[en] In this study, the silicone thermal curing degree of the silicone-encapsulated quantum dot light emission diode was measured using the various types of chemical ligands around quantum dot. It was confirmed that the trioctyl phosphin oxide (TOPO) ligand around the quantum dot was responsible for dispersion of the quantum dot in silicone encapsulant and decline of the thermal curing degree of the silicone encapsulant. Also, it was confirmed that the thermal curing degree of silicone encapsulants containing the steric acid (SA) and the dodecanoic acid (DA) ligands were higher than the one of TOPO ligand

[en] The synergic extraction of rare earth(III) ions (RE; La, Sm, Tb and Lu) using 2-thenoyltrifluoroacetone (Htta) and phosphoryl-type uncharged bidentate ligands, such as tetraphenyldiphosphine dioxide (tpdpo) or bis(diphenylphosphinyl)methane (bdppm), was investigated in benzene. The synergic enhancement was attributed to the formation of the adduct RE(tta)₃S_n (n=1 or 2 for tpdpo and n=1 for bdppm) in benzene, where S denotes the uncharged ligand. The adduct formation constants (β_S) and the synergic extraction constants were determined. For each RE(III), the β_S,1 value for bdppm is larger than the β_S,1 and β_S,2 values for tpdpo and the β_S values for both ligands decrease with increasing atomic number of RE(III)

[en] Liquid chromatography with a free stationary phase (LCFSP, countercurrent chromatography) can be used to separate Am(III) and Eu(III) in systems with neutral bidentate organophosphorus extractants. If CHCl₃ solutions of tetraphenylmethylenediphosphine dioxide (TPMDPD) are used as the stationary phase, Eu(III) is first eluted by 0.5 M NH₄SCN-1 M HCl and then Am(III) by 0.025 M hydroxyethylidenediphosphonic acid (HEDPA) in water. If CHCl₃ solutions of 1,2,4-tris(diphenylphosphinylmethyl)benzene (1,2,4-TDPPMB) are used as the stationary phase, the elements are separated by elution with 3 M HNO₃ with Am eluting first. In both instances, 3-5 ml fractions contain 96-99% of one of the elements and no impurity of the other. 14 refs., 5 figs

[en] A series of organotin complexes was prepared involving phosphines bonded to the organotin moiety. The series include derivatives of SnCl_xPh_4-x (where x varied from zero to four with the phosphines Ph₃P, (Ph₂P)CH₂, (Ph₂P)₂(CH₂)₂, cis-(Ph₂P)CH₂, and CH₃C(CH₂PPh₂)₃. A host of new complexes was obtained, showing different stoichiometries, bonding modes, and coordination numbers around the tin atom. These complexes were characterized by several different chemical and physical methods. The ¹¹⁹Sn Moessbauer parameters varied differently. Whereas isomer shift values did not great variation for each group of complexs with the same organotin parent (SnCl_xPh_4-x), reflecting a small change in s charge distribution on the Sn atom upon complexation, quadrupole splitting results varied widely, however, when the parent organotin compound was wholly symmetric (SnCl₄ and SnPPh₄), the complexes also tended to show quadrupole splitting values approaching zero. (author)

[en] This paper is a review of the history, synthesis and application of organophosphorus compounds, especially of those of pentavalent phosphorus, such as phosphoramidates, phosphorothioates, phosphonates and phosphonic acids with insecticide and anticancer activities. The organophosphorus compounds with agrochemical applications show great structural variety, They include not only insecticides, but also fungicides, herbicides, and others. The large variety of commercially available organophosphorus pesticides is remarkable. Even more interesting is the high efficiency of some organophosphorus compounds as anticancer agents such as cyclophosphamide and its derivatives. (author)

[en] This is an exhaustive review of phosphorus-functionalized calix arenes. Effective methodologies are describes that allow preparation of derivatives with phosphate, phosphine oxide and P(III)-containing groups. It is shown that phosphoryl-containing calix arenes display interesting ionophoric properties, in particular with respect to the extraction and separation of lanthanides and actinides. (authors)

[en] The rare earth elements, compounds and complexes have evoked a great deal of interest because of their peculiar structure, properties and industrial and biochemical importance. In the present paper, we present the analysis of various XANES features of the L-absorption edges of Dy complexes with ligands of biological importance (viz. acetylacetone (acac), ethylacetoacetate (eaa), triphenyl phosphine oxide thiocyanate (tppo)(NCS), dipyridyl nitrate (dipy)(NO₃), triphenyl phosphine oxide nitrate (tppo)(NO₃), etc.) Such a study is helpful in understanding the behaviour of the Dy(III) ion and its biological applications. ((orig.))

No abstract available

[en] Splitting due to tunnelling via the potential energy barrier has played a significant role in the study of molecular spectra since the early days of spectroscopy. The observation of the ammonia doublet led to attempts to find a phosphine analogous, but these have so far failed due to its considerably higher barrier. Full dimensional, variational nuclear motion calculations are used to predict splittings as a function of excitation energy. Simulated spectra suggest that such splittings should be observable in the near infrared via overtones of the ν₂ bending mode starting with 4ν₂.

[en] Nuclear process solutions typically contain significant quantities of radionuclides and some transition metal elements. These wastes generated at nuclear facilities generally contain mixtures of long-lived and short-lived radioactive elements. The Nuclear Regulator Commission requires that the long-lived α-emitting elements be removed from the waste solutions and safely isolated from the environment. In addition, some components of the radioactive open-quotes wasteclose quotes solutions can be recycled. It is now important that efficient separation schemes is developed to selectively isolate radioactive isotopes. The focus of this work has been to develop ligands that will selectively extract various radio nuclides from waste water streams based on size and electronic properties of the metal ion. It was previously found that the lanthanides and actinides form complexes of the general type, M(NO₃)₃(L)₃ with mono-dentate chelators. It was rationalized that if three mono-dentate chelators would attach to one metal atom, then perhaps one tripodal molecule of the general form HC[(CH₂)_nP(O)R₂]₃, with three chelating sites could be used to trap a metal ion. With all of the ligands attached to one molecule, the bite size could then be controlled to add selectivity based on metal ion size. The R-groups attached to the ligand might also be altered to allow for differentiation among ions that are similar in size but different in oxidation state. During the course of this work, a scheme for synthesis of HC(CH₂CH₂Cl)₃, the basic starting material, was developed and was used in the synthesis of HC(CH₂CH₂PPh₂)₃, HC(CH₂CH₂PEt₂)₃, HC[CH₂CH₂P(t-Bu)₂]₃, HC[CH₂CH₂P(n-Bu)₂]₃ and HC(CH₂CH₂CH₂P-Ph₂)₃ with the corresponding oxides and sulfides