In the usual experimental conditions, reaction of saturated, phenylic and allylic organometallic compounds with α-β ethylenic imidates give exclusively the addition-1,4 products with good yields.
M.L. Efrit, B. Hajjem, B. Baccar.
Three new products have been prepared by oxidation of 19 epi heyneanine 1. These are: 3 oxo 19 epi heyneanine 3; 7 hydroxy-indolenine 19 epi heyneanine 5 and 7 hydroxy-indolenine 19 epi heyneanine N-oxide 6.
R. Jarraya, M. Damak.
The reduction of Rh (III) and In (III) by means of carbon monoxide at a moderate temperature leads to the formation of complexes of definite dicarbonyles of rhodium or iridium. The oxidation of halogeno methane by these complexes leads to an M-R bond which reacts with carbon monoxide to produce an acyl bond. The complex transforms through a reducing elimination of the acetyl halogen in the presence of methyl acetate, to form acetic anhydride.
B. Elleuch, Y. Ben Taarit, P. Gelin.
The characterization of the interface polymer/solid is studied by 1H and 13C NMR. One of the main objectives of this work is to determine the disposition of monomer units near the surface and their concentration. Utilization of different techniques such as multipulse sequences, MAS with variable temperature, observation of the relaxation function of different nuclei, Cross polarisation, allow to propose some approach methodology. The example chosen to illustrate the techniques is the poly (ethylene) oxide grafted on silica. A coherent agreement is obtained for the physical parameter which describes the monomer unit concentration on the surface, by two independent techniques namely pseudo-solid echo and MAS, taking into account the molecular weight and the temperature as pertinent parameters.
Cellulose acetate membranes are prepared by phase inversion process. For these membranes, the most required characteristics are a good permeation water rate, a high salt rejection rate and high thermic and chemical properties. We proceeded to a synthetic review of the most known preparation processes and studied the influence of different parameters on the cellulose acetate membranes: the casting solution constitution (polymer. solvent, non-solvent and additives) and the preparation conditions (atmospheric humidity, evaporation time, coagulation bath, and heat and chemical treatment).
E. Ferjani. S. Bougacha, M. Djedidi, S. Roudesli.