A5042777854- Radioactive element chemistry and processing
- Chemical Synthesis and Characterization
- Extraction and Separation Processes
- Lanthanide and Transition Metal Complexes
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Nuclear Materials and Properties
- Analytical chemistry methods development
- Metal complexes synthesis and properties
- Organometallic Complex Synthesis and Catalysis
- Inorganic and Organometallic Chemistry
- Crystallography and molecular interactions
- Magnetism in coordination complexes
- Radioactive contamination and transfer
- Ionic liquids properties and applications
- Inorganic Chemistry and Materials
- Organometallic Compounds Synthesis and Characterization
- Porphyrin and Phthalocyanine Chemistry
- Nuclear materials and radiation effects
- Electrochemical Analysis and Applications
- Radiation Detection and Scintillator Technologies
- Microbial Community Ecology and Physiology
- Chemical Thermodynamics and Molecular Structure
- Molecular Sensors and Ion Detection
- Mine drainage and remediation techniques
Bhabha Atomic Research Centre
2015-2024
Homi Bhabha National Institute
2018-2024
Lawrence Berkeley National Laboratory
2020
University of Mumbai
2014-2020
Colorado State University
2017
Toowoomba Hospital
2016
University of Nevada, Las Vegas
2012
University of Delhi
2005
National University of Singapore
2004
Raman Research Institute
1998-2001
The conventional concept of selective complexation actinides with soft donor ligands (either S or N donor) has been modified here through exploiting the concept, "intra-ligand synergism", where a hard atom, such as oxygen preferentially binds to trivalent [An(iii)] compared valence iso-electronic lanthanides [Ln(iii)] in presence another centre. We have theoretically predicted selectivity 1,10-phenanthroline-2,9-dicarboxylamide towards Am(iii) ion density functional calculations....
Abstract Pyrite (FeS 2 ) is the most abundant sulfide mineral on Earth and represents a significant reservoir of reduced iron sulfur both today in geologic past. In modern environments, oxidative transformations pyrite other metal sulfides play key role terrestrial element partitioning with broad impacts to contaminant mobility formation acid mine drainage systems. Although aerobic micro‐organisms oxidation under acidic‐ pH conditions well known, date there very little known about capacity...
An N-pivot diglycolamide extractant (DGA-TREN) was synthesized for the first time and its complexation behaviour studied towards trivalent lanthanide/actinide ions. The solvent extraction studies suggested a unique selectivity reversal in of actinides versus lanthanides which observed performing an ionic liquid vis-à-vis molecular diluent tripodal TREN-based ligand vs. (T-DGA) may have great significance radioactive waste remediation. nature bonding to Eu(3+) ion investigated by EXAFS as...
Optimized complexes of Lu<sup>3+</sup>with TMDGA in 1 : 1, 2 and 3 stoichiometric ratios plots theoretically calculated stepwise binding energy.
The separation of trivalent actinides and lanthanides is a challenging task for chemists because their similar charge chemical behavior. Soft donor ligands like Cyanex-301 were found to be selective the over lanthanides. Formation different extractable species Am(3+) various (viz. La(3+), Eu(3+), Lu(3+)) was explained on basis relative stabilities as compared corresponding trinitrato complexes calculated using density functional method. Further, metal-ligand complexation energy segregated...
Abstract Separation behavior of Am3+ and Eu3+ was studied from aqueous nitrate medium using the “soft‐donor” Cyanex‐301 (bis(2,4,4‐trimethylpentyl) dithiophosphinic acid) in toluene as extractant. The separation factor (S.F.=DAm/DEu) value 5000 (obtained with pure Cyanex‐301) increased about eight times when a binary mixture N‐donor ligands (such 2,2′‐bipyridyl (bipy) or 1,10‐phenanthroline (phen)) used S.F. values >40,000 are highest reported to date. Nitrate ion played an important role...
Abstract The separation behavior of trivalent actinides and lanthanides from aqueous nitrate medium has been investigated using purified commercial Cyanex® 301 [bis(2,4,4‐trimethylpentyl)dithiophosphinic acid] in toluene by solvent extraction as well chromatography. studies were carried out Am3+ Eu3+ the representative actinide lanthanide ion, respectively. stoichiometry extracted species determined slope‐analysis method was Am(A)3 Eu(A)2(NO3), when HA (Cyanex 301) concentration <0.3 M. At a...
The radiolytic stability of a promising extractant for actinide partitioning from high-level radioactive liquid waste, namely N,N,N',N'-tetraoctyl diglycolamide (TODGA) was investigated in the presence several phase modifiers, viz. N,N-dihexyloctanamide (DHOA), tri-n-butyl phosphate (TBP), 1-decanol, and iso-decanol dissolved n-dodecane. distribution ratio Am(III) decreased with increased radiation dose studied up to 1000 kGy. Nevertheless, all compositions extractants showed fairly high...
A multiple diglycolamide (DGA)-containing ligand having four DGA arms tethered to a tetraaza-12-crown-4 ring, viz. 2,2′,2′′,2′′′-(((1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrayl)tetrakis(2-oxoethane-2,1-diyl)) tetrakis (oxy)) tetrakis(N,N-dioctylacetamide) (T12C4ODGA), was synthesized and evaluated for the extraction of different actinide lanthanide ions, Am3+, Eu3+, Pu4+, Np4+, UO22+. The efficiency present found be highest reported so far, more specifically trivalent metal ions Am3+ when...
Two types of Cs+ ion-selective crown ether–Nafion composite membranes have been prepared. In one case, the dibenzo-21-crown-7 (DB21C7) has incorporated uniformly in form Nafion-117 membrane varying molar ratio with respect to Cs+, and other driven loading DB21C7 confined (ion gating) a very small thickness (25 μm) from surfaces membrane. The surface confinement ion-gated studied by energy dispersive X-ray spectroscopy secondary ion mass spectrometry. cation (Cs+/Na+) transport properties...
Extraction of actinide (Pu4+, UO22+, Am3+) and lanthanide (Eu3+) ions was carried out using different diglycolamide (DGA) ligands with systematic increase in the alkyl chain length from n-pentyl to n-dodecyl. The results show a monotonous reduction metal ion extraction efficiency increasing this becomes even more prominent case branched (2-ethylhexyl) substituted DGA (T2EHDGA) for all studied. Steric hindrance provided by groups has strong influence controlling behavior DGAs. distribution...
The work describes a novel and cleaner approach of electrodriven selective transport Cs from simulated nuclear waste solutions through cellulose tri acetate (CTA)/poly vinyl chloride (PVC) based polymer inclusion membrane. cation together with the use highly Cs+ hexachlorinated derivative cobalt bis dicarbollide, allows to achieve separation high concentration Na+ other fission products in solutions. selectivity has been studied using radiotracer technique as well atomic emission...
Mutual separation of trivalent actinide (An(3+)) and lanthanide (Ln(3+)) using several soft (N) donor ligands (bis(5,6-dialkyl-1,2,4-triazinyl)pyridine (R-BTP)) is attempted for the first time in room temperature ionic liquid (RTIL) medium. The results indicate a spectacular enhancement selectivity as compared to that molecular diluents with factor (S.F.) >3000 Am(3+) over Eu(3+) methyl derivative (Me-BTP) RTIL medium [C(n)mim]·[NTf2] (where n = 2, 3, 4, 6 or 8). Such high S.F. value has...
The complexation of three DGA-functionalized calix[4]arenes were studied with Eu<sup>3+</sup> ion by spectroscopy and DFT calculations.
Solvent extraction and complexation of Am<sup>3+</sup> Eu<sup>3+</sup> were studied using HONTA.
A novel tripodal diglycolamide ligand containing a triazamacrocycle center (2,2',2''-(((1,4,7-triazonane-1,4,7-triyl)tris(2-oxoethane-2,1-diyl)) tris(oxy)) tris( N, N-dioctylacetamide), abbreviated as T9C3ODGA) was synthesized and characterized by conventional techniques. The resulted in efficient extraction of actinide/lanthanide ions yielding the trend: Eu3+ > Pu4+ Am3+ NpO22+ UO22+ Sr2+ Cs+. Similar to most other (DGA) ligands, preferentially extracted compared Am3+; separation factor (...
Combined effect of marginal Am 3+ selectivity T2EHDGA and Cm SO 3 PhBTP is exploited for the improvement in Am/Cm separation.