JOURNAL of the Tunisian Chemical Society

serving the Research, the Education and the Industry

Addition 1,3-dipolaire du diazo - 2 propane sur des acétyléniques monoactivés dissymétriques et évolution photochimique des dimétyl-3,3 pyrazolénines formées

Written by sctunisie no comments

The synthesis of pyrazolenines derived from dissymetric monoactivated acetylenics of which the second substituant is n-alkyl has been realized stoechiometrically. This result was obtained by addition 1,3-dipolar of diazo-2 propane to the starting acetylenics. In the same way, all the photolysies of the mono-activated pyrazolenines have enabled us to get exclusively the expected mono-activated gemdimethylcyclopropene.

A. Khemiss, M. Franck-Neumann

Pages 3-12

Aspects stéréochimiques du réarrangement de Cope de monoesters d'hexadiènes-1,5

Written by sctunisie no comments

The Z/E olefinic bond ration of enol ethers obtained by Oxy-Cope rearrangement of hetero-substituted 1,5-hexadienes reveals that the reaction is not governed by the free energy change for the conversion of a substituent from the equatorial to the axial position in the chair transition state but rather by the relative thermodynamic stability of the isomers Z and E.

R. Abdelhedi, M.L. Bouguerra, J. C. Pommelet, J. Chuche

Pages 13-17

Influence de la composition du mélange réactionnel C3H6-O2 sur le comportement des catalyseurs Sn-Sb-O -

Written by sctunisie no comments

The oxidation of propylene over the Tin-Antimony oxide catalysts has been proved to be sensitive to the composition of the reactional mixture. This composition affects the stability of the catalyser during the reaction and the fonctionning of its busy centres.

B. Bejar, N. Zenaidi, A. Ghorbel

Pages 25-32

The Raman spectra of di and trimethylammonium hexachlorostannate crystals

Written by sctunisie no comments

The low frequency Raman Spectra (0 - 350 cm-1) of [(CH3)2 NH2]2 Sn Cl6 (2MHS) and [(CH3)3 NH]2 Sn Cl6 (3MHS) were recorded on single crystals at room temperature. The Spectra have been assigned on the basis of group theory analysis of vibrations and in view of the previously reported structural data of these two hexachlorostannate compouds. Their corresponding structures are derived from the Fm3m antifluorite structure.

M.H. Ben Gozlen, Y. Mlik, A. Daoud

Pages 33-37

Influence des impuretés sur le comportement électrochimique d'électrodes dans la soude 0.1 N

Written by sctunisie no comments

The fact that mixed potential of aluminum in a 0.1 N NaOH solution at 60°C is more negative when the metal is purer can be readily explained by potential v s. time plots and volumetric measurements. these are consistent with impurities behaving as microcathodes which shift the mixed potential of pure aluminum towards higher potentials, the corrosion velocity being enhanced correlatively.

E. Triki

Pages 51-54

Rss feed of the category