| Author (s): |
Irinel Badea, Philippe Cotelle and Jean-Pierre Catteau
|
| Title: |
AN EFFICIENT METHOD FOR THE SYNTHESIS OF NEW SUBSTITUTED CHROMENS |
| Abstract: |
The chromen derivatives can be obtained in excellent yields, in three steps, using first the phase transfer catalysis for the synthesis of phenol ether followed by cyclisation and the Perkin reaction
|
| Keywords: |
Lipoxygenase inhibitors, Phase Transfer Catalysis (PTC), Chromens.
|
| Year: |
2001
|
| Initial page: |
1
|
| Final page: |
4
|
| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v9.n10.2001.4_2001.pdf |
|
|
| Author (s): |
lrinel Badea, Philippe Cotelle and Jean-Pierre Catteau
|
| Title: |
A VERSATILE PROCEDURE FOR THE SYNTHESIS OF NEW PRENYLATED CINNAMIC ACIDS |
| Abstract: |
The prenylated cinnamic acids can be obtained in excellent yields, in two steps, using first a one-step conversion of corresponding bromobenzaldehydes to corresponding prenylated benzaldehydes
|
| Keywords: |
Lipoxygenase inhibitors, metallation, n butyl lithium, prenylated cinnamic acid.
|
| Year: |
2001
|
| Initial page: |
5
|
| Final page: |
8
|
| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v9.n10.2001.8_2001.pdf |
|
|
| Author (s): |
Vitor de Cinque Almeida, Luzia Otilia Bortotti Favero and Ervim Lenzi
|
| Title: |
RESPONSE OF THE COMMON CABBAGE (Brassica oleracea L. var. capitata L.) TO BORON FERTILIZATION |
| Abstract: |
The response of the common cabbage (Brassica oleracea L. var. capitata L.) to boron fertilization in soils of the state of Paranii, Brazil, is provided Six types of soils, LRd; LRe, Ca1; Ca2, TRd, and LEd were selected, treated with macronutrient fertilizer, their pH was corrected, according to routine. The experiment was conducted in 2.5-L capacity pots, with 2 kg of each soil, in a greenhouse. Each type of soil, in triplicate samples, received boron treatment with boric acid: 0.0 g; 0.1 g; 0.2 g. Pots were kept at 70% water capacity retention for 7 days, after which they received 6 cabbage shoots. Two shoots were maintained and later only one was kept in each pot. The duration of the experiment was 8 weeks, after which harvest was undertaken. Plants were dried in stoves, weighted, ground, and conditioned for further analysis. Extractor HCl 0.05 mol L-1 was used to determine boron in soils. Although soils Ca1, LRd, and LEd gave significant responses to treatments, concentrations of available boron over 4 μg g-1 were toxic to cabbages.
|
| Keywords: |
boron, micronutrients, cabbage, fertilization.
|
| Year: |
2001
|
| Initial page: |
9
|
| Final page: |
16
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v9.n10.2001.12_2001.pdf |
|
|
| Author (s): |
Cezar Spinu, Angela Kriza, Aurelia Meghea, Cristian Tigae
|
| Title: |
STUDIES ON N-[2-THIENYLMETHYLIDENE)-2-AMINOPYRIDINE COMPLEXES OF Fe(II), Co(II), Ni(II), Cu(II), Zn(II) AND Cd(II) |
| Abstract: |
Metal complexes ML2Cl2, where M is Fe(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) and L is Schiff base formed by condensation of 2-thiophenecarboxaldehyde and 2-aminopyridine, N-[2-thienylmethylidene]-2-arninopyridine (TNAPY), have been prepared and characterized by elemental analysis, magnetic and spectroscopic measurements. IR and NMR spectra show that the nitrogen of the azomethyne group and the sulphur of the thiophene ring take part in coordination. Magnetic, ESR and electronic spectral studies show a distorted octahedral structure for the Fe(II), Co(II), Ni(II) and Cu(II) complexes and a tetrahedral geometry for the Zn(II) and Cd(II) complexes. Conductance measurements suggest the nonelectrolytic nature of the complexes, with the exception of the Zn(TNAPY)2Cl2 and Cd(TNAPY)2Cl2 compounds which are 1:2 electrolytes.
|
| Keywords: |
Schiff base, N-[2-thienylmethylidene)-2-aminopyridine, NMR, ESR, Transition Metal Complexes.
|
| Year: |
2001
|
| Initial page: |
17
|
| Final page: |
22
|
| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v9.n10.2001.20_2001.pdf |
|
|
| Author (s): |
Paraschiv Balea and Gheorghe Potcovaru
|
| Title: |
A QUEUEING MODEL FOR SOME CATALYTIC REACTIONS |
| Abstract: |
The waiting model associated to the catalytical process given by the chemical eq_uation C + S ↔ CS ↔ C + P (1), is described by the Markov process: {Xi(t); t≥O}, (i = 1, 2, 3, 4), where the random variables are the concentrations of the species C (the catalyst), S (the substrate}, CS (the intermediate complex formed by the substrate S and the catalyst) and P (the reaction product) at time t. The equations, that describe the evolution of the process, have been obtained.
|
| Keywords: |
waiting model, catalytic processes , Markov process.
|
| Year: |
2001
|
| Initial page: |
23
|
| Final page: |
30
|
| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v9.n10.2001.26_2001.pdf |
|
|
| Author (s): |
Ion Gănescu, George Brătulescu, Ion Papa, Anca Gănescu, Cristian Tigae and Daniela Cartana
|
| Title: |
CHROMIUM (III) COMPLEX ANIONS IN THE CHEMICAL ANALYSIS. THIORIDAZINE DETERMINATION |
| Abstract: |
Complex anions of Cr(III) analogues of Reinecke s salt, [Cr(NCS)4(amine)2] are good analytical reagents with high sensibility and selectivity for N-organic bases of pharmaceutical importance. We have observed that the phenothiazinic type drug, thioridazine, prescribed for the treatment of maniac-depressing psychosis precipitates with Cr(/11) complex anions. Some new oxidative methods for the determination of thioridazine (10-[2-(1-methyl-2-piperidinyl)ethyl]-2-(methylthio)-10H-phenothiazine) are described The results were evaluated statistically
|
| Keywords: |
chromium (III), thioridazine, drugs, oxidimetric and spectrometric methods.
|
| Year: |
2001
|
| Initial page: |
31
|
| Final page: |
39
|
| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v9.n10.2001.34_2001.pdf |
|
|
| Author (s): |
B. I. Silveira, J.E. Blasquez, A. E. Dantas, and R. K. P. Santos
|
| Title: |
FLUORIDES EVALUATION IN SPENT POT LINER: TOXICITY CHARACTERISTIC LEACHING PROCEDURE LIMITATIONS |
| Abstract: |
The spent pot liner (SPL) is a solid waste generated in the process of aluminum production and is considered hazardous because of its fluoride and cyanide content. The purpose of this study was to analyze the SPL fraction with low cyanide coming from Aluminio Brasileiro S.A. (ALBRAS). For all the pots studied the pH of the spent pot liner (SPL) was very high and ranged from 10 to 11.80. The total fluoride content determined at high pH varied from 5.13 to 11.41 %, while the total fluoride determined in leached fluid at pH 5.0 had low values that ranged from 0.26 to 3.46 %, indicating the low solubility of waste fluorides at low pH values. With leaching fluid above pH 12, the total fluoride content varied from 6.45 to 9.39 %. The experimental results indicate that the Brazilian Standard NBR 10.004, based on leaching at pH 5.0 is not adequate for the classification of hazardous waste, since it underestimates fluoride content.
|
| Keywords: |
Fluoride, Spent potliner, Solid Waste, Ion Selective Electrode, Leaching Test.
|
| Year: |
2001
|
| Initial page: |
41
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| Final page: |
46
|
| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v9.n10.2001.43_2001.pdf |
|
|
| Author (s): |
Lavinel G. Ionescu aand Paulo Cesar Pereira das Neves
|
| Title: |
CHEMICAL ELEMENTS, ALLOYS AND MINERALS OCCURRING NATURALLY IN METEORITES |
| Abstract: |
The present article deals with some interesting aspects of meteorites, their origin, formation, impact on Earth, and their possible role in the origin of life. In particular, chemical elements, alloys, and minerals present in meteorites are considered.
|
| Keywords: |
meteorites; minerals of meteorites; natural alloys; mineralogy; origin of life..
|
| Year: |
2001
|
| Initial page: |
47
|
| Final page: |
62
|
| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v9.n10.2001.49_2001.pdf |
|
|
| Author (s): |
Olimpia Rusu, Maria Pleniceanu, Mihaela Mureseanu, Al. Popescu and Ioana Mitrache
|
| Title: |
NEW Cr(III) COMPOUNDS IN ANALYTICAL CHEMISTRY. Bi(III) CONDUCTOMETRIC DETERMINATION |
| Abstract: |
This study presents the synthesis and characterization of the complex [Bi(Rhodanine)3][Cr(NCS)4(Aniline)2]3. The new complex was analyzed by thermogravimetric, oxidation, infrared, and other spectrometric techniques and was used for the determination of bismuth in drugs. The dosage of Bi(III) in Ulcerotrat was done by conductometric titration with rhodanine and complex anions of Cr(III), respectively.
|
| Keywords: |
Cr(III) Complexes, Rhodanine, Bismuth Determination, Conductometric Titrations.
|
| Year: |
2001
|
| Initial page: |
63
|
| Final page: |
67
|
| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v9.n10.2001.65_2001.pdf |
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