- A high-performance impregnated resin for recovering thorium from radioactive rare earth waste residue
-
A novel impregnated resin with n-octyl diphenyl phosphate (ODP-IR) was developed for the separation of thorium from leaching solution of rare earth (RE) waste residue. Nitrogen adsorption, FT-IR spectra, scanning electron microscopy and energy dispersive spectrometer were conducted for the characterization of ODP-IR. Uptake of ODP-IR for Th4?+ was significantly affected by changing HNO3 concentration. The adsorption data were fitted well with pseudo-second-order rate model. Thermodynamic parameters for the adsorption of Th4?+ were calculated and discussed. The adsorption was fitted well with the Langmuir isotherm model than Freundlich isotherm model. ODP-IR was repeatedly used five times without obvious loss for Th4?+ adsorption, indicating that the adsorbent was stabilized. The ODP-IR was successfully used to separate Th from RE and Fe using the feed solution from ion-adsorption type RE waste residue, which revealed potentials in the fields of RE resource utilization, radioactive contamination treatment and nuclear fuel preparation.
- Qiu, Sen,Li, Shun,Dong, Yamin,Su, Xiang,Wang, Yanliang,Shen, Yinglin,Sun, Xiaoqi
-
-
Read Online
- Recyclable copper catalyst on chitosan for facile preparation of alkyl/aryl mixed phosphates via deaminated esterification between diphenylphosphoryl azides and aliphatic alcohols
-
An efficient methodology was established for the preparation of alkyl/aryl mixed phosphates under aerobic conditions promoted by a easily recoverable heterogeneous catalyst. This highly active copper catalyst was obtained by directly mixing of copper precursor with chitosan solution, followed by a simple work-up process. In this catalytic system, different phosphoryl azides and aliphatic alcohols were employed to generate desired products in moderate to excellent yields with good functional group tolerance. This protocol provided a practical application of the chitosan supported heterogeneous copper catalyst towards a novel P–O bond formation.
- Hao, Qingqing,Hong, Qian,Jiao, Lin-Yu,Li, Zhuo,Liu, Shanshan,Ma, Xiao-Xun,Ning, Zi-Hui,Sun, Ming,Xu, Long,Zhang, Ze
-
-
- Direct aerobic oxidative esterification and arylation of P(O)-OH compounds with alcohols and diaryliodonium triflates
-
Copper-catalyzed aerobic oxidative esterification of P(O)-OH compounds is achieved using alcohols as efficient esterification reagents, giving the expected products with good to moderate yields. Furthermore, it is shown that the arylation of P(O)-OH compounds proceeds efficiently to produce the corresponding products via the treatment of diaryliodonium triflates under mild reaction conditions. It is a simple way to produce a broad spectrum of functionalized phosphinates, phosphonates, and phosphates from basic starting materials with good to excellent yields. The protocol is convenient for practical application. A plausible mechanism has been proposed for the reaction.
- Xiong, Biquan,Feng, Xiaofeng,Zhu, Longzhi,Chen, Tieqiao,Zhou, Yongbo,Au, Chak-Tong,Yin, Shuang-Feng
-
p. 537 - 543
(2015/04/14)
-
- An improved method for Lewis acid catalyzed phosphoryl transfer with Ti(t-BuO)4
-
Several inorganic esters have been evaluated as phosphoryl transfer catalysts. Of these, Ti(t-BuO)4 was found to be the most effective catalyst giving excellent yields of the desired phosphate esters. The loading of the catalyst could be reduced to a little as 5 mol % for a majority of substrates with no loss in the yield of product. This methodology is significantly more versatile than using TiCl4 and is suitable for the phosphorylation of more complex carbohydrates and molecules of biological interest.
- Jones, Simon,Selitsianos, Dimitrios,Thompson, Kate J.,Toms, Steven M.
-
p. 5211 - 5216
(2007/10/03)
-
- A simple and effective method for phosphoryl transfer using TiCl4 catalysis
-
(graph presented) A number of Lewis acids have been evaluated as catalysts for the phosphoryl transfer, the most efficient being TiCl4. Application of this methodology to the phosphorylation of a number of representative target alcohols is presented.
- Jones, Simon,Selitsianos, Dimitrios
-
p. 3671 - 3673
(2007/10/03)
-
- REACTIONS DE WITTIG-HORNER ET DE TRANSESTERIFICATION EN UNE OPERATION PAR ACTIVATION ANIONIQUE DE LIAISONS C-H ET O-H EN MILIEU HETEROGENE CARBONATE DE POTASSIUM/ALCOOL
-
The Wittig-Horner reaction carried out in various alcohols is accompanied by transesterification of the alkyl radical of the α,β-ethylenic ester formed.The occurrence of these two reactions in the same reaction medium is affected by the behavior of: i) the alcohol (solvent and reagent), ii) potassium carbonate (reagent and catalyst).The propensity for the two reactions to occur was found to depend on the polarity of the alcohol.Protic alcohols speeded both the Wittig-Horner and the subsequent transesterification reaction.Both reactions were quantitative despite the use of non-stoichiometric amounts of potassium carbonate.Regeneration in situ of the solid base observed in aprotic medium was markedly enhanced under these reaction conditions.The mechanism proposed for these two reactions incorporates this regeneration process.
- Mouloungui, Z.,Elmestour, R.,Delmas, M.,Gaset, A.
-
p. 1219 - 1232
(2007/10/02)
-