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11.
Plutonium from acidic waste solutions has been recovered quantitatively using tri-n-octylamine (TnOA) in xylene and americium using a mixture of octylphenyl-N-N- diisobutylcarbamoylmethylphosphine oxide (CMPO) and TBP in dodecane by extraction and extraction chromatographic methods. The Pu ( IV ) TnOA species extracted into the organic phase from higher nitric acid concentrations has been confirmed as (R(3)NH)(2)Pu(NO(3))(6) (where R(3)N = TnOA by employing slope analysis as well as spectrophotometric studies. 相似文献
12.
Crowe MC Kapoor RN Cervantes-Lee F Párkányí L Schulte L Pannell KH Brodbelt JS 《Inorganic chemistry》2005,44(18):6415-6424
Electrospray ionization (ESI) quadrupole ion trap mass spectrometry (QIT-MS) and collisionally activated dissociation (CAD) were used to evaluate the rare-earth binding properties of two hydrophobic carbamoylmethylphosphine oxide (CMPO) ligands, the normal bidentate variety, (t-BuC6H4)2P(O)CH2C(O)N(i-Bu)2 (A), a new potentially tridentate extractant, (t-BuC6H4)2P(O)CH[CH2C(O)N(i-Bu)2]C(O)N(i-Bu)2 (B), and tributyl phosphate. The mass spectral results obtained from analysis of 1% HNO3/methanol solution containing the ligands and dissolved lanthanide salts reveal that the favorable stoichiometries of the ligand/metal/nitrate complexes are 2:1:2 for the bidentate ligand A, 1:1:2 for the tridentate ligand B, and 3:1:2 for the monodentate tributyl phosphate. These observed stoichiometries correlate with the number of available binding sites on each ligand as well as with potential steric effects. Energy-variable collisionally activated dissociation experiments showed that for the 2:1:2 complexes involving ligand A or B, as the ionic radius of the bound metal decreased, the removal of nitric acid required less energy and resulted in less extensive spontaneous solvent coordination. This experimental trend suggests that, as the ionic radius of the lanthanide ion decreases, a pair of the carbamoylmethylphosphine ligands is able to more completely solvate the bound metal ion thereby weakening the nitrate-metal interaction. 相似文献
13.
Thomas S Biswas N Venkateswaran S Kapoor S Naumov S Mukherjee T 《The journal of physical chemistry. A》2005,109(44):9928-9934
The surface-enhanced Raman scattering (SERS) studies of 5-amino tetrazole (5AT), a tetrazole derivative, in aqueous silver sol at pH approximately 9 and on deposited colloidal silver films were carried out and compared with the normal Raman spectrum of the molecule. The experimentally observed Raman bands along with their corresponding infrared bands were assigned based on the results of density functional theory (DFT) calculations. The significant changes evidenced between the SERS and the normal Raman spectra combined with the theoretical data obtained for Ag-5AT system demonstrated that the molecule is adsorbed on colloidal Ag particles through the lone pair of electrons of the nitrogen atom. The contribution of the chemical mechanism for the SERS enhancement was proved by the behavior of the electronic absorption spectrum of the Ag colloid upon addition of 5AT. This is further supported by the theoretical calculations that show that the favorable interaction of the frontier orbitals localized on Ag(+) and the negatively charged nitrogen from the tetrazole ring leads to the formation of the stable (up to 130 kJ mol(-1)) charge-transfer complex. The orientation of the adsorbed species with respect to the metal surface was also predicted by applying the "surface selection rule". In addition, the feasibility of the formation of the polymeric species has also been discussed. 相似文献
14.
Medha Rele Sudhir Kapoor Shweta Hedge Sergej Naumov Tulsi Mukherjee 《Research on Chemical Intermediates》2006,32(7):637-645
Many photo-physical studies have been reported for the detection of Hg2+ ions. Here we present the effect of Hg
2
2+
ions on the absorption and fluorescence of indole-2-carboxylic acid (I2C). Experimental evidence, supported by density functional
theory B3LYP/LANL2DZ/PCM, for the formation of a I2C-Hg
2
2+
complex, is reported for the first time. It was observed that I2C forms a ground-state complex with Hg
2
2+
ions in a ratio of 3:1. The possibility of I2C to be used as a selective novel chemical sensor for the spectrophotometric
detection of mercurous ions is described. 相似文献
15.
Jesik R Abramov V Antipov Y Baldin B Crittenden R Dauwe L Davis C Denisov S Dyshkant A Dzierba A Glebov V Goldberg H Gribushin A Koreshev V Krider J Krinitsyn A Li R Margulies S Marshall T Martin J Mendez H Petrukhin A Sirotenko V Smith P Solomon J Sulanke T Sulyaev R Vaca F Zieminski A Blusk S Bromberg C Chang P Choudhary B Chung W de Barbaro L Dlugosz W Dunlea J Engels E Fanourakis G Ginther G Hartman K Huston J Kapoor V Lirakis C Lobkowicz F Mani S Mansour J Maul A Miller R Oh B Pothier E 《Physical review letters》1995,74(4):495-498
16.
A. Karnik S. Kailas A. Chatterjee P. Singh A. Navin D. C. Biswas D. M. Nadkarni A. Shrivastava S. S. Kapoor 《Zeitschrift für Physik A Hadrons and Nuclei》1995,351(2):195-198
The fission fragment angular distributions for the system12C +232Th have been measured in the energy range 0.97<>c.m./VB<1.22. the=" measured=" anisotropies=" have=" been=" compared=" with=" the=" predictions=" of=" the=" standard=" saddle=" point=" statistical=" model,=" using=" the=" second=" moment=" of=" the=" compound=" nucleus=" spin=" distribution=">1.22.>l2 deduced from a Wong model fit to the fission excitation function. While the measured anisotropies agree with the standard saddle point statistical model for Ec.m./VB>1.05, they are abnormally large at lower energies. This is also true for the existing measurements of16O and19F +232Th systems. Since for this system pre-equilibrium fission contributions are not expected, this anomaly indicates strong channel coupling effects leading to an increase in l2 at sub-barrier energies.The authors thank Drs. R.K. Choudhury and A. Saxena for useful discussions, Dr. R.J. Singh for making the thorium target and the Pellectron operation staff for excellent operation of the machine. 相似文献
17.
18.
Alverson G Baker WF Ballocchi G Benson R Berg D Blusk S Bromberg C Brown D Carey D Chand T Chandlee C Choudhary BC Chung WH de Barbaro L DeSoi W Dlugosz W Dunlea J Easo S Engels E Faissler W Fanourakis G Ferbel T Garelick D Ginther G Glass G Glaubman M Gutierrez P Hartman K Huston J Johnstone C Kapoor V Kourbanis L Lanaro A Lirakis C Lobkowicz F Lukens P Mani S Maul A Mansour J Miller R Nelson CA Oh BY Orris D Pothier E Prebys E Rajaram BM Roser R Ruddick K Shepard P Shivpuri RK Sinanidis A 《Physical review D: Particles and fields》1993,48(1):5-28
19.
Polygonal (mainly triangular) silver nanoprisms were prepared by reducing silver perchlorate in formamide in the presence of polyethylene glycol (PEG) at room temperature. The reduction of silver ions by formamide leads to the deposition of arrays of triangular shaped silver nanoparticles on the glass walls of the container, accompanied by evolution of CO2 gas. In the presence of poly(N-vinyl-2-pyrrolidone) (PVP) and PEG (1:1), both nanospheres and nanoprisms are formed. 相似文献
20.
The novel atrane-like six-coordinate (RO)(2)TaL complexes [where R = Me or Et and L = tris(2-oxy-3,5-dimethylbenzyl)amine] containing three six-membered rings have been synthesized and characterized. The R = Me complex is the first group 5 representative of this class of compounds structurally characterized by X-ray means. Somewhat surprisingly, these compounds failed to function as single-site initiators for the polymerization of l-LA to isotactic PLA and rac-LA to atactic PLA, whereas Ta(OEt)(5) and two titanium analogues ROTiL (where R = 2,6-di-i-PrC(6)H(3) and i-Pr) as well as Ti(O-i-Pr)(4) were effective catalysts for both polymerizations. 相似文献