AEuAsS3 (A = Li, K, Rb, and Cs): New As3+ species from an arsenic-rich polysulfide flux.

Four europium compounds, LiEuAsS 3 ( I), KEuAsS 3 ( IIa), RbEuAsS 3 ( IIb), and CsEuAsS 3 ( IIc), containing As (3+) were synthesized in molten alkali-metal polysulfide salts. An As-rich flux was found to be necessary to stabilize the pyramidal building unit [AsS 3] (3-). All crystallize in the monoclinic space group P2 1/ c with two new structure types.

Importance of solution equilibria in the directed assembly of metal chalcogenide mesostructures.

We describe the new nanostructured Pt/Ge/Se materials prepared from the molecular units [Ge2Se6](4-) and [GeSe4](4-) and linking Pt(2+) ions in the presence of surfactant micelles. X-ray diffraction coupled with transmission electron microscopy images reveals hexagonal pore symmetry. The solvent dependence and solution speciation of these building blocks were investigated by means of multinuclear NMR spectroscopy and by fast atom bombardment (FAB) mass spectroscopy and it is shown that rapid exchange equilibrium is reached between species like [Ge4Se10](4-), [Ge2Se6](4-), and [GeSe4](4-) in both water and formamide.

Layered metal sulfides: exceptionally selective agents for radioactive strontium removal.

In this article, we report the family of robust layered sulfides K(2x)Mn(x)Sn(3-x)S(6) (x = 0.5-0.95) (KMS-1).

[Zn(H2O)4][Zn2Sn3Se9(MeNH2)]: a robust open framework chalcogenide with a large nonlinear optical response.

[Zn(H2O)4][Zn2Sn3Se9(MeNH2)] has an open polar framework based on supertetrahedral clusters with a unique double connectivity mode and exhibits a strong second harmonic generation response, excellent acid stability and proton exchange capacity.

RE(AuAl2)nAl2(AuxSi1-x)2: a new homologous series of quaternary intermetallics grown from aluminum flux.

The combination of early rare earth metals (La- to Gd and Yb), gold, and silicon in molten aluminum results in the formation of intermetallic compounds with four related structures, forming a new homologous series: RE[AuAl2]nAl2(AuxSi(1-x))2, with x approximately 0.5 for most of the compound and n = 0, 1, 2, and 3. Because of the highly reducing nature of the Al flux, rare earth oxides instead of metals can also be used in these reactions.

Improved resolution and detection of 31P-Tl J-couplings at 21 T in 31P magic angle spinning NMR spectra of inorganic compounds containing Tl/Bi/P/S.

For crystalline compounds containing Tl, Bi, P, and S, greatly improved chemical shift resolution was observed in 31P magic angle spinning spectra obtained at 21 T relative to spectra obtained at 9.4 T. In Hz units, the spectral linewidths were not strongly dependent on the applied field, which may be a result of a significant contribution to the linewidths from transverse relaxation.

Low valent phosphorus in the molecular anions [P5Se12]5- and beta-[P6Se12]4-: phase change behavior and near infrared second harmonic generation.

The caesium salts of the novel molecular anions [P5Se12]5- and [P6Se12]4- are phase change materials and exhibit near infrared, non-linear optical second harmonic generation; [P5Se12]5- is a coordination complex with an octahedral P3+ center chelated by two [P2Se6]4- ligands whereas [P6Se12]4- features a [P2]4+ dimer chelated by two [P2Se6]4- ligands.

New potassium bismuth thiophosphates including the modulated K(1.5)Bi(2.5)(PS4)(3).

The compounds K3Bi3(PS4)4 (I), K1.5Bi2.5(PS4)3 (II), and K9Bi(PS4)4 (III) were synthesized, and their properties are described.

Atomic ordering and gap formation in Ag-Sb-based ternary chalcogenides.

Novel semiconductors with tailored properties can be designed theoretically based on our understanding of the interplay of atomic and electronic structures and the nature of the electronic states near the band-gap region. We discuss here the realization of this idea in Ag-Sb-based ternary chalcogenides, which are important optical phase change and thermoelectric materials. Based on our studies we propose new systems for high-performance thermoelectrics.

Helical polymer 1/infinity[P2Se6(2-)]: strong second harmonic generation response and phase-change properties of its K and Rb salts.

The selenophosphates A2P2Se6 (A = K, Rb) crystallize in the chiral trigonal space group P3121, with a = 7.2728(9) A, c = 18.872(4) A, and Z = 3 at 298(2) K and a = 14.

Eu3(AsS4)2 and AxEu(3-y)As(5-z)S10 (A = Li, Na): compounds with simple and complex thioarsenate building blocks.

Eu(3)(AsS(4))(2) and A(x)Eu(3-y)As(5-z)S(10) (A = Li, Na) are the members of a new thioarsenate family. They feature As(5+) and As(3+) centers, respectively. The rhombohedral Eu(3)(AsS(4))(2) features a new structure type consisting of eight-coordinate Eu(2+) centers and AsS(4)(3-) anions, whereas the monoclinic A(x)Eu(3-y)As(5-z)S(10) (Li(0.

Porous semiconducting gels and aerogels from chalcogenide clusters.

Inorganic porous materials are being developed for use as molecular sieves, ion exchangers, and catalysts, but most are oxides. We show that various sulfide and selenide clusters, when bound to metal ions, yield gels having porous frameworks. These gels are transformed to aerogels after supercritical drying with carbon dioxide.

REAu2In4 (RE = La, Ce, Pr, Nd): polyindides from liquid indium.

The series of compounds REAu2In4 (RE = La, Ce, Pr, Nd) crystallize from excess In as rod-shaped single crystals. All members adopt the orthorhombic space group Pnma with a = 18.506(2) A, b = 4.

Spinodal decomposition and nucleation and growth as a means to bulk nanostructured thermoelectrics: enhanced performance in Pb(1-x)Sn(x)Te-PbS.

The solid-state transformation phenomena of spinodal decomposition and nucleation and growth are presented as tools to create nanostructured thermoelectric materials with very low thermal conductivity and greatly enhanced figure of merit. The systems (PbTe)(1-x)(PbS)(x) and (Pb(0.95)Sn(0.

Wide compositional and structural diversity in the system Tl/Bi/P/Q (Q=S, Se) and observation of vicinal P-Tl J coupling in the solid state.

The compounds alpha-TlBiP2Se6 (I), beta-TlBiP2Se6 (II), TlBiP2S6 (III), Tl3Bi3(PS4)4 (IV), TlBiP2S7 (V), and Tl3Bi(PS4)2 (VI) were synthesized, and the structures of I-V were determined by single-crystal X-ray diffraction analysis. The structure of I features infinite chains. Those of compounds II, III, and V are layered.

Heavy-metal-ion capture, ion-exchange, and exceptional acid stability of the open-framework chalcogenide (NH(4))(4)In(12)Se(20).

The hydrothermal synthesis of the purely inorganic open-framework indium selenide (NH(4))(4)In(12)Se(20) (1) is reported. Compound 1 exhibits a unique three-dimensional open-framework structure. The framework of 1 shows an unusual, for a chalcogenide compound, rigidity arising from the unprecedented connection mode of its building blocks.

Nanostructures versus solid solutions: low lattice thermal conductivity and enhanced thermoelectric figure of merit in Pb9.6Sb0.2Te10-xSex bulk materials.

The series of Pb(9.6)Sb(0.2)Te(10)(-)(x)Se(x) compounds with different Se content (x) were prepared, and their structure was investigated at the atomic and nanosized regime level.

Divergence in the behavior of the charge density wave in RETe3 (RE = rare-earth element) with temperature and RE element.

Comparable changes in the volume of RETe3 materials caused by temperature and RE size have opposite trends to the incommensurate charge density wave modulation. This is unique behavior among all reported charge density wave materials.

Indium flux synthesis of RE4Ni2InGe4 (RE = Dy, Ho, Er, and Tm): an ordered quaternary variation on the binary phase Mg5Si6.

The quaternary compounds RE4Ni2InGe4 (RE = Dy, Ho, Er, and Tm) were obtained as large single crystals in high yields from reactions run in liquid In. The title compounds crystallize in the monoclinic C2/m space group with the Mg(5)Si(6) structure type with lattice parameters a = 15.420(2) A, b = 4.

Hexagonal mesoporous germanium.

The blending of mesoporosity with the properties of semiconductors promises new types of multifunctional nanomaterials. It would be particularly interesting to combine the shape selectivity of a mesoporous oxide with the electronic and photonic characteristics of a useful semiconductor. We demonstrated the synthesis of a mesoporous germanium semiconductor using liquid-crystals-templated chemistry.

Unique pore selectivity for Cs+ and exceptionally high NH4+ exchange capacity of the chalcogenide material K6Sn[Zn4Sn4S17].

Highly selective ion-exchange properties and -exchange capacities of the open framework chalcogenide material K(6)Sn[Zn(4)Sn(4)S(17)] (1) with Cs(+) and NH(4)(+) are reported. Because the structure of this framework is known in great detail, these studies are a rare example where structure/property relationships can be directly drawn. 1 possesses three types of micropore cavities.