[en] A large number of methods for the synthesis of trialkyls phosphine oxides in general and particular trioctylphosphine oxide (TOPO) have been mentioned in the literature. The processes mostly used are those whers the compounds is synthetized by the action of metalorganic (GRIGNARD agent) on a POCl3 PCL3 and PBR3 type compound. For TOPO synthetization two processes were chosen. first are based on POCL3 and the second one on PCL3. The obtained product characterisation was done using magnetic nuclear resonance (NMR of 31P, 13C and 1H) .The comparaison of these technics have allowed to notice a total lack of both impurities and secondary phosphorus compounds

[en] A number of studies have been carried out on the separation of uranium ion by using solid-supported membranes and solvent polymeric membranes. However, the content of carrier solvent decreased and the quality of the membrane deteriorated with operation time. The present study is aimed at of the development of long-life polymeric membranes with improved stability. In this work, the cellulose triacetate(CTA) membrane containing tri-n-octylphosphine oxode(TOPO) were prepared by the phase inversion method. In this membranes, TOPO particle can act as a carrier when they are contacted with nitric acid by its gelation. The dominating factors controlling the membrane properties in the preparation process were found to be the amounts of plasticizer, CTA/TOPO ratio, and evaporation time. As a results of another experiment, the permeation rates showed constant value during a 30 day experiment, which means the excellent stability of TOPO-CTA membrane. This preliminary study has demonstrated that these membrane seems to be a promising means for separating uranium contained in aqueous solution. (Author)

[en] The present work deals with the optimization study of certain parameters necessary to the development of a novel method of purification which can be applied for tri-n-octyl phosphine oxyde in synthetic mixtures. The procedure is based on the study of process extraction -reextraction of zinc by TOPO. This method allows yields as high as 98 mass%

[en] Many methods of TOPO synthesis are known in the litterature. Neverthless, the purification methods still unknown or quite known. In this work, we have proposed to develop a new method of purification and we have used the extraction properties of TOPO. This method consist to extracting the molybdene with TOPO in acid medium

[en] The aim of the present work is the establishment of a new dosage method of trioctylphosphine oxide (TOPO). The basis of this method is colorimetry. It consist on the formation of TOPO-iron thiocynate complex which is brick-red colored, then the analysis by spectrometry UV-VIS at a length wave situated between 480 to 488nm. The number of ligands of this complex (TOPO-iron thiocynate) is determined by means of the curve which join the optic density to the SCN concentration and also to the FE-SCN complex concentration. After that, the calibration curve for the dosage of TOPO in the synthesis mixture is established

No abstract available

[en] Based on a large-scale magnification of a diagram presented by Peppard et al. (1969), the logarithms of the concentration ratios of lanthanides in aqueous phase to those in organic phase have been closely estimated for two cases. The differences of the observed values from straight lines connecting directly between La and Gd and between Gd and Lu were scrutinized in connection with the applicability of the quadratic function and with the distortion from it. In case of partitioning between 0.05M HCl and 0.3M di n-octyl phosphinic acid (benzene), two regular cycles of low and high quadratic symmetry were recognized. The features observed are explicable in terms of spatial configuration (degree of steric symmetry) of f electrons themselves, strength of directional preference of ligand-cation bonding and interaction between these two factors. Contrastingly, the system comprising di 2-ethylhexyl chloromethyl phosphonate appears to suggest the state of 4f electron subshell under very weak ligand field. (author)

[en] A review on crystal chemistry of rare earth complexes with neutral ligand - triphenylphosphine oxide - is given. Geometry, electron structure of TPPO molecules both in free (not coordinated) and in bound (coordinated) states are analysed. The revealed correlating parameters are presented. Problems of influence of complexing medium and other factors on formation of adduct structure, as well as absorption spectra and X-ray electron spectra are considered. 58 refs.; 2 figs.; 2 tabs

[en] The present work summarizes preliminary experiments dealing with the analysis of the main organophosphorus extracting agents TBP, DEHPA and TOPO widely used in hydrometallurgy and particulary in uranium one treatment. In order to ovoid the thermodegraduation processes of such compounds, an adequate combination of vaporization temperature and the carrier gas flow, i,e, the time contact of the compounds in column must be made. In this context, the present work was justly achieved in order to elaborate a only the separation but also the accurate determination of the compounds dealt with. One can remark that maintaining constant the temperature and slightly varying the flow velocity of the carrier gas, the peaks of TBP and butanol were better separated. Nevertheless, a limitation may appear when nitrogen flow is raised up to 30m1/mn. This is essentially due to the lose polarity and their analogous chemical behaviours. Thus one can conclude that such compounds can be easily determined in the ranges of 0-60% for D2EHPA, for TOPO and 24% for TBP. The determination accuracy for all compounds varies between 0.005 and 0.12%. Thus, one can conclude that the organophosphorus extracting agents such as TBP, D2EHPA and TOPO can be easily determined without previous purification. The isothermal conditions are strongly recommemded in this case because of the quickness of the technique. The secondary products resulting from the synthesis process do not affect greatly the determinations of such compounds and their accuracies

[en] In the present work, we have done an amelioration of TOPO synthesis based on the PC13, with introducing the differents microporous materials in the synthesis mixture. The catalysts used are the Faujasite Y,ZSM-5, SAPO-11. From the results of this work, we estabilished that some catalyst are performed