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In contrast to the solid solution series (LiSbTe2)1-x(GeTe)x, compounds with compositions (NaSbTe2)1-x(GeTe)x are not thermodynamically stable at room temperature, but can be obtained as metastable phases by quenching melts with x ≤ 0.5. For x > 0.5 and in slowly cooled melts, samples are inhomogeneous. Despite the metastability, the lattice parameters of (NaSbTe2)1-x(GeTe)x show a Vegard-like behavior. The limited tendency toward forming solid solutions is due to the fact that the ionic radius of Na+ is much larger than that of Ge2+ or Li+ and thus the lattice parameter of NaSbTe2 (a = 6.32 A) being significantly larger than that of LiSbTe2 (a = 6.11 A). Measurements of transport properties revealed an increasing Seebeck coefficient with increasing GeTe content. Electrical and thermal conductivities of all members of the series (NaSbTe2)1-x(GeTe)x with x ≤ 0.5 are low with ∼15 mS cm−1 and 0.5 W m−1 K−1, respectively, which is consistent with the inherently low electrical conductivity of NaSbTe2. Nevertheless, this model system explains both the low thermoelectric performance of other chalcogenides with high Na contents and the widely recognized potential of Na as doping agent in thermoelectric materials.

Pt(II) and Cu(II) complexes, trans-[PtCl2(7AI3CAH)2] and [CuBr2(7AI3CAH)2]n, containing 7-azaindole-3-carboxaldehyde (7AI3CAH) have been synthesized and investigated by a single crystal X-ray diffraction, vibrational spectroscopy and DFT calculations. In the platinum(II) complex two pyridine nitrogen atoms of the 7AI3CAH ligands and two chloride ligands are coordinated to the central metal atom, in a square-planar trans arrangement. In the polymeric copper(II) complex the coordination geometry is a tetragonal bipyramid (4 + 2), where the in-plane ligands are two pyridine nitrogen atoms of two organic ligands and two trans-bromide ligands. The apical positions of bipyramid are occupied by the two Br ligands from the neighboring units. Thus, the CuBrBrCu double bridge system is formed. Detailed vibrational assignments of the IR and Raman spectra of the Pt(II) and Cu(II) complexes have been made on the basis of the calculated potential energy distributions (PEDs) using B3LYP method. The in vitro antiproliferative activity of trans-[PtCl2(7AI3CAH)2] was studied against different human cancer cell lines. The results have shown that this complex is comparably cytotoxic with cisplatin at the LoVo (colon cancer) and MCF7 (breast cancer) cells, whilst its cytotoxicity is significantly lower against the A549 cells (lung cancer) as compared to cisplatin. However, it is about 8-fold less toxic than cisplatin against a normal fibroblast cell line (BALB/3T3). A study on stability of trans-[PtCl2(7AI3CAH)2] in DMSO solution has been performed by FT-IR (ATR) spectroscopy to predict a possible binding mode of trans-platinum(II) complex with DNA.

A new cobalt(II) coordination polymer of indole‑3‑carboxylic acid (I3CAH2), [Co(I3CAH)2(H2O)]n has been synthesized and characterized using single-crystal X-ray diffraction, infrared spectroscopy and thermal (TGA/DTG analysis). The crystal structure is monoclinic, space group Cc, with a = 33.406(7), b = 5.9287(12), c = 8.2790(17) A, β = 91.52(3)°, V = 1639.1(6) A3 and Z = 4. Each cobalt cation is five-coordinated by the bidentate chelating indole‑3‑carboxylato ligand, one bridging oxygen atom from the other ligand in the same independent unit, one water molecule, and one bridging oxygen atom of the indole‑3‑carboxylato group from an adjacent [Co(I3CAH)2(H2O)] unit. Infrared spectra and TGA/DTG analysis of [Co(I3CAH)2(H2O)]n in the solid state support the results from X-ray analysis. Comparison of the X-ray data and the vibrational spectra of the title compound with those of the previously reported zinc(II) coordination polymer [Zn(I3CAH)2(H2O)]n has shown that these compounds are isostructural. The antifungal activity of [Co(I3CAH)2(H2O)]n against Aspergillus niger and Candida albicans has been investigated. The new Co(II) compound is remarkably effective against Candida albicans.

Despite much research on Li ion batteries at ambient temperature, Li-ion conductors at high temperature have received less attention. In the series of ionic Li2X compounds (X = O, S, Se, Te), superionic phase transitions have been reported for Li2O and Li2S. The lower transition temperature of Li2S, supposedly caused by the larger anion size of S, inspired the investigation of the superionic behavior of Li2Se and Li2Te. Their thermal expansion and thermally excited spatial distribution of Li cations and Se/Te anions was monitored by neutron diffraction up to 800 °C for Li2Te and up to 1000 °C for Li2Se. Both compounds exhibit positive thermal expansion with changing coefficient of expansivity at the superionic transition temperatures. No deviation from cubic metrics or abrupt changes of the cell volume were observed. Rietveld refinements of the fluorite-type structures (space group F m 3 ¯ m ) employing Gaussian spatial distribution functions reveal discontinuities in the slope of the increasing mean square displacement parameters as a function of temperature. At ~600 °C (Li2Te) and ~780 °C (Li2Se), the mean square displacements of Li atoms increase abruptly, indicating a superionic transition. For the Te/Se anions, similar discontinuities occur at slightly lower temperatures. Difference Fourier syntheses reveal strongly anisotropic Li spatial distribution density around the 8c (¼ ¼ ¼) positions of cubic site symmetry m 3 ¯ m . Moving the maximum of the density distribution to adjacent 32f (xxx) (site symmetry .3 m) positions introduces four virtual split atoms. In addition to the small displacement x along 〈111〉, denoting the mean positions of the split atoms, anisotropic spatial distributions may then be refined. Whereas x deviates from ¼ as an almost linear function of temperature, the abrupt changes in the increase of mean square amplitudes of thermal displacements with temperature are retained. Significantly improved profile refinement residuals support this flexible structure model. Temperature-dependent joint probability density function maps demonstrate the increasing delocalization of Li atoms and yield potential energy distributions, i.e. the energy barriers of ionic transport. The potential barrier between adjacent Li positions at the octahedral site at (½ ½ ½) shows an abrupt drop at the superionic phase transition temperature. The derivative of the potentials, i.e. the restoring forces of Li atom motions show clear deviations from linearity. The anharmonicity of thermally excited spatial atomic distribution refined using the Gram-Charlier series expansion with third- and fourth-order tensor components confirms the enhanced thermal motion in the high-temperature regime. The overall cubic crystal symmetry is maintained.

Indium-doped tin tellurides are promising and thoroughly investigated thermoelectric materials. Due to the low solubility of In 2 Te 3 in SnTe and vice versa, samples with the nominal composition (SnTe) 3-3x (In 2 Te 3 ) x with 0.136 ≤ x ≤ 0.75 consist of a defect-rocksalt-type Sn-rich and a defect-sphalerite-type In-rich phase which are endotaxially intergrown and form nanoscale heterostructures. Such nanostructures are kinetically inert and become more pronounced with increasing overall In content. The vacancies often show short-range ordering. These phenomena are investigated by temperature-dependent X-ray diffraction and HRTEM as well as STEM with element mapping by X-ray spectroscopy. The combination of real-structure effects leads to very low lattice thermal conductivity from room temperature up to 500 °C. Thermoelectric figures of merit ZT of heterostructured materials with x = 0.136 reach ZT values up to 0.55 at 400 °C.

Highly porous Ca 3 Co 4 O 9 thermoelectric oxide ceramics for high-temperature application were fabricated by sol–gel synthesis and subsequent conventional sintering. Growth mechanism of misfit-layered Ca 3 Co 4 O 9 phase, from sol–gel synthesis educts and upcoming intermediates, was characterized by in-situ X-ray diffraction, scanning electron microscopy and transmission electron microscopy investigations. The Ca 3 Co 4 O 9 ceramic exhibits a relative density of 67.7%. Thermoelectric properties were measured from 373 K to 1073 K. At 1073 K a power factor of 2.46 μW cm −1 K −2 , a very low heat conductivity of 0.63 W m −1 K −1 and entropy conductivity of 0.61 mW m −1 K −2 were achieved. The maintained figure of merit ZT of 0.4 from sol–gel synthesized Ca 3 Co 4 O 9 is the highest obtained from conventional, non-doped Ca 3 Co 4 O 9 . The high porosity and consequently reduced thermal conductivity leads to a high ZT value.

The new compound Sn 4.11(14) Bi 22.60(7) Se 38 can be obtained from the elements in high yield. It crystallizes in a structure type derived from that of K 0.66 Sn 4.82 Bi 11.18 Se 22 (space group C 2/ m , Z = 1, a = 28.141(2) A, b = 4.1820(1) A, c = 21.181(2) A, β = 131.082(9)°, R 1(obs) = 0.046). Step-like layers formally cut out of a distorted NaCl-type structure – the steps resembling Bi 2 Se 3 – are interconnected by ribbon-like building blocks that can be viewed as cutouts from the SnSe structure. Resonant X-ray scattering enabled the differentiation of the cations and revealed the presence of about 5% vacancies on cation positions. This hints at a tunable system for various applications, including such that require cation mobility.

The title compound, 1H-indazole-3-carbaldehyde, C8H6N2O (1) is important as it represents a rare example of indazole found in nature. The asymmetric unit of 1 consists of two independent molecules (1A and 1B) which are linked by N—H⋅⋅⋅O hydrogen bonds (N⋅⋅⋅O = 2.8178(15) A and 2.8203(14) A), forming one-dimensional chains. The crystal structure is stabilized by slipped face-to-face π⋅⋅⋅π interactions (Cg⋅⋅⋅Cg distances in the range 3.8492(8) – 4.1830(8) A), C=O⋅⋅⋅π interactions (O⋅⋅⋅centroids distances in the range 3.3252(12) – 3.4795(11) A) and weak non-classical C—H⋅⋅⋅N hydrogen bonds (C⋅⋅⋅N = 3.4377(18) A). 3D Hirshfeld surface analysis, 2D fingerprint plots and molecular electrostatic potentials were applied for a detailed investigation of all the interactions participating in the crystal packing. The intermolecular interactions were also confirmed by Natural Bond Orbital (NBO) analysis at the B3LYP and B3LYP-D3 levels using the 6-31++G(d,p) basis set. The energies of the intermolecular interactions (the second-order interaction energies, E2) oscillate between 55.5 kJ⋅mol−1 and 22.3 kJ⋅mol−1 for strong N−H⋅⋅⋅O hydrogen bond. The E2 value for the C=O⋅⋅⋅π and π⋅⋅⋅π interactions are about 4.9 kJ⋅mol−1 and 3.6 kJ⋅mol−1, respectively. Moreover, the strength of the hydrogen bonds was evaluated using vibrational spectroscopy (FT-IR and FT-Raman) and DFT calculations at the B3LYP level within the 6-31++G(d,p) basis set. These studies additionally confirm the presence of various intermolecular interactions in the crystal of 1.

Ceramic composites were produced by combining the oxide materials Ca3Co4−xO9+δ and La2NiO4+δ. Both compounds were characterized by a plate-like crystal shape, but crystal sizes differed by around two orders of magnitude. The composite materials could be successfully prepared by using uniaxial pressing of powder mixtures and pressureless sintering to a porous ceramic. Possible reactions between both materials during sintering were analyzed. The ceramic composites with low amounts of La2NiO4+δ showed enhanced thermoelectric properties, caused by an increasing power factor and simultaneously decreasing thermal conductivity. For the evaluation of the thermoelectric properties, two different types of Ioffe plots were utilized. The maximum figure-of-merit zT at 1073 ​K was 0.27 for the pure Ca3Co4−xO9+δ as well as for the sample containing 5 ​wt% La2NiO4+δ. However, the average Z T ¯ in the temperature range of 373 K to 1073 K could be increased by 20% for the composite material.

NiO–MgO–ZrO2 catalysts were synthesized via a melt impregnation technique on a zirconia support with equimolar amounts of Ni and Mg in the range of 2–35 mol%. The catalysts were characterized by TPDA, TPR, PXRD, TEM and EDX. The catalysts are basic in nature and contain both tetragonal and monoclinic zirconia. After impregnation, Ni and Mg are homogeneously distributed over the zirconia support in oxidic form. After reduction of the composite system, metallic Ni is highly dispersed on the support together with a solid solution of NiO–MgO present. The prepared NiO–MgO–ZrO2 catalysts show a high activity in the dry reforming of methane at 1123 K and atmospheric pressure. At high Ni and Mg contents, the catalysts are subject to severe coking leading to pronounced deactivation. From TEM investigations, a coking mechanism is proposed including the growth of filamentous carbon followed by formation of graphitic carbon, partly encapsulating metallic Ni particles. An optimum stability can be achieved in a small compositional corridor with Ni and Mg contents of 8–20 mol%. In this composition range, the presence of MgO leads to a suppression of carbon formation, especially when compared to Ni supported on Mg-free zirconia. According to their activity and stability depending on the Ni- and Mg-contents, the catalysts were assigned to three categories: (I) low activity and high stability, (II) high activity and some stability and (III) high activity, but low stability.

Sodium(I) and lithium(I) one-dimensional coordination polymers, [Na(IND3CAH)(IND3CAH2)]n (1) and [Li(IND3CAH)(H2O)]n (2), with 1H-indazole-3-carboxylic acid (IND3CAH2) have been synthesized and investigated by a single crystal X-ray diffraction and vibrational spectroscopy. In compound 1, both the O-deprotonated (IND3CAH−) and neutral (IND3CAH2) forms of the acid act as the tridentate ligands and are bound with Na+ via two oxygen atoms and the 1H-indazole nitrogen atom forming polymeric chains. Each Na+ ion is six-coordinate in a distorted octahedral geometry (NaO4N2). In compound 2, the Li+ ion is five-coordinate (LiO4N) and the coordination sphere is intermediate between square-pyramid and trigonal-bipyramid. The deprotonated IND3CAH− ion acts as the bidentate ligand coordinated to Li+ ion via one carboxylate oxygen atom and the 1H-indazole nitrogen atom. In contrast to 1, the carboxylate group exhibits the monoatomic bridging mode. In addition, the oxygen atom of the water molecule also links two adjacent Li+ ions. The bridging ligands lead to the formation of polymeric ribbons of edge-sharing O4N distorted pyramids. Intermolecular N H⋯O and O H⋯O hydrogen bonds have a distinctive effect on crystal packing of the title compounds. The IR and Raman spectra of 1 and 2 in the solid state confirm the results from X-ray analysis. Vibrational spectra of the ligand IND3CAH2 and its deuterated derivative (IND3CAD2) have been measured and assigned based on DFT calculations.

A new 2D coordination polymer of indole‑3‑acetic acid (I3AAH2) with Zn(II), [Zn(I3AAH)2]n (1) has been synthesized and fully characterized using single-crystal X-ray diffraction, infrared, Raman, 1H and 13C NMR spectroscopy, DFT calculations and microbiological activity tests. The crystal structure is monoclinic, space group P21/n, with a = 6.1948(2), b = 7.4954(3), c = 36.2877(12) A, β = 94.006(3)°, V = 1680.81(9) A3 and Z = 4. The Zn atom is bound to four oxygen atoms of four O-deprotonated I3AAH− ligands, in a slightly distorted tetrahedral environment. The carboxylate groups adopt the μ-O,O′ bidentate bridging mode. Non-classical C H⋯O intra- and intermolecular interactions provide ancillary structural stabilization of 1. A theoretical study was carried out at the B3LYP/6–31++G(d,p) level. Detailed vibrational assignment for 1 was based on the calculated PED. The in vitro antibacterial activity against Gram-negative (E. coli, P. aeruginosa) and Gram-positive (B. subtilis, L. monocytogenes and S. aureus) bacteria and in vitro antifungal activity against A. niger and C. albicans of 1 were investigated. For comparison, similar microbiological tests were performed for four other Zn(II) complexes (2–5) with indolecarboxylic acids reported earlier. For 1, the inhibition zones for bacteria were from 11 mm to 14 mm, but for fungi, no inhibition zones were observed. Promising results were obtained for 3, against B. subtilis, L. monocytogenes and A. niger and for 4 against B. subtilis (with inhibition zones >20 mm).

Lithium germanium antimony tellurides are known as promising thermoelectric materials. Earlier 7Li solid state NMR studies had revealed pronounced lithium atom mobility. Further insights into the diffusion mechanism are investigated by means of neutron powder diffraction in combination with quasielastic neutron scattering (QENS). In vacancy-containing LiGe3.5Sb2Te7, the isotropic displacement parameters of the cations are larger than in vacancy-free Li2Ge3Sb2Te7 and thus indicate more pronounced atom mobility in the investigated temperature range from room temperature to 600 °C. In contrast, temperature-dependent isotropic displacement parameters of the anions are similar for both solid solutions. Comparable to the situation in the important thermoelectric material PbTe, anharmonic displacement parameters for LiGe3.5Sb2Te7 – a lithium germanium antimony telluride with optimized thermoelectric properties – are significant already at room temperature. The extrapolation of displacement parameters toward low temperatures indicates that the displacements are predominantly dynamic. The temperature-dependent evaluation of lattice parameters and isotropic displacement parameters reveals three different regimes. From room temperature to 250 °C, a NaCl-type model with anharmonic displacement parameters for cation sites fits well. Between 250 °C and 400 °C, the unit cell volume increases less than in the other regimes and small lattice distortions may occur. At temperatures higher than 400 °C (investigated up to 600 °C), lithium atoms also occupy tetrahedral voids of the fcc Te substructure. Whereas QENS data probing the picosecond time scale show no significant lithium atom mobility in the Q range of 0.08–1.68 A−1, a temperature-dependent change in the elastic scattering term hints at a different time window or a combination of motions with different time scales.

The formation and analysis of ten microporous triazolyl isophthalate based MOFs, including nine isomorphous and one isostructural compound is presented. The compounds 1M–3M with the general formula [ M ( R 1 - R 2 - trz - ia ) ] ∞ 3 ·x H2O (M2+ = Co2+, Cu2+, Zn2+, Cd2+; R1 = H, Me; R2 = 2py, 2pym, prz (2py = 2-pyridinyle; 2pym = 2-pyrimidinyle; prz = pyrazinyle)) crystallize with rtl topology. They are available as single crystals and also easily accessible in a multi-gram scale via refluxing the metal salts and the protonated ligands in a solvent. Their isomorphous structures facilitate the synthesis of heteronuclear MOFs; in case of 2M, Co2+ ions could be gradually substituted by Cu2+ ions. The Co2+:Cu2+ ratios were determined by ICP-OES spectroscopy, the distribution of Co2+ and Cu2+ in the crystalline samples are investigated by SEM-EDX analysis leading to the conclusions that Cu2+ is more favorably incorporated into the framework compared to Co2+ and, moreover, that the distribution of the two metal ions between the crystals and within the crystals is inhomogeneous if the crystals were grown slowly. The various compositions of the heteronuclear materials lead to different colors and the sorption properties for CO2 and N2 are dependent on the integrated metal ions.

The temperature-dependent behavior of quenched single-crystalline (GeTe)nSb2Te3 (n~2.8, n~5 and n~11) was investigated by semiquantitative modeling of diffuse X-ray scattering. The structure at room temperature exhibits trigonal twin domains, each comprising a stacking-disordered sequence of distorted rocksalt-type slabs with variable thicknesses. Ge and Sb share the cation position and vacancies are partially ordered in defect layers (van der Waals gaps) between the slabs. The average structure determined with resonant diffraction data corresponds to a rocksalt-type structure whose cation position is split along the stacking direction. Upon heating, cation ordering leads to a metastable superstructure of the rocksalt type at ~400 °C, which transforms to a rocksalt-type high-temperature phase with randomly distributed cations and vacancies at ~500 °C; this structure was also refined using resonant diffraction. Cooling at high or intermediate rates does not yield the long-range ordered phase, but directly leads to the twinned disordered phase.

The crystal and molecular structure of 7-azaindole-3-carboxylic acid (7AI3CAH2) has been determined by a single-crystal X-ray diffraction analysis (space group Pca21, a = 14.247(3), b = 5.1983(10), c = 9.871(2) A, V = 731.0(2) A3, Z = 4). The crystal structure consists of chains of the 7AI3CAH2 molecules, arranged into ribbons and connected via intermolecular O–H⋯N and N–H⋯O hydrogen bonds. The IR and Raman spectra of 7AI3CAH2 and its deuterated derivative were recorded in the solid state. The DFT calculations at the B3LYP/6–311++G(d,p) level were performed for four conformers of the 7AI3CAH2 monomer as well as for the dimer and trimer, which included intermolecular H-bonding motifs. The analogous calculations were carried out for the deuterated derivative (7AI3CAD2). The optimized structural parameters and the calculated vibrational spectra of trimer reproduce the experiment very well. In addition, new complexes of 7AI3CAH2 with Pt(II) and Pd(II) were prepared and studied by infrared and Raman spectroscopy. The geometry optimizations and vibrational frequency calculations were conducted for two possible (cis and trans) isomers of [MCl2(7AI3CAH2)2] (where M = Pt(II) or Pd(II)) using the B3LYP method with the 6–311++G(d,p)/LanL2DZ basis sets. The combined experimental and theoretical vibrational spectroscopic studies have shown that in the solid state the platinum(II) complex exists as the cis isomer (cis-[PtCl2(7AI3CAH2)2]), whereas the palladium(II) complex has the trans conformation (trans-[PdCl2(7AI3CAH2)2]). In both isomers, two pyridine nitrogen atoms of the 7AI3CAH2 ligands and two chloride ligands are coordinated to the central Pt(II) or Pd(II) atoms in a square-planar arrangement. The carboxylic and NH groups of 7AI3CAH2 are not bonded by metal ions. Detailed vibrational assignments for 7AI3CAH2 and its Pt(II) and Pd(II) complexes have been made on the basis of the calculated potential energy distributions (PEDs). The in vitro antiproliferative activities of cis-[PtCl2(7AI3CAH2)2] and trans-[PdCl2(7AI3CAH2)2] were studied on two human cancer cell lines (T47D and A549). As follows from the obtained IC50 values, the trans-[PdCl2(7AI3CAH2)2] complex exhibits cytotoxicity against T47D cell line, which is comparable to that of cisplatin.

A superstructure of the rocksalt-type observed in quenched CVT-grown single crystals of Ge3.25(7)Sn1.10(3)Sb1.10(3)Te6 was elucidated by X-ray diffraction using fourfold twinned crystals (space group P 3 ¯ m 1 , a=4.280(1) A, c=20.966(3) A). The structure is built up of distorted rocksalt-type building blocks typical for long-range ordered GST materials and substitution variants thereof. In contrast to those phases, an exclusive ABC-type cubic stacking sequence of the Te-atom layers is present. High-resolution electron microscopy reveals spheroidal domains with this structure (average diameter 25 nm) whose stacking direction is perpendicular to the 〈1 1 1〉 directions of the basic rocksalt-type structure. Additional slab-like domains with a lateral extension up to 1 µm occasionally result in a hierarchical structure motif. Due to the similar electron counts of the elements involved, resonant diffraction was used in order to elucidate the element distribution in rocksalt-type building blocks of the stable layered compound 39R-Ge3SnSb2Te7 ( R 3 ¯ m , a=4.24990(4) A, c=73.4677(9) A). Sb tends to occupy the atom site close to the van der Waals gaps while Ge concentrates in the center of the building blocks.

Eight platinum(II) complexes of the general formula cis-[PtCl2(L)2] containing 7-azaindole (L = 7AIH) and its halogeno-derivatives: L = 3-chloro-7-azaindole (3Cl7AIH); 3-bromo-7-azaindole (3Br7AIH); 4-chloro-7-azaindole (4Cl7AIH); 4-bromo-7-azaindole (4Br7AIH); 5-bromo-7-azaindole (5Br7AIH); 3-bromo-4-chloro-7-azaindole (3Br4Cl7AIH) and 5-bromo-3-chloro-7-azaindole (5Br3Cl7AIH) were prepared. Two complexes, cis-[PtCl2(3Br4Cl7AIH)2] (2) and cis-[PtCl2(4Br7AIH)2]·DMF, are reported for the first time. Crystal structure of the latter compound has been determined with X-ray diffraction analysis (space group P43, with a = 14.775(2), c = 41.640(8) A, V = 9090(3) A3 and Z = 16). For all of these complexes, formation of the cis isomers in the solid state was confirmed by experimental vibrational (IR and Raman) spectroscopy combined with DFT calculations. A complete assignment of the IR and Raman spectra was made on the basis of the calculated potential energy distribution (PED). Stability of complex (2) in DMSO solution was investigated by FT-IR (ATR) spectroscopy. The in vitro antiproliferative activity of cis-[PtCl2(3Br4Cl7AIH)2], cis-[PtCl2(3Cl7AIH)2] and cis-[PtCl2(3Br7AIH)2] was evaluated on selected human cancer cell lines and towards normal mouse fibroblast cell line (BALB/3T3). All complexes are more toxic than cisplatin against Es-2 (ovarian cancer), LNCaP (prostate adenocarcinoma) and MCF7 (breast cancer). Moreover, complex (2) is significantly more active than the other complexes on A549 (lung carcinoma, IC50 = 3.9 μM). However, the three investigated Pt(II) complexes with 7-azaindoles have revealed higher cytotoxicity against a normal cell line (BALB/3T3), in comparison to cisplatin.

Antimony in germanium antimony tellurides (GeTe)n(Sb2Te3) can be substituted by indium. Homogeneous bulk samples of GeSbInTe4 (R3m, Z=3, a=4.21324(5) A, c=41.0348(10) A) and Ge2SbInTe5 (P3m1, Z=1, a=4.20204(6) A, c=17.2076(4) A) were obtained; their structures were refined with the Rietveld method. Single-crystal X-ray diffraction using synchrotron radiation at the K edges of Sb and Te (exploiting anomalous dispersion) yields precise information on the element distribution in the trigonal layered structure of Ge3SbInTe6 (R3m, Z=3, a=4.19789(4) A, c=62.1620(11) A). The structure is characterized by van der Waals gaps between distorted rocksalt-type slabs of alternating cation and anion layers. The cation concentration is commensurately modulated with Sb preferring the positions near the gaps. In contrast to unsubstituted Ge3Sb2Te6, quenching the NaCl-type high-temperature phase (stable above ~510 °C) easily yields a pseudocubic modification that is metastable at ambient conditions. Temperature-dependent powder diffraction reveals a broader stability range of the cubic high-temperature modification of Ge3SbInTe6 compared to the ternary phases. In-containing samples partially decompose at ca. 300 °C but become homogeneous again when the high-temperature phase is formed.

Quenching rocksalt-type high-temperature phases of members of the solid solution series Ge12M2Te15 (M = Sb, In) results in nanostructured (pseudo-)cubic materials as shown by high-resolution electron microscopy. The transition temperatures between the thermodynamically stable trigonal phases and the cubic high-temperature phases decrease with increasing In content. Due to a pronounced increase of the Seebeck coefficient, the thermoelectric figure of merit (ZT) of Ge12SbInTe15 (average structure: F m 3 ¯ m , a = 5.9603(1), RBragg = 0.024) is higher than that of Ge12Sb2Te15 up to 300 °C. This effect is even more pronounced for metastable Ge12In2Te15 (average structure: F m 3 ¯ m , a = 5.94723(4), RBragg = 0.048).

Metastable rocksalt-type phases of the solid solution series AgInxSb1−xTe2 (x=0.1, 0.2, 0.4, 0.5 and 0.6) were prepared by high-pressure synthesis at 2.5 GPa and 400 °C. In these structures, the coordination number of In3+ is six, in contrast to chalcopyrite ambient-pressure AgInTe2 with fourfold In3+ coordination. Transmission electron microscopy shows that real-structure phenomena and a certain degree of short-range order are present, yet not very pronounced. All three cations are statistically disordered. The high degree of disorder is probably the reason why AgInxSb1−xTe2 samples with 0.4

Sr0.5Ba0.5Si2O2N2:Eu2+ is a promising new phosphor for white light phosphor converted (pc)—LEDs. The material shows broad-band emission due to parity allowed 4f6(7F)5d → 4f7(8S7/2) transition in the yellow spectral range (λem ≈ 560 nm) while excited with UV to blue radiation. The X-ray powder diffraction pattern shows noticeable intensity maxima indicative for diffuse scattering from planar defects and also “missing” reflections compared to SrSi2O2N2:Eu2+. Rietveld refinement reveals an average structure of Sr0.5Ba0.5Si2O2N2:Eu2+ which is isotypic to that of SrSi2O2N2:Eu2+, with the latter representing a twinned layered oxonitridosilicate with disordered metal atoms. The average structure of Sr0.5Ba0.5Si2O2N2:Eu2+ was refined in space group P1 (no. 1) resulting in lattice parameters a = 7.2059(2), b = 7.3887(3), c = 7.3340(2) A, α = 88.524(4), β = 84.454(3), γ = 75.980(4)° and V = 377.07(2) A3. Based on the crystallographic results and considering lattice relaxation behavior as a consequence of lattice expansion, the observed unexpectedly large Stokes shift (as compared to SrSi2O2N2:Eu2+; 3573 vs. 3285 cm−1) can be explained using a least square fit of the emission spectra. With almost identical chromaticity coordinates with respect to the most frequently used commercial LED phosphor YAG:Ce3+ but significantly higher luminous efficacy (LE = 495 lm/W), Sr0.5Ba0.5Si2O2N2:Eu2+ is a promising material for outdoor lighting, e.g. in cool-white pc-LEDs. To elucidate the real structure, powder XRD simulations have been recorded compiling a disorder model taking into account all permutations of metal ion sets and silicate layer orientations. Experimental diffraction data were well reproduced including the diffuse intensities observed in powder XRD and also in SAED patterns. These simulations show that crystallites of Sr0.5Ba0.5Si2O2N2:Eu2+ are built up of small anti-phase domains within larger twin domains.

The atom distribution in SnSb 2 Te 4 ( R 3 ¯ m , a = 4.298(1), c = 41.57(1) A) has been elucidated by resonant single-crystal diffraction using synchrotron radiation with wavelengths near the K absorption edges of the elements present and additional non-resonant data. Refinement of site occupancies for all atoms on all sites was done with a joint refinement using five datasets. It shows that there is almost no anti-site disorder and no significant amount of vacancies. The cations are neither fully ordered nor randomly distributed. The 21 R -type structure consists of rocksalt-type blocks separated by van der Waals gaps. Each block consists of four anion and three cation layers. Sn atoms are distributed over all cation sites but cluster in the middle of the blocks.

Single crystals of the orthoborate {pi}-ErBO{sub 3} were synthesized from Er{sub 2}O{sub 3} and B{sub 2}O{sub 3} under high-pressure/high-temperature conditions of 2 GPa and 800 {sup o}C in a Walker-type multianvil apparatus. The crystal structure was determined on the basis of single-crystal X-ray diffraction data, collected at room temperature. The title compound crystallizes in the monoclinic pseudowollastonite-type structure, space group C2/c, with the lattice parameters a=1128.4(2) pm, b=652.6(2) pm, c=954.0(2) pm, and {beta}=112.8(1){sup o} (R{sub 1}=0.0124 and wR{sub 2}=0.0404 for all data). -- graphical abstract: The first satisfying single-crystal structure determination of {pi}-ErBO{sub 3} sheds light on the extensively discussed structure of {pi}-orthoborates. The application of light pressure during the solid state synthesis yielded in high-quality crystals, due to pressure-induced crystallization. Research highlights: {yields} High-quality single crystals of {pi}-ErBO{sub 3} were prepared via high-pressure-induced crystallization. {yields} At least five different space groups for the rare-earth {pi}-orthoborates are reported. {yields} {pi}-ErBO{sub 3} is isotypic to the pseudowollastonite-type CaSiO{sub 3}. {yields} Remaining ambiguities regarding the structure of the rare-earth {pi}-orthoborates are resolved.

The first lanthanum fluoride borate La{sub 4}B{sub 4}O{sub 11}F{sub 2} was obtained in a Walker-type multianvil apparatus at 6 GPa and 1300 {sup o}C. La{sub 4}B{sub 4}O{sub 11}F{sub 2} crystallizes in the monoclinic space group P2{sub 1}/c with the lattice parameters a=778.1(2) pm, b=3573.3(7) pm, c=765.7(2) pm, {beta}=113.92(3){sup o} (Z=8), and represents a new structure type in the class of compounds with the composition RE{sub 4}B{sub 4}O{sub 11}F{sub 2}. The crystal structure contains BO{sub 4}-tetrahedra interconnected with two BO{sub 3}-groups via common vertices, B{sub 2}O{sub 5}-pyroborate units, and isolated BO{sub 3}-groups. The structure shows a wave-like modulation along the b-axis. The crystal structure and properties of La{sub 4}B{sub 4}O{sub 11}F{sub 2} are discussed and compared to Gd{sub 4}B{sub 4}O{sub 11}F{sub 2}. - Graphical abstract: A new structure type of RE{sub 4}B{sub 4}O{sub 11}F{sub 2}: high-pressure synthesis and crystal structure of La{sub 4}B{sub 4}O{sub 11}F{sub 2}.

BaSi2O2N2 is a promising host lattice for rare-earth doped luminescent materials in phosphor-converted (pc)-LEDs. Applying a combined approach, its orthorhombic average structure (space group Cmcm (no. 63), a = 14.3902(3) A, b = 5.3433(1) A, c = 4.83256(7) A and V = 371.58(2) A3, Z = 4) has been elucidated by electron diffraction and structure solution from X-ray and neutron powder diffraction data with subsequent Rietveld refinement (wRp = 0.0491 for X-ray data). The structure contains layers of highly condensed SiON3 tetrahedra with O terminally bound to Si. The Ba2+ ions are situated between the layers and are surrounded by a cuboid of O atoms capped by two N atoms. In the structure, there is only one Ba site and one Si site, respectively, which is in accordance with a single sharp 29Si NMR signal observed at −52.8 ppm typical for SiON3 tetrahedra in MSi2O2N2 type oxonitridosilicates. Lattice energy calculations support the results of the structure determination.

Tetrathallium(I) tetra-μ-imidocyclotetraphosphate monohydrate, Tl4(PO2NH)4·H2O, was obtained by evaporation of combined aqueous solutions of K4(PO2NH)4·4H2O and TlOOCCH3 corresponding to the molar ratio of 1:4. The structure determination of Tl4(PO2NH)4·H2O was performed by single-crystal X-ray diffraction methods. In addition to the basic structure ( P 1 ¯ , no. 2, a = 928.3(2), b = 974.6(2), c = 1018.0(2) pm, α = 74.47(3)°, β = 64.68(3)°, γ = 78.81(3)°, Z = 2), satellite reflections indicate a fourfold superstructure ( A 1 ¯ , a = 928.0(2), b = 3897.1(8), c = 2035.4(4), α = 74.47(3)°, β = 64.68(3)°, γ = 78.81(3)°, Z = 16) that is described by an a × 4b × 2c, A-centered supercell which mainly concerns one thallium site of the basic structure. In order to reduce the number of parameters, this superstructure was handled as a commensurate occupancy modulation using the structural description in (3 + 1)-dimensional superspace ( P 1 ¯ ( α β γ ) , q = 0.25b∗ + 0.5c∗). The crystal structure of Tl4(PO2NH)4·H2O consists of infinite columns of the cyclic [(PO2NH)4]4− anions (saddle conformation) which are interconnected by four N–H⋯O hydrogen bonds. By coordination to the Tl+ ions the [(PO2NH)4]4− columns form a three-dimensional network with channels along [100] wherein the thallium ions that are mainly affected by the modulation are located. The commensurate occupancy modulation of these Tl+ ions has been described with a single harmonic wave function. The modulation is verified by 31P NMR spectroscopy. The thermal behavior of Tl4(PO2NH)4·H2O and the IR data are discussed as well.

The crystal structures of the intermediate solid solution HT (high temperature) Ni1+δSn with δ=0.28, 0.52 and 0.61 (refined Ni contents) have been analyzed in detail by X-ray diffraction on single crystals. The previously reported basic atomic arrangement, i.e., a NiAs/Ni2In structure type (P63/mmc, Ni(1) on 2a, 0 0 0, Ni(2) with an occupancy δ on 2d, 2 3 1 3 1 4 , and Sn on 2c, 1 3 2 3 1 4 ), is confirmed. However, strong anisotropic atomic displacements occur for Sn within the a–b plane of the hexagonal unit cell, which require a Gram-Charlier expansion of the probability density function of Sn in order to obtain a good fit to the diffraction data. Direction, magnitude and the concentration dependence of the displacements can be interpreted in terms of the geometrical requirements of the different local atomic configurations in the planes z=±1/4, so that the displacements can be identified as static ones.

A simple synthetic procedure leading to the V2(S2)2(RCS2)4 species (R=Et2N (1), cyclo-C4H8N (2), n-Bu2N (3), EtO (4), i-PrO (5)) has been developed. X-ray structures of 3 and 5 have been reported, featuring the centrosymmetric molecules with VV distances 2.850(3) A for 3 and 2.838(2) A for 5.The FAB mass spectra were recorded. In all cases molecular peaks are observed. Fragmentation patterns are discussed.

Pr8Cl7B7 is prepared from stoichiometric mixtures of PrCl33, Pr and B at 1220 K in closed Ta capsules. Pr8Cl7B7 forms golden coloured needles sensitive to moist air. It crystallizes in the space group P1 with a = 773.1(2) pm, b = 903.0(2) pm, c = 1419.4(3) pm, a = 81.55(3)°, β = 82.18(3)°, and γ = 64.76(3)°. In the crystal structure Pr6 trigonal prisms are condensed to double chains which run parallel [100]. Some of the prisms and rectangular prism faces are centered by boron atoms which leads to B3, B6, B8 rings, and B2 dumbbells condensed into ribbons. These Pr8B7 strands are surrounded and held together by the Cl atoms. Pr8Cl7B7 is a metallic conductor and shows Curie Weiss behavior with μeff = 3.48 μB. According to extended Huckel calculations, the distribution of valence electrons is best described by a formulation Pr818+Cl77−B711−. Bonding within the boron ribbons is thus nearly optimal, while the average 4f2 5d3/4 configuration of Pr accounts for both the observed magnetic moment and metallic conductivity.

In this review we describe a variety of rare earth metal boride halides and boride carbide halides. In boride halides boron atoms occur either as discrete atoms octahedrally coordinated by rare earth metal atoms or as chains of interconnected B 4 rhomboids in rods of fused metal atom bisphenoids. Characteristic building units in boride carbide halides are quasi-molecular B–C, C–B–C, C–B–B–C, and C 2 –B–B–C 2 entities. In these compounds B centers trigonal prisms of rare earth metal atoms, and C is located in tetragonal pyramids. Owing to the electropositive character of rare earth metals, B atoms, B 4 units, and C n B m groups tend to be anions. Band structure calculations as well as electrical and magnetic measurements have been performed. The compounds show semiconducting or metallic behavior, depending on whether excess electrons according to the Zintl–Klemm formalism are localized or delocalized. La 9 Br 5 (CBC) 3 is superconducting with T c ∼6 K. Ce and Gd compounds are paramagnetic. In most cases anti-ferromagnetic ordering is observed at low temperature.