JOURNAL of the Tunisian Chemical Society

serving the Research, the Education and the Industry

Reaction of hydrazine and its derivatives on γ-cetonitriles

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γ-cetonitriles 1 react with hydrazine, methylhydrazine and phenylhydrazine in refluxing ethanol to lead to hydrazones 2 which are relatively stable. The cyclization of hydrazones 2 to diaminodihydropyridines 3 , needs longer heating time at higher temperature (>100 °C). The same heterocyclic compounds 3 can be synthesized directly by reacting an equimolecular mixture of hydrazines and γ-cetonitriles 1 in refluxing toluene. On an another hand, the reaction of γ-cetonitriles 1 with hydrazides, thiosemicarbazide, N-phenyl-semicarbazide and ethyl carbazate in refluxing toluene leads to the formation of a variety of triazolodihydropyridines 4. The yields of the formation of the compounds 2, 3 and 4 are good (70 - 85%).

A. Hafidh, H. Zantour, B. Baccar

Pages 771-780

Electrochemical difluoration of 1-alkylindenes

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The electrochemical fluoroacetamidation of 1-Alkylindene (CH3CN, Et3N, 3HF), gave small amounts of difluorinated products. The electrochemical difluorination in Et3N, 3HF/CH2Cl2 have been achieved, and the difluorinated became the major products formed. The diastereoisomers obtained were identified by NMR 1H, 13C and 19F.

H. Benotmane, A. Bensadat, E. Laurent, R.Tardivel

Pages 793-801

Aspartic polyacid effects on phosphate and nitrate adsorption on mercury/solution interface

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Ion phosphate adsorption (H2PO4- and HPO42-) and nitrate in the presence of polyaspartic acid was studied at the mercury -solution interface by measuring the interfacial tension depending of the potentiel. Oxyanion effect is eliminated in the presence of polyaspartic acid for the three oxyanions under study. A specific interaction between polypeptide and H2PO4- is obvious.

H. Ghabi, M. Dhahbi

Pages 803-811

Structural and physicochemical characterization of an organic dihydrogenodiphosphate: [(CH3)2 C(NH3) CH2OH]2 H2P2O7

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Chemical preparation, crystal structure, thermal behaviour and IR absorption spectrum are given for a new organic diphosphate: [(CH3)2C(NH3)CH2OH]2H2P2O7. The 2-ammonium 2-methyl propanol dihydrogenodiphosphate is monoclinic with unit cell dimensions: a=11.441(7), b=10.360(1), c=6.799(1) Å, β=98,42(1)°, V=797.2(6) Å3, ρcal.=1.351 ρmes.=1.34, µ(AgKα)= 1,635 mm-1 space group Pc and Z=2. As in all atomic arrangements including acidic diphosphate groups one observes the formation of an infinite network of anions connected by strong H-bonds [O–O=2.464 and 2.519 Å]; infinite (H2P2O7)n layers perpendicular to the a direction, for the present structure. The differential scanning calorimetric study reveals an irreversible weak phase transition. The anhydrous title compound melts and does not crystallise when cooled at room temperature but becomes a super cooled liquid. Apparently, the compound is polymerised and an amorphous phase, as confirmed by RX powder diffraction tests, is formed.

A. Gharbi, A. Jouini

Pages 813-826

Determination of diffusion coefficient of ethylendiamine in aqueous solution

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A method for determination of the molecular species diffusion coefficients in solution is proposed. This method is adapted from Stokes one and involves the unidirectional diffusion through a microporous hydrophilic membrane. It is applied to a series of near size aminated compounds. The results are compared to literature. The good agreement allows to estimate with a good accuracy the ethylenediamine (EDA) diffusion coefficient. The latter, witch is unknown in the literature, is necessary to our study on EDA "Transport-Reaction" in ion-exchange membranes.

C. Ahmed, S. Roudesli

Pages 827-838

Optimization of a liquid detergent formulation

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Plackett-Burman experimental design is applied to a five-component dishwasher liquid detergent formulation to determine which components affect five different properties of the formulation. Regression analysis and linear programming are then applied to the results of analysis in order to obtain a low cost formulation which matches or exceeds the properties of a commercially available product.

M. Moussaoui, L. Saci, T. Ahmed Zaïd, C.E. Chitour

Pages 839-846

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