Theoretical Insights Elucidate Novel Active Phosphonate Esters—Cephalosporin Antibiotics’ Intermediate

Theoretical insights elucidate a series of active phosphonate esters application in preparation of Cephalosporin antibiotics’ intermediate. The B3LYP/6-311+G(d,p) method was employed to obtain the stable equilibrium geometries including comparing to the AE-active ester. It was found that the Ethyl-aminothiazoly Loximate (AT) molecule fragment is almost planar sheet, but it is almost perpendicular to the plane of phosphoryl ester. Moreover, the calculated Mulliken atomic charge distribution and frontier molecular orbital analysis of these esters showed that the amino N atom connected to the Thiazole ring of the AT had the maximum negative charge, which suggested that this area had high molecular activity. The value of ΔEL-H was energy gap between EHOMO and ELUMO and indicated that compound 6a had high reaction activity. The theory calculation results can explain the reaction mechanism well and predict that the novel active phosphonate ester has a hopeful application prospect in preparation of Cephalosporin antibiotics’ intermediate.

Quantum Chemical Calculation on the Structures and Electronic Properties of Phosphonate Ester as Rare Earth Extractants

Molecular mechanics, molecular dynamics and semi empirical quantum chemical method have been used to study the geometric and electronic structures of six phosphonate ester as rare earth extractants. The results show that the phosphorus atom exhibits sp 3 hybridization. The structures of the extractants are determined by the repulsion of the hydrocarbon groups. In the extractants that have two 2 ethyl hexyl groups, one 2 ethyl hexyl extends straight, and the other extends twistily. When the number of oxygen atom decreases, the negative charge of the phosphoryl oxygen atom increases, but the negative charge of oxygen atom and the positive charge of hydrogen of the hydroxyl group decreases, and the energies of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital(LUMO) increase. The energies of the occupied frontier orbitals are close to each other.

Synergistic extraction of praseodymium with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester and 8-Hydroxyquinoline

The synergistic extraction of Pr^3＋ from hydrochloric medium using mixture of 2-ethylhexyl phosphonic acid mono- 2-ethylhexyl ester （P507, HL） and 8-Hydroxyquinoline （HQ） in heptane was investigated. The effect of equilibrium of aqueous acidity on extraction of Pr^3＋ was discussed. The effect of extractant concentraction, different diluents, equilibrium time and acetate ion concentration oil extraction reaction were also studied. With a method of double-logarithmic slope, composition of the extracted species on 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester and 8-Hydroxyquinoline was derived. The result shows that the synergistic extraction system not only overcomes emulsification of 8-Hydroxyquinoline, but also shows perfect capacity of synergistic extraction. The largest synergistic enhancement factor can be calculated to be 5.49 at pH 3.6 for Pr^3＋.

Novel Phosphonoacetic Acid Derivatives.Synthesis of N-(Ethoxycarbonylmethylphosphonyl)-α-Amino Esters and-α-Amino Phosphonic Acid Esters and Their Bioactivities

A series of novel phosphonoacetic acid derivatives, N-(ethoxycarbonylmethy-ethoxyphosphonyl)-α-amino acid esters and α-amino phosphonates, were synthesized via the reaction of the corresponding phosphonyl chloride with amino acid ester hydrochlorides or amino phosphonates in the presence of a base. The preliminary bioassay shows that some compounds show significant anti-viral activity against tobacco mosaic virus (TMV)

Extraction Separation of Scandium，Iron and Lutetium with Isopropyl Phosphonic Acid Mono（1－hexyl－4－ethyl）OctylEster

The extraction and stripping of scandium from its sulfate solutions by isopropyl phosphonic acid mono (1-hexyl-4-ethyl) octyl ester (PT-2, HL) diluted with n-hexane are reported. A high efficiency of separation between scandium, iron and lutetium can be achieved by controlling aqueous acidity. Different mechanisms of Sc3+ with PT-2 in various acid range have been proposed.At lower aqueous acidity, it is a cation exchange reaction, while at higher acidity. a solvation reaction was ascertained. Its IR and NMR spectra have been discussed. The effect of temperature on extraction of Sc3+ was observed and thermodynamic functions were calculated.

Study on transport of Dy(Ⅲ) by dispersion supported liquid membrane

The transport of Dy（III） through a dispersion supported liquid membrane （DSLM） consisting of polyvinylidene fluoride membrane （PVDF） as the liquid membrane support and dispersion solution including HCI solution as the stripping solution and 2-ethyl hexyl phosphonic acid-mono-2-ethyl hexyl ester （PC-88A） dissolved in kerosene as the membrane solution, was studied. The effects of pH value, initial concentration of Dy（III） and different ionic strength in the feed phase, volume ratio of membrane solution and stripping solution, concentration of HCl solution, concentration of carrier, different stripping agents in the dispersion phase on transport of Dy（III） were also investigated, respectively. As a result, when the concentration of HCI solution was 4.0 mol/L, concentration of PC-88A was 0.10 mol/L, and volume ratio of membrane solution and stripping solution was 40：20 in the dispersion phase, and pH value was 5.0 in the feed phase, the transport effect of Dy（III） was the best. Ionic strength had no obvious effect on transport of Dy（III）. Under the optimum condition studied, when initial concentration of Dy（III） was 0.8×10^-4 mol/L, the transport rate of Dy（III） was up to 96.2% during the transport time of 95 rain. The kinetic equation was developed in terms of the law of mass diffusion and the theory of interface chemistry. The diffusion coefficient of Dy（III） in the membrane and the thickness of diffusion layer between feed phase and membrane phase were obtained and the values were 1.99×10^-7 m^2/s and 15.97 μm, respectively. The results were in good agreement with experimental results.

Separation and recovery of rare earth from waste nickel-metal hydride batteries by phosphate based extraction-precipitation

A novel type of extraction-precipitation strategy based on phosphate was developed to recover rare earth(RE,i.e.,La,Ce,Nd,and Pr)from waste nickel-metal hydride(NiMH)batteries.This method does not require saponification and organic solvents.The novel phosphates,i.e.,dibenzyl phosphate(DBP),diphenyl phosphate(DPP),triphenyl phosphate(TPP)were studied as extraction-precipitants.DBP has high precipitation efficiencies for RE^(3+),which can reach 97.84%,100%,100%and 99.77%,respectively.In addition,the precipitation efficiencies of Mn^(2+),Co^(2+)and Ni^(2+)are less than 1.75%.DBP-RE has the largest particle size(D10=52.6μm,D50=135.35μm,D90=296.08μm),which is much larger than the precipitations formed by NH_(4)HCO_(3),H_(2)C2O_(4),CaO and MgO.The larger precipitation particle sizes contribute to improving the solid-liquid separation efficiency.With 3 mol/L hydrochloric acid,the stripping efficiency of DBP-RE reaches 98.60%,and the purity of recovered RE is 99.85%.The regenerated DBP can be directly used for the recycling extraction.Therefore,the novel extraction-precipitation strategy is a green and sustainable separation method.

Study on supported combined liquid membrane containing HEH(EH)P and HNO_3 for trivalent gadolinium transfer

A novel kind of supported combined liquid membrane （SCLM） has been studied for the Gd（IIl） transfer. SCLM contained polyvinylidene fluoride membrane （PVDF） as the liquid membrane support and renewal solution including HNO3 solution as the stripping solution and 2-ethyl hexyl phosphonic acid-mono-2-ethyl hexyl ester （HEH（EH）P） as the carrier dissolved in kerosene. The mixed solution of carrier and kerosene was membrane solution. The optimum transport conditions of Gd（III） were that concentration of HNO3 solution was 4.00 tool/L, concentration of carrier was 0.16 mol/L, and volume ratio of membrane solution to stripping solution was 30：30 of the renewal phase, and pH value was 4.80 of the feed phase. Under the optimum condition studied, when initial concentration of Gd（III） was 1.00 × 10^-4 mol/L, the transfer rate of Gd（III） was 96.8% during 130 min.

Modeling of Ce（IV） transport through a dispersion flat combined liquid membrane with carrier P507

A mathematical model for the transport of Ce （IV） from hydrochloric acid solutions through dispersion flat combined liquid membrane （DFCLM） with contain 2- ethyl hexyl phosphonic acid-mono-2-ethyl hexyl ester （P507） as the carrier, dissolved in kerosene as the membrane solution have been studied. This process of facilitated transport, based on membrane technology, is a variation on the conventional technique of solvent extraction and may be described mathematically using Fick＇s second law. The equations for transport velocity are derived considering the diffusion of P507 and its metallic complexes through the liquid membrane. In this work, the system is considered to be in a transient state, and chemical reaction between Ce（IV） and the carrier to take place only at the solvent-aqueous interfaces. Model concentration profiles are obtained for the Ce（IV）, from which extraction velocities are predicted. The experimental and simulated Ce（IV） extractions showed similar tendencies for a high Ce （IV） concentration and acidity case.The model results indicate that high initial Ce（IV） concentrations and acidity both have detrimental effects on Ce（IV） extraction and stripping. The diffusion coefficient of Ce（IV） in the membrane and the thickness of diffusion layer between feed phase and membrane phase are obtained and the values are 6.31 × 10-8m2·s-1 and 31.2 μm, respectively. The results are in good agreement with experimental results.