Using the method to synthesize rare-earth metal(III) fluoride sulfides MFS (M=Y, La, Ce-Lu), in some cases we were able to obtain mixed-valent compounds Such as Yb3F4S2 instead. With Eu3F4S2 another isotypic representative has now been synthesized. Eu3F4S2 (tetragonal, 14/mmm, a=400.34(2), c=1928.17(9)pm, Z=2) is obtained from the reaction of metallic europium,, elemental sulfur, and europium trifluoride in a molar ratio of 5:6:4 within seven days at 850 degrees C in silica-jacketed gas-tightly sealed platinum ampoules. The single-phase product consists of black plate-shaped single crystals with a square Cross section, which can be obtained from a flux using equimolar amounts of NaCl as fluxing agent. The crystal structure is best described as an intergrowth structure, in which one layer of CaF2-type EuF2 is followed by two layers of PbFCl-type EuFS when sheeted parallel to the (001) plane. Accordingly there are two chemically and crystallographically different europium cations present. One of them (Eu2+) is coordinated by eight fluoride anions in a cubic fashion, the other one (Eu3+) exhibits a monocapped square antiprismatic coordination sphere with four F- and five S2- anions. Although the structural ordering of the different charged europium cations is plausible, a certain amount of charge delocalization with some polaron activity has to take place, which is Suggested by the black color of the title compound. Temperature dependent magnetic susceptibility measurements of Eu3F4S2 show Curie-Weiss behavior with an experimental magnetic moment of 8.19(5) mu(B) per formula unit and a paramagnetic Curie temperature of 0.3(2) K. No magnetic ordering is observed down to 4.2 K. In accordance with an ionic formula splitting like (Eu-II)(Eu-III)(2)F4S2 only one third of the europium centers in Eu3F4S2 carry permanent magnetic moments. Eu-151-Mossbauer spectroscopic experiments at 4.2 K show one signal at an isomer shift of - 12.4(1) mm/s and a second one at 0.42(4) mm/s. These signals occur in a ratio of 1 :2 and Correspond to Eu2+ and Eu3+, respectively. The spectra at 78 and 298 K are similar, thus no change in the Eu2+/Eu3+ fraction can be detected. (C) 2009 Elsevier Inc. All Fights reserved.

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EuPdGe was prepared from the elements by reaction in a sealed tantalum tube in a high-frequency furnace. Magnetic susceptibility measurements show Curie–Weiss behavior above 60K with an experimental magnetic moment of 8.0(1)μB/Eu indicating divalent europium. At low external fields antiferromagnetic ordering is observed at TN=8.5(5)K. Magnetization measurements indicate a metamagnetic transition at a critical field of 1.5(2)T and a saturation magnetization of 6.4(1)μB/Eu at 5K and 5.5T. EuPdGe is a metallic conductor with a room-temperature value of 5000±500μΩcm for the specific resistivity. 151Eu Mössbauer spectroscopic experiments show a single europium site with an isomer shift of δ=−9.7(1)mm/s at 78K. At 4.2K full magnetic hyperfine field splitting with a hyperfine field of B=20.7(5)T is observed. Density functional calculations show the similarity of the electronic structures of EuPdGe and EuPtGe. T–Ge interactions (T=Pd, Pt) exist in both compounds. An ionic formula splitting Eu2+T0Ge2− seems more appropriate than Eu2+T2+Ge4− accounting for the bonding in both compounds. Geometry optimizations of EuTGe (T=Ni, Pt, Pd) show weak energy differences between the two structural types.

The new layered oxonitridosilicate EuSi(2)O(2)N(2) has been synthesized in a radio-frequency furnace at temperatures of about 1400 degrees C starting from europium(III) oxide (Eu(2)O(3)) and silicon diimide (Si(NH)(2)). The structure of the yellow material has been determined by single-crystal X-ray diffraction analysis (space group P1 (no. 1), a=709.5(1), b=724.6(1), c=725.6(1) pm, alpha=88.69(2), beta=84.77(2), gamma=75.84(2) degrees ,V=360.19(9)x10(6) pm(3), Z=4, R1=0.0631, 4551 independent reflections, 175 parameters). Its anionic Si(2)O(2)N(2) (2-) layers consist of corner-sharing SiON(3) tetrahedra with threefold connecting nitrogen and terminal oxygen atoms. High-resolution transmission electron micrographs indicate both ordered and disordered crystallites as well as twinning. Magnetic susceptibility measurements of EuSi(2)O(2)N(2) exhibit Curie-Weiss behavior above 20 K with an effective magnetic moment of 7.80(5) mu(B) Eu(-1), indicating divalent europium. Antiferromagnetic ordering is detected at 4.5(2) K. EuSi(2)O(2)N(2) shows a field-induced transition with a critical field of 0.50(5) T. The four crystallographically different europium sites cannot be distinguished by (151)Eu Mössbauer spectroscopy. The room-temperature spectrum is fitted by one signal at an isomer shift of delta=-12.3(1) mm s(-1) subject to quadrupole splitting of DeltaE(Q)=-2.3(1) mm s(-1) and an asymmetry parameter of 0.46(3). Luminescence measurements show a narrow emission band with regard to the four crystallographic europium sites with an emission maximum at lambda=575 nm.

[C6H21N4][Sb9S14O] represents the first known oxo-thioantimonate with an organic ion acting as structure director. The compound 3 crystallizes in the non-centrosymmetric space group Cmc2(1) with a = 29.679(2), b = 9.9798(6), c = 11.7155(7) angstrom, V = 3470.1(4) angstrom(3) Z = 4. The structure contains the hitherto unknown [SbS2O] unit as a structural motif. The [SbS3] trigonal pyramids and [SbS2O] units are joined to form a 10-membered ring with large pores having a diameter of 7.7 angstrom x 8.3 angstrom. The organic template molecule acts like a tetra-dentate ligand around the O atom of the [SbS2O] group. Depending on the value chosen for the Sb-S bond lengths, the material contains a 1-, 2- or 3-dimensional anion. The optical band gap of 2.03 eV demonstrates that the material is an optical semi-conductor. Upon heating, the compound decomposes in two steps yielding finally a mixture of Sb and Sb2S3. The Sb-121 Mossbauer spectrum shows a relative large line width in accordance with the superposition of the five signals. (c) 2006 Elsevier Inc. All rights reserved.

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The new stannide Li(2)AuSn(2) was prepared by reaction of the elements in a sealed tantalum tube in a resistance furnace at 970 K followed by annealing at 720 K for five days. Li(2)AuSn(2) was investigated by X-ray diffraction on powders and single crystals and the structure was refined from single-crystal data: Z=4, I4(1)/amd, a=455.60(7), c=1957.4(4) pm, wR2=0.0681, 278 F(2) values, 10 parameters. The gold atoms display a slightly distorted tetrahedral tin coordination with Au-Sn distances of 273 pm. These tetrahedra are condensed through common corners leading to the formation of two-dimensional AuSn(4/2) layers. The latter are connected in the third dimension through Sn-Sn bonds (296 pm). The lithium atoms fill distorted hexagonal channels formed by the three-dimensional [AuSn(2)] network. Modestly small (7)Li Knight shifts are measured by solid-state NMR spectroscopy that are consistent with a nearly complete state of lithium ionization. The noncubic local symmetry at the tin site is reflected by a nuclear electric quadrupolar splitting in the (119)Sn Mössbauer spectra and a small chemical shift anisotropy evident from (119)Sn solid-state NMR spectroscopy. Variable-temperature static (7)Li solid-state NMR spectra reveal motional narrowing effects at temperatures above 200 K, revealing lithium atomic mobility on the kHz time scale. Detailed lineshape as well as temperature-dependent spin lattice relaxation time measurements indicate an activation energy of lithium motion of 27 kJ mol(-1).

The structural organization of Sb2O3-SbPO4 glasses has been studied by FTIR, Raman, P-31 MAS and spin echo NMR, Mossbauer and X-ray absorption spectroscopy (EXAFS and XANES at K and L-3,L-1-Sb edges). The combined results can be explained in terms of two potential mechanisms describing the change of the Sb(m) local environment upon incorporation of Q((4))-type phosphate. The formation of the latter species requires anionic compensation that may be adjusted by (a) formation of non bridging oxygen or (b) formation of SbO4E- groups (E = non-bonding electron pair). The second model is favored.

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The isotypic nitridosilicates MYb[Si4N7] (M = Sr, Ba, Eu) were obtained by the reaction of the respective metals with Si(NH)(2) in a radiofrequency furnace below 1600 degreesC. On the basis of powder diffraction data of MYb[Si4N7] Rietveld refinements of the lattice constants were performed; these confirmed the previously published single-crystal data. The compounds contain a condensed network of corner-sharing [N(SiN3)(4)] units. The central nitrogen thus exhibits ammonium character. Magnetic susceptibility measurements of MYb[Si4N7] (M = Sr, Ba, Eu) show paramagnetic behavior with experimental magnetic moments of 3.03(2), (Sr), 2.73(2) (Ba), and 9.17(2) (Eu) mu(B) per formula unit. In EuYb-Si4N7 the europium and ytterbium atoms are in stable divalent and trivalent states, respectively. According to the non-magnetic character of the alkaline earth cations, ytterbium has to be in an intermediate valence state YbIII-x in the strontium and barium compound. Consequently, either a partial exchange N3-/O2- resulting in compositions MYbIII-x[(Si4N7xOx)-O-_] or an introduction of anion defects according to MYbIII-x[Si4N7-x/(3)square(x/3)] has to be assumed. The phase width 0 less than or equal to x less than or equal to 0.4 was estimated according to the magnetic measurements. Eu-151 Mossbauer spectra of EuYb[Si4N7] at 78 K show a single signal at an isomer shift of delta = -12.83(3) mm s(-1) subject to quadrupole splitting of DeltaE(Q) = 5.7(8) mm s(-1), compatible with purely divalent europium.

The model glasses NBS1 and NBS2 are sodium borosilicate glasses of high intrinsic UV transmission. Although both glasses have an SiO2 content of 74 mol%, they possess different matrix structures due to varied Na2O/B2O3 ratios. Nonbridging oxygens occur in the NBS1 but not in the NBS2 glass.Fe, Ti and Sb oxides were added at concentrations of 1 and 10 mol% to study valence, coordination and site distribution. XANES, Mossbauer, optical absorption, photoluminescence and EPR spectroscopy provided an insight into the structures and near range environments of the dopants.Large differences were found for the two Fe doped glasses. The presence of nonbridging oxygens in NBS1 glass leads to a higher solubility of the Fe ions and a higher ratio of tetrahedral over octahedral Fe3+ coordination while a clustering of Fe ions resulting in a lowered UV and VIS transmission is observed in NBS2 glass. In Ti doped glasses EPR and XANES spectroscopy shows that most Ti occurs as Ti4+, in four-, five- and sixfold coordination. Optical spectra of Ti4+ display high intensity charge transfer transitions in the UV region. Ti4+ photoluminescence in the visible range is of low intensity.Optical absorption, XANES and Mossbauer spectroscopy could only detect Sb3+ in the antimony doped glasses. The photoluminescence of Sb3+ is much stronger in the NBS1 than in the NBS2 glass.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Eu-3[BN2](2) and LiEu4[BN2](3) were synthesized from a stoichiometric mixture of EuN, BN, europium metal and Li3N, EuN and BN (ratio: 1:4:3) in sealed niobium ampoules at 1475 and 1275 K, respectively. Temperature dependent susceptibility measurements of Eu-3[BN2](2) and LiEu4[BN2](3) show Curie-Weiss behavior with experimental magnetic moments of 8.03(5) and 8.5(1) mu(B)/Eu atom, respectively, compatible with divalent europium. Both nitridoborates order ferromagnetically at T-C = 32.0(5) K (Eu-3[BN2](2)) and 22.0(5) K (LiEu4[BN2](3)). The saturation magnetizations of 5.73(5) mu(B)/Eu atom at 5 K and 7 T for Eu-3[BN2](2) and 4.2 mu(B)/Eu atom at 5 K and 2 T for LiEu4(BN2)(3) are smaller than the maximum value of 7 mu(B). Eu-151 Mossbauer data of Eu-3[BN2](2) at 4.2 K show an isomer shift of -11.4(1) mm/s and an experimental line width of 3.1(2) mm/s. Full magnetic hyperfine field splitting with 26.2(3) T at the europium nuclei is detected. Vibrational spectra of Eu-3[BN2](2) are interpreted on the basis of discrete [BN2](3-) units with symmetry D-infinityh by taking into account the existence of two crystallographically independent [BN2](3-) anions and their dynamic coupling in the unit cell (factor group splitting).

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Pure samples of the ternary stannides LiTSn4 (T = Ru, Rh, Ir) have been synthesized from the elements in sealed tantalum tubes. They crystallize with an ordered version of the PdGa5 type. LiTSn4 (T = Ru, Rh, It) are all metallic conductors and Pauli paramagnets. Spectroscopic measurements indicate significant differences in the chemical bonding properties: As revealed by both Sn-119 Mossbauer spectroscopy and solid-state NMR data, the local electron distribution at the tin site is more anisotropic in LiRuSn4 compared to the other two materials. In addition, Li-7 Knight shift and spin-lattice relaxation times indicate that LiRuSn4 has a much higher electron density at the lithium atom arising from conduction electrons at the Fermi level. These findings are in good agreement with the results of DFT band structure calculations.

Eu2SnS4, Sr2SnS4, and Sr2GeSe4 have been synthesized by heating the elements or binary precursors at 1073 K and their crystal structures were determined by single crystal methods. Eu2SnS4 crystallizes with a new structure type (Pnma, a = 11.187(2), b = 8.768(2), c = 7.538(2) Angstrom, Z = 4), consisting of distorted [SnS4](4-) tetrahedra and sevenfold coordinated Eu2+ ions. Sr2SnS4 and gamma-Sr2GeSe4 are isostructural and form a new structure type likewise (Ama2, Z = 4, Sr2SnS4: a = 9.977(1), b = 10.311(2), c = 7.243(1) Angstrom, Sr2GeSe4: a = 10.284(2),b = 10.543(2), c = 7.41 (1) Angstrom) with more regular tetrahedral anions and strontium coordinated by seven and eight chalcogen atoms, respectively. Eu2SnS4 is a Curie-Weiss paramagnet (7.80(2) mu(B)/Eu; theta = 4.2(2) K) and orders antiferromagnetically at T-N = 5.5(2) K with a magnetization of 6.56(5) PB/Eu at 5.5 1 The divalent nature of europium is also evident from Eu-151 Mossbauer spectra which show a single signal at an isomer shift of - 12.2(l) mm/s at 78 K. Full magnetic hyperfine field splitting (19.5(2) T at the europium nuclei) is observed at 4.2 K. The Sn-119 spectrum shows one signal at 1.25(9) mm/s subject to quadrupole splitting of 0.76(2) mm/s. At 4.2 K a transferred hyperfine field of 3(1) T is detected at the tin site.

The stannide LiAuSn was synthesized by reaction of the elements in a sealed tantalum tube. Magnetic susceptibility measurements reveal Pauli paramagnetism. LiAuSn shows a single 119Sn Mössbauer signal at an isomer shift of 2.12(3) mm/s subject to a quadrupole splitting of 1.51(2) mm/s. The 119Sn MAS NMR spectrum reveals a strong Knight shift of 5183 ppm, The unique lithium site present in the crystal structure is reflected by a single 7Li NMR signal at 9.8 ppm. While a significant shift of this resonance towards larger frequencies at higher temperature indicates that the s-spin density at the lithium sites increases with increasing temperatures, no motional narrowing occurs up to 470 K. This result indicates that the lithium ions are immobile on the NMR timescale within the temperature range observed.

The tetrasubstituted polyanions of platinum, palladium, and gold [M(SnB(11)H(11))(4)](x-) (x=6, M=Pd, Pt; x=5, M=Au) have been prepared and characterized by single-crystal X-ray diffraction, elemental analysis, IR, Raman, (11)B, and (119)Sn heteronuclear NMR spectroscopy. In the case of the platinum derivative [Bu(3)MeN](6)[Pt(SnB(11)H(11))(4)] (2) (119)Sn Mössbauer spectroscopy has been carried out. The isolated salts are stable towards moisture and air and the complexes 2 and 3 were treated with 1,3-bis(diphenylphosphino)propane (dppp) to give the respective substitution products [Bu(3)MeN](2)[(dppp)M(SnB(11)H(11))(2)] (M=Pd, Pt).