Dicyclohexylphosphinic acid (DcyHPA) and some of its metal complexes with lanthanides (La, Ce, Gd, Sm and Nd) and actinides (U and Th) were prepared and subsequently the structural composition was elucidated. The single crystal XRD data and theoretical analysis revealed that the ligand (DcyHPA) exists as a dimer in solid state. DcyHPA showed dual nature for the extraction of U(VI), Th(IV) and Am(III) from nitric acid medium i.e. at lower acidity, the ligand behaves as an acidic extractant and extracted the metal through cation exchange mechanism while solvation mechanism played a major role for extraction at higher acidity. Additionally, density functional theory (DFT) calculations were demonstrated to understand the electronic structure of thorium-DcyHPA metal complex formed during the extraction process. © 2016 Elsevier Ltd

Akella Sivaramakrishna

Department of Chemistry

School of Advanced Sciences

Vellore Campus

Sabareesh V

Centre for Bio-Separation and Technology

Goud E.V

Das D

Vijayakrishna K

Gopakumar G

Brahmmananda Rao C.V.S

Lone M.Y

Jha P.C.

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Polyhedron

A novel phosphoramidate-functionalized polymeric resin was synthesized by anchoring diethyl (3-(1H-imidazol-1-yl)propyl)phosphoramidate group with chloromethylated polystyrene divinylbenzene resin. The grafted resin was characterized using elemental analysis, Fourier transform infrared, solid-state 31P NMR energy-dispersive X-ray spectroscopies, and thermogravimetric analysis. The surface morphology of the functionalized resin was investigated using scanning electron microscopy and the surface area was measured with Brunauer–Emmett–Teller analysis. Sorption affinities of the functionalized resin towards actinides such as Th(IV) and U(VI) were determined under various concentrations of nitric acid solution (0.01–6 mol L−1). Desorption of the actinides from the loaded resin was performed using a solution of 0.01 mol L−1 nitric acid. Reusability of the grafted resin was studied over various successive cycles and the stability of the functional groups on the synthesized resin was monitored using various analytical techniques. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry

Polymer International

Phosphoramidate-functionalized Merrifield resin: synthesis and application in actinide separation

To delineate the effect of P–C bond of phosphorous esters on the extraction of actinides, diverse organophosphorus esters (trihexyl phosphonate (THP), dihexylhexyl phosphonate (DHHP), hexyldihexyl phosphinate (HDHP) and trihexylphosphine oxide (THPO)) were synthesized and spectroscopically characterized. The physical properties such as density, viscosity are reported in subsequent sections. The extraction behaviour of the ligands were evaluated for U(VI), Th(IV) and Am(III), as well as acid uptake as a function of nitric acid ranging from 0.01–6 M. Distribution ratios for U(VI), Th(IV) and Am(III) indicate a large difference in solvent strength among these compounds. Replacement of P–O–C group by P–C group i.e. introduction of electron donating group greatly increases the solvent strength. The P=O stretching frequency can be correlated with the solvent strength of these compounds, and the conclusions are further supported by density functional theory calculations. © 2018 Elsevier B.V.

Journal of Molecular Liquids

Trihexyl phosphate to trihexyl phosphine oxide: Diverse effect on extraction behavior of actinides

Tri-n-butyl phosphate (TBP) is most extensively used extractant in the nuclear fuel cycle. The present work investigates the effect of substituents and their role in the basicity of organophosphorus extractant on the uptake of actinides. In this connection, we have synthesized six different analogues of TBP by altering one of its butoxy group. The synthesized TBP derivatives were well characterized and evaluated for their solvent extraction behavior towards U(VI), Th(IV), Pu(IV) and Am(III), as well as acid uptake as a function of nitric acid ranging from 0.01 to 6 M and the data provides the comparison of their extraction behavior with that of 30% (1.1 M) tri-n-butyl phosphate under identical conditions. It was observed that distribution coefficient values strongly depend on the nature and size of the substituents. The presence of electron donating groups enhances the uptake of the actinides and the distribution coefficient values were significantly larger as compared to that of TBP. In addition, the effect of sodium nitrate on the extraction of uranium and enthalpy of extraction were also studied and revealed that the extraction process was exothermic. © 2017 Elsevier B.V.

Inorganica Chimica Acta

Extraction of actinides by Tri-n-butyl phosphate derivatives: Effect of substituents

Extraction behavior of some selected actinides like U(VI), Th(IV), and Am(III) was investigated with three different H-phosphine oxides, viz. diphenyl hydrogen phosphine oxide (DPhPO), dihexyl hydrogen phosphine oxide (DHePO) and diphenyl phosphite (DPP). The H-phosphine oxides exhibited a dual nature towards the extraction of actinides where the ligand not only extracts the metals by cation exchange but also by coordination with the phosphoryl group at lower and higher acidic concentrations, respectively. Among all ligands employed, DPhPO showed highest extraction with actinides with a substituent dependent trend as follows: DPhPO &gt; DHePO &gt; DPP. This trend emphasizes the importance of substituents around the phosphine oxide towards their extraction of actinides. The coordination behavior of DPhPO was studied by investigating its corresponding complexes with Th(NO3)4 and UO2(NO3)2. The metal complexes of these actinides were characterized using FT-IR, 1H and 31P NMR spectroscopic techniques. Density Functional Theory (DFT) calculations were also performed to understand the electronic and geometric structure of the ligand and the corresponding metal complexes. © 2017 Informa UK Limited, trading as Taylor &amp; Francis Group.

Journal of Coordination Chemistry

Extraction and coordination behavior of diphenyl hydrogen phosphine oxide towards actinides

Some selected aminophosphine oxides (AmPOs) and their corresponding La(iii) and Th(iv) complexes are synthesized and analyzed by FT-IR, 1H-NMR, 31P{1H}-NMR, elemental analysis and TGA data.

RSC Advances

Function of substituents in coordination behaviour, thermolysis and ligand crossover reactions of phosphine oxides

The extraction behavior of U(vi) &amp; Am(iii) with di-n-alkyl phosphine oxides (DAPOs) was investigated. DAPO behaves like an acidic extractant at low acidity and at higher acidity they extracted via cation exchange mechanism.

Experimental and theoretical studies on extraction behavior of di-n-alkyl phosphine oxides towards actinides

Some aminophosphine oxides (AmPOs), (R1)(R2)(R 3)P=O [R1=R2=R3= HNCH 2CH=CH2; R1= R2=Ph, R 3=HNCH2CH=CH2; R1=R 2=R3=HNNMe2; R1=R2=Ph, R3=HNNMe2; R1=R2=R3= NC4H8O; R1= R2=Ph, R3= NC4H8O], have been synthesized. The coordination chemistry of these AmPOs is studied with La(III), Th(IV), and U(VI) salts. The products are characterized by various analytical and spectroscopic techniques, and the thermal properties of the ligands and their complexes examined. The TGA data for these compounds show different decomposition temperatures, as well as thermal stability of the metal complexes. Comparisons are made among different ligands on their selective complexing ability towards some chosen metal salts. Mulliken population analysis shows that the basicity of P=O of ligand increases with an increase in the number of P-bonded amino groups. © 2013 Taylor &amp; Francis.

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Publisher	Data powered by TypesetElsevier BV
ISSN	02775387
Open Access	No