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The novel NDOE (1,12,15-triaza-3,4:9,10-dibenzo-5,8-dioxacycloheptadecane) ion exchange resin was prepared. The ion exchange capacity of NDOE azacrown ion exchanger was 02 meq/g dry resin. A study on the separation of lithium isotopes was carried out with NDOE novel azacrown ion exchange resin. The lighter isotope, 6Li concentrated in the solution phase, while the heavier isotope, 7Li is enriched in the resin phase. By column chromatography (0.1 cm I.D.• cm height) using 2.0M NH4C1 as an eluent, a separation factor, a = 1.0201 was obtained.

3) In 0.13 were synthesized using a conventional high temperature synthetic method as we attempted to introduce the p-type double-doping of Li and In for RE and Ge in the RE 5-x Li x Ge 4-y (RE = rare-earth metals) system, and their crystal structures were characterized by single crystal X-ray diffraction experiments. The two title compounds crystallize in the orthorhombic space group Pnma (Pearson code oP16, Z = 4) with six crystallographically independent asymmetric atomic sites and adopt the Gd 5 Si 4 -type structure. Overall crystal structures of two isotypic title compounds can be described as a 1:1 assembly of the hypothetical 2-dimensional (2D) RE 2 (RE/Li)(In/Ge) 2 layered structure adopting the Mo 2 FeB 2 -type structure and the dumbbell-shaped inter-slab (In/Ge) 2 dimers bridging two such neighboring 2D layers along the crystallographic b-axis direction. The observed "direction selective" structural transformation from the Sm 5 Ge 4 -type to the Gd 5 Si 4 -type structure can be understood as a result of the simultaneous double-doping by the relatively smaller amount of Li substitution for La at the RE3 site than that in the La 4 LiGe 4 and the partial In substitution for Ge at both of the M1 and M3 sites. The site-preference of In for two particular anionic sites were thoroughly studied using four hypothetical La 4 LiGe 3 In models having different atomic arrangements by the tight-binding linear muffin-tin orbital (TB-LMTO) method. The overall electronic structure and individual chemical bonding influenced by the given double-doping were also discussed on the basis of the density of states (DOS) and crystal orbital Hamilton population (COHP) curves analyses.

System. -The title compounds are synthesized from the elements (Nb tube, 1075°C, 5 h, followed by annealing at 750°C for 2 d). The products are characterized by powder and single crystal XRD, magnetic measurements, and TB-LMTO electronic structure calculations. They crystallize in the orthorhombic space group Pnma with Z = 4 (Gd5Si4-type structure). The structure contains two-dimensional Ln2LiGe2 slabs (Ln: La, Ce, Pr, and Sm) and Ge2 dimers bridging two neighboring slabs. Li substitution for rare-earth elements in the title system leads to a combined effect of increasing chemical pressure and decreasing valence electron concentration, which results in the structure transformation from the binary parental Sm 5 Ge 4 -type structure to the Gd 5 Si 4 -type structure. The non-magnetic Li substitution leads to a ferromagnetic-like ground state for Ce 4 LiGe 4 and the coexistence of antiferromagnetic and ferromagnetic ground states for Sm4LiGe4. -(NAM, G.; JEON, J.; KIM, Y.; KANG, S. K.; AHN, K.; YOU*, T.-S.; J. Solid State Chem. 205 (2013) 10-20, http://dx.

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Four polar intermetallic compounds belonging to the RE2In1−xLixGe2 (RE = La, Nd, Sm, Gd; x = 0.13(1), 0.28(1), 0.43(1), 0.53(1)) system have been synthesized by the traditional solid-state reaction method, and their crystal structures have been characterized by single-crystal X-ray diffraction (SXRD) analyses. The isotypic crystal structures of four title compounds adopt the Mo2FeB2-type structure having the tetragonal space group P4/mbm (Z = 2, Pearson code tP40) with three crystallographically independent atomic sites and can be simply described as a pile of the identical 2-dimensioanl (2D) RE2In1-xLixGe2 slabs stacked along the c-axis direction. The substituting Li atom shows a particular site preference for replacing In at the Wyckoff 2a site rather than Ge at the Wyckoff 4g in this crystal structure. As the size of a used rare-earth metal decreases from La3+ to Gd3+ throughout the title system, the Ge-Ge and Ge-In/Li bond distances, both of which consist of the 2D anionic Ge2(In/Li) layer, gradually decrease resulting in the reduction of a unit cell volume. A series of theoretical investigations has been performed using a hypothetical structure model Gd2In0.5Li0.5Ge2 by tight-binding linear muffin-tin orbital (TB-LMTO) method. The resultant densities of states (DOS) value at the Fermi level (EF) suggests a metallic conductivity for this particular composition, and this calculation result is in a good agreement with the formal charge distribution assigning two extra valence electrons for a metal-metal bond in the conduction band. The thorough analyses of six crystal orbital Hamilton population (COHP) curves representing various interatomic interactions and an electron localization function (ELF) diagram indicating the locations of paired-electron densities are also provided in this article.

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