkanya; FULORIA, Neeraj K.; HASHIM, Syed R.; KUMAR, Sokindra
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| Title: |
SYNTHESIS, CHARACTERIZATION AND COMPARATIVE SCREENING OF SOME NEWER 2-PHENYL INDOLE AND 5-CHLORO-2-PHENYL INDOLE DERIVATIVES |
| Abstract: |
Biologically active phenyl indole and chloro phenyl indole derivatives were efficiently synthesized. The reaction of 2-phenyl-1H-indole A and 5-chloro-2-phenyl-1H-indole B, with chloroacetylchloride yielded 2-chloro-1-(2-phenyl-1H-indol-1-yl)ethanone 1 and 2-chloro-1-(5-chloro-2-phenyl-1H-indol-1-yl)ethanone 4 respectively. Compound 1 and 4 on Friedal Crafts cyclization in presence of aluminium chloride and nitrobenzene yielded indolo[2,1 -alfa]isoquinolin-6(5H)-one 2 and 10-chloroindolo [2,1-alfa]isoquinolin-6(5H)-one 5 respectively, which upon hydrolysis afforded 2-(2-(1H-indol-2-yl)phenyl)acetic acid 3 and 2-(2-(5-chloro-1H-indol-2-yl) phenyl) acetic acid 6 respectively. The newly designed compounds were characterized on the basis of spectral studies and screened for anti-inflammatory andanti-microbial activities.
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| Keywords: |
2-phenyl-indole, 5-chloro-2-phenyl-indole, Friedal Crafts cyclization.
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| Year: |
2012
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| Initial page: |
69
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| Final page: |
76
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v20.n20.2012.71_Revista_2012a.pdf |
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| Author (s): |
EL-ASKALANY, A. H.; MOSTAFA S. I.; EID A. M.
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| Title: |
GREEN INHIBITORS FOR CORROSION PROTECTION OF N80 CARBON STEEL IN 1M HCl AQUEOUS SOLUTIONS |
| Abstract: |
The inhibitive action of Saponinic extract of both Zygophylium album and Zygophylium Egyptian leaves which could serve as eco-friendly materials was investigated on the corrosion of N80 carbon steel in 1 M HCl solution. The techniques employed for the study were weight loss measurements. potentiodynamic polarization, electrochemical frequency modulation (EFM), and electrochemical impedance spectroscopy (EIS). The results obtained show that these extracts could serve as an effective inhibitor for N80 carbon steel. The percentage inhibition increases with increasing concentration of the inhibitor at 25 °C The percentage inhibitor efficiency above 90% was obtained at a concentration of 700 ppm for both extracts. The corrosion rates of steel and inhibitive efficiencies obtained from impedance and polarization measurements were in good agreement with those obtained from weight loss measurements. Potentiodynamic polarization studies clearly reveal that both extracts act as mixed-type inhibitors The study shows that the inhibition efficiency decreased with the temperature rise of the medium. Heat of adsorption and thermodynamic parameters and indicated that the adsorption process is mainly controlled by the physical adsorption process.
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| Keywords: |
Green inhibitors, N80 carbon steel, corrosion protection .
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| Year: |
2012
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| Initial page: |
77
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| Final page: |
98
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v20.n20.2012.79_Revista_2012a.pdf |
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| Author (s): |
DAS NEVES, Paulo Cesar Pereira; IONESCU, Lavinel G.
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| Title: |
BERYLLIUM MINERALS |
| Abstract: |
Beryllium is a chemical element composition of the Group 2 of the Periodic Table of Chemical Elements. It does not crystallize as a natural solid and exhibits a crustal abundance of 2.8 ppm. It is a chemical element among the trace elements with low representativity, together with erbinm and bromine. It shows a big chemical reactivity, and a low abundance in the chemical composition of minerals (only 96 minerals have beryllium in their chemical compositions). The principal beryllium-bearing minerals for industrial usages are beryl and bertrandite, and secondary sources are helvite, chrysoberyl, euclase, beryllonite, and phenakite. This review presents a synopsis of the beryllium-bearing minerals as a contribution to the scientific knowledge of these substances.
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| Keywords: |
Beryllium, beryllium-bearing minerals, uses of beryllium.
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| Year: |
2012
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| Initial page: |
99
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| Final page: |
118
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v20.n20.2012.101_Revista_2012a.pdf |
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