14041-46-4Relevant articles and documents
Liquid-liquid solvent extraction of rare earths from chloride medium with sec-nonylphenoxy acetic acid and its mixtures with neutral organophosphorus extractants
Xiao, Pengfei,Bao, Changli,Song, Naizhong,Li, Cui,Jia, Qiong
, p. 1157 - 1161 (2011/10/18)
In the present study, sec-nonylphenoxy acetic acid (CA100) and its mixtures with four neutral organophosphorus extractants, tri-butyl-phosphate (TBP), 2-ethylhexyl phosphonic acid di-2-ethyl ester (DEHEHP), Cyanex923, and Cyanex925 have been applied to the extraction of rare earths. Results show that all the four mixing systems do not have evident synergistic effects on the extraction of rare earths. The different extraction effects have been considered to the separation of rare earths. The four mixtures may be applied to the separation of yttrium from some certain lanthanoids at proper mole fractions of CA100. Pleiades Publishing, Ltd., 2011.
Effect of the 18-crown-6 and benzo-18-crown-6 on the solvent extraction and separation of lanthanide(III) ions with 8-hydroxyquinoline
Atanassova
, p. 1304 - 1311 (2008/10/09)
The synergistic solvent extraction of 13 lanthanides with mixtures of 8-hydroxyquinoline (HQ) and the crown ethers (S) 18-crown-6 (18C6) or benzo-18-crown-6 (B18C6) in 1,2-dichloroethane has been studied. The composition of the extracted species has been
Temperature dependent rate constants for the reactions of gas phase lanthanides with N2O
Campbell, Mark L.
, p. 562 - 566 (2007/10/03)
The reactivity of gas phase lanthanide (Ln) atoms (Ln=La-Yb with the exception of Pm) with N2O from 298 to 623 K is reported. Lanthanide atoms were produced by the photodissociation of Ln(TMHD)3 (TMHD=2,2,6,6-tetramethyl-3,5-heptanat
Temperature-Dependent Rate Constants for the Reactions of Gas-Phase Lanthanides with O2
Campbell, Mark L.
, p. 7274 - 7279 (2007/10/03)
The reactivity of the gas-phase lanthanide atoms Ln (Ln = La-Yb with the exception of Pm) with O2 is reported. Lanthanide atoms were produced by the photodissociation of [Ln(TMHD)3] and detected by laser-induced fluorescence. For all the lanthanides studied with the exception of Yb, the reaction mechanism is bimolecular abstraction of an oxygen atom. The bimolecular rate constants (in molecule-1 cm3 s-1) are described in Arrhenius form by k[Ce(1G4)] = (3.0 ± 0.4) × 10-10 exp(-3.4 ± 1.3 kJ mol-1/RT); Pr(4I9/2), (3.1 ± 0.7) × 10-10 exp(-5.3 ± 1.5 kJ mol-1/RT); Nd(5I4), (3.6 ± 0.3) × 10-10 exp(-6.2 ± 0.4 kJ mol-1/RT); Sm(7F0), (2.4 ± 0.4) × 10-10 exp(-6.2 ± 1.5 kJ mol-1/RT); Eu(8S7/2), (1.7 ± 0.3) × 10-10 exp(-9.6 ± 0.7 kJ mol-1/RT); Gd(9D2), (2.7 ± 0.3) × 10-10 exp(-5.2 ± 0.8 kJ mol-1/RT); Tb(6H15/2), (3.5 ± 0.6) × 10-10 exp(-7.2 ± 0.8 kJ mol-1/RT); Dy(5I8), (2.8 ± 0.6) × 10-10 exp(-9.1 ± 0.9 kJ mol-1/RT); Ho(4I15/2), (2.4 ± 0.4) × 10-10 exp(-9.4 ± 0.8 kJ mol-1/RT); Er(3H6), (3.0 ± 0.8) × 10-10 exp(-10.6 ± 1.1 kJ mol-1/RT); Tm(2F7/2), (2.9 ± 0.2) × 10-10 exp(-11.1 ± 0.4 kJ mol-1/RT), where the uncertainties represent ±2σ. The reaction barriers are found to correlate to the energy required to promote an electron out of the 6s subshell. The reaction of Yb(1S0) with O2 reacts through a termolecular mechanism. The limiting low-pressure third-order rate constants are described in Arrhenius form by k0[Yb(1S0)] = (2.0 ± 1.3) × 10-28 exp(-9.5 ± 2.8 kJ mol-1/RT) molecule-2 cm6 s-1.
Thermodynamics of sublimation and crystal chemistry of Tm0.77Te
Petzel, T.,Ludwigs, J.,Greis, O.
, p. 317 - 328 (2008/10/08)
The congruent vaporization of solid Tm0.77Te (rhombohedral, with hexagonal lattice parameters a = 430.9 pm, c = 1083.8 pm) was investigated by the Knudsen effusion weight-loss technique over the temperature range 1624 - 1798 K. Using literature data for the enthalpies of dissociation of gaseous TmTe and Te2 and for the free energy functions of gaseous TmTe, Te2, thulium and tellurium, an equation for vaporization to the atoms is given. A vapor pressure equation is provided. Second and third law calculations based on estimated thermodynamic data for Tm0.77Te yielded the standard enthalpies and entropies of reaction. The crystal chemistry and thermochemical properties are discussed.
Acid Solvolysis Kinetics of Lanthanide Porphyrins
Haye, Shirleyanne,Hambright, Peter
, p. 666 - 668 (2007/10/02)
The kinetics of the acid solvolysis reactions of twelve water-soluble lanthanide tetrakis(N-methyl-4-pyridyl)porphyrins (Ln-P) follow rate = k1+>2/ (k-1/k2) + +>> at 25 deg C, I = 0.8M (LiNO3/HNO3) indicating that two protons are required for solvolysis, and since log (k1k2/k-1) = 45.0R0 - 39.4 (R0 is the ionic radius in Angstroem), a 0.1 Angstroem change in radius has a 32000 fold rate effect.
COMPLEX FORMATION VS. DISPROPORTIONATION: LANTHANIDE(II) CHLORIDES, MCl//2 (M EQUVLNT Nd, Sm, Eu, Dy, Tm, Yb), UNDER THE INFLUENCE OF ALKALI CHLORIDES.
Schleid, Thomas,Meyer, Gerd,Morss, Lester R.
, p. 187 - 193 (2008/10/08)
The products of the action of alkali metals (A EQUVLNT Li, Na) on lanthanide(III) chlorides, MCl//3 (M EQUVLNT Nd, Sm, Eu, Dy, Tm, Yb), principally ACl plus MCl//2 or LiCl plus LiM//2Cl//5, were reacted with CsCl in sealed tantalum containers. Complex formation (CsMcl//3) and disproportionation (to Cs//2AMCl//6 plus M) are the competing reaction types. The presence of alkali chloride (LiCl, NaCl) has no effect on complex formation of M EQUVLNT Eu, Yb, and only minimal effect for M EQUVLNT Sm. For M EQUVLNT Tm disproportionation is the principal and for M EQUVLNT Dy, Nd the exclusive process.
