http://www.mdpi.com/journal/crystals Latest open access articles published in Crystals at http://www.mdpi.com/journal/crystals/ http://www.mdpi.com/2073-4352/2/1/96/ The crystal structures of four salts of 1,4-diazabicyclo[2.2.2]octane (DABCO) and 5-aminotetrazole are described. Anhydrous 1:1 (Pbca, Rgt = 0.041) and 1:2 (P, Rgt = 0.038) salts form hydrogen-bonded layers of anions and cations. The monohydrate of the 1:1 compound (P21/c, Rgt = 0.038) shows infinite chains of DABCO cations and an undulated layer of anions and water molecules. The octahydrate of the 3:2 compound (P21/c, Rgt = 0.042) features DABCO triples and clusters of four tetrazolate ions in a network of water molecules. http://www.mdpi.com/2073-4352/2/1/96/ Mon, 06 Feb 2012 00:00:00 CET Crystals 2012-02-06 2 1 Article 96 104 2073-4352 1,4-Diazabicyclo[2.2.2]octane (DABCO) 5-aminotetrazolates 2012-02-06 doi: 10.3390/cryst2010096 Gerhard Laus Volker Kahlenberg Klaus Wurst Michael Hummel Herwig Schottenberger http://www.mdpi.com/2073-4352/2/1/90/ The crystal and molecular structure of tert-butyl 4-(2-tert-butoxy-2-oxoethyl)-piperazine-1-carboxylate is reported. The title compound crystallizes from a petroleum ether/ethyl acetate mixture in the monoclinic space group P 21/c with four molecules in the unit cell. The unit cell parameters are: a = 8.4007(2) Å, b = 16.4716(4) Å, c = 12.4876(3) Å; β = 90.948(1)° and V = 1727.71(7) Å3. Bond lengths and angles of this piperazine-carboxylate are typical. http://www.mdpi.com/2073-4352/2/1/90/ Mon, 06 Feb 2012 00:00:00 CET Crystals 2012-02-06 2 1 Communication 90 95 2073-4352 Synthesis and Molecular Structure of tert-Butyl 4-(2-tert-butoxy-2-oxoethyl)piperazine-1-carboxylate 2012-02-06 doi: 10.3390/cryst2010090 Constantin Mamat Anke Flemming Martin Köckerling http://www.mdpi.com/2073-4352/2/1/78/ This article investigates hole transport in poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV)/CdSe colloidal quantum dot (CQD) nanocomposites using a modified time-of-flight photoconductivity technique. The measured hole drift mobilities are analyzed in the context of Bässler’s Gaussian disorder model and the correlated disorder model in order to determine the polymer internal morphology of hybrid nanocomposite thin films. This work shows that increasing the CdSe CQD concentration decreases the polymer hole mobility from ~5.9 × 10−6 cm2/Vs in an MEH-PPV film to ~8.1 × 10−8 cm2/Vs in a 20:80 (wt%) MEH-PPV:CdSe CQD nanocomposite film (measured at 25 °C and ~2 × 105 V/cm). The corresponding disorder parameters indicate increasing disruption of interchain interaction with increasing CQD concentration. This work quantifies polymer chain morphology in hybrid nanocomposite thin films and provides useful information regarding the optimal use of semiconductor nanocrystals in conjugated polymer-based optoelectronics. http://www.mdpi.com/2073-4352/2/1/78/ Mon, 16 Jan 2012 00:00:00 CET Crystals 2012-01-16 2 1 Article 78 89 2073-4352 Influence of Semiconductor Nanocrystal Concentration on Polymer Hole Transport in Hybrid Nanocomposites 2012-01-16 doi: 10.3390/cryst2010078 Ryan Pate Adrienne D. Stiff-Roberts http://www.mdpi.com/2073-4352/2/1/56/ Dynamics of photoinduced phase transitions in molecular conductors are reviewed from the perspective of interplay between correlated electrons and phonons. (1) The charge-transfer complex TTF-CA shows a transition from a neutral paraelectric phase to an ionic ferroelectric phase. Lattice phonons promote this photoinduced transition by preparing short-range lattice dimerization as a precursor. Molecular vibrations stabilize the neutral phase so that the ionic phase, when realized, possesses a large ionicity and the Mott character; (2) The organic salts θ-(BEDT-TTF)2RbZn(SCN)4 and α-(BEDT-TTF)2I3 show transitions from a charge-ordered insulator to a metal. Lattice phonons make this photoinduced transition hard for the former salt only. Molecular vibrations interfere with intermolecular transfers of correlated electrons at an early stage; (3) The organic salt κ-(d-BEDT-TTF)2Cu[N(CN)2]Br shows a transition from a Mott insulator to a metal. Lattice phonons modulating intradimer transfer integrals enable photoexcitation-energy-dependent transition pathways through weakening of effective interaction and through introduction of carriers. http://www.mdpi.com/2073-4352/2/1/56/ Fri, 06 Jan 2012 00:00:00 CET Crystals 2012-01-06 2 1 Review 56 77 2073-4352 Theory of Photoinduced Phase Transitions in Molecular Conductors: Interplay Between Correlated Electrons, Lattice Phonons and Molecular Vibrations 2012-01-06 doi: 10.3390/cryst2010056 Kenji Yonemitsu http://www.mdpi.com/2073-4352/2/1/43/ New radical cation salts (BEDT-TTF)[8,8',(7)-Cl2(Cl0.09)-3,3'-Co(1,2-C2B9H9.91)(1',2'-C2B9H10)] (1), (BEDT-TTF)[8,8'-Br0.75Cl1.25-3,3'-Co(1,2-C2B9H10)2] (2), and (BMDT-TTF)4[8,8'-Br1.16(OH)0.72-3,3'-Co(1,2-C2B9H10.06)2] (3) were synthesized, and their crystal structures and electrical conductivities were determined. All the radical cation salts are semiconductors. Compounds 1 and 2 were found to be isostructural, however their electrical conductivities strongly differ (s293 = 2 Ω−1cm−1 and 10−5 Ω−1cm−1, respectively). http://www.mdpi.com/2073-4352/2/1/43/ Fri, 06 Jan 2012 00:00:00 CET Crystals 2012-01-06 2 1 Article 43 55 2073-4352 New Fulvalenium Salts of Cobalt Bis(dicarbollide): Crystal Structures and Electrical Conductivities 2012-01-06 doi: 10.3390/cryst2010043 Olga N. Kazheva Grigory G. Aleksandrov Andrey V. Kravchenko Vladimir A. Starodub Irina A. Lobanova Irina D. Kosenko Igor B. Sivaev Vladimir I. Bregadze Lev I. Buravov Oleg A. Dyachenko http://www.mdpi.com/2073-4352/2/1/34/ The title compound [H2NNHC(NH2)2]2[C6HO2(NO2)3] (2) was prepared in 85% yield by treatment of sodium styphnate with 2 equivalents of aminoguanidinium nitrate, followed by crystallization from aqueous solution. Compound 2 crystallizes in the triclinic space group Pī with unit cell dimensions a = 6.7224(3) Å, b = 10.7473(4) Å, c = 11.9604(5) Å, α = 113.212(4)°, β = 90.579(3)°, γ = 99.815(3)°, V = 779.68(6) Å3, Z = 2. In the solid state structure of 2, no water of crystallization is present. Bond angles within the aromatic ring of the styphnate anion indicate a significant distortion with larger angles (122.04(18)–125.96(18) Å) at the carbons bearing the nitro groups, and smaller ones (113.30(17) and 114.07(17) Å) at the C-O− carbon atoms. The crystal structure of 2 consists of layers formed by an extensive network of N-H...O hydrogen bonds between NH2 groups of the aminoguanidinium cation and the negatively charged oxygens of the styphnate anion. The layers are again interconnected by N-H...N hydrogen bonds between neighboring aminoguanidinium cations. http://www.mdpi.com/2073-4352/2/1/34/ Wed, 04 Jan 2012 00:00:00 CET Crystals 2012-01-04 2 1 Article 34 42 2073-4352 Molecular and Crystal Structure of a New High Energy Density Material: Aminoguanidinium-styphnate, [H2NNHC(NH2)2]2[C6HO2(NO2)3] 2012-01-04 doi: 10.3390/cryst2010034 Raik Deblitz Cristian G. Hrib Georg Plenikowski Frank T. Edelmann http://www.mdpi.com/2073-4352/2/1/22/ The possibility of substituting Pt/C with the hydrogen storage alloy MlNi3.6Co0.85Al0.3Mn0.3 as the anode active material of a proton exchange membrane fuel cell system has been analyzed. The electrochemical properties indicate that a much more electrochemically active anode is obtained by impregnating the active material loaded anode in a Nafion proton conducting polymer. Such performance improvement might result from the increase of three-phase boundary sites or length in the gas diffusion electrode where the electrochemical reaction occurs. The experimental data revealed that the membrane electrode assembly (MEA) shows better results when the anode active material, MlNi3.6Co0.85Al0.3Mn0.3, is treated with a hot alkaline KBH4 solution, and then chemically coated with 3 wt.% Pd. The MEA with the aforesaid modification presents an enhanced surface capability for hydrogen adsorption, and has been studied by molecular beam-thermal desorption spectrometry. http://www.mdpi.com/2073-4352/2/1/22/ Wed, 28 Dec 2011 00:00:00 CET Crystals 2011-12-28 2 1 Article 22 33 2073-4352 Studies of Modified Hydrogen Storage Intermetallic Compounds Used as Fuel Cell Anodes 2011-12-28 doi: 10.3390/cryst2010022 Yun Chen Diogo M. F. Santos César A. C. Sequeira Rui F. M. Lobo http://www.mdpi.com/2073-4352/2/1/1/ A systematic investigation of phase transitions in unmilled and milled LiBH4 has been performed by Pressurized Differential Scanning Calorimetry (PDSC). It was found that a large exotherm is present below the low temperature (LT) → high temperature (HT) phase transition. This exotherm is not caused by air contamination but seems to originate from hydrogen release from a solid solution in the matrix of LiBH4 low temperature phase. The exotherm activation energy has been measured to be 100 kJ mol–1. Calorimetric measurements under argon and hydrogen have shown that for the milled sample, the endothermic peak of the LT → HT transition is split in two when the PDSC scan is performed under hydrogen atmosphere. Synchrotron X-ray powder diffraction on the milled LiBH4 sample revealed only a single-step transition from the LT to HT phase, both under vacuum and under 2 and 40 bar of hydrogen pressure. The axial ratios for the LT LiBH4 below 300 K are significantly altered by milling; they are also considerably different under 40 bar of hydrogen, indicating an interaction between the hydrogen gas and the LT LiBH4 solid phase. http://www.mdpi.com/2073-4352/2/1/1/ Tue, 27 Dec 2011 00:00:00 CET Crystals 2011-12-27 2 1 Article 1 21 2073-4352 Differential Scanning Calorimetry (DSC) and Synchrotron X-ray Diffraction Study of Unmilled and Milled LiBH4: A Partial Release of Hydrogen at Moderate Temperatures 2011-12-27 doi: 10.3390/cryst2010001 J. Lang A. Gerhauser Y. Filinchuk T. Klassen J. Huot http://www.mdpi.com/2073-4352/1/4/254/ The base catalyzed intramolecular nucleophilic cyclization of 1-(2-bromobenzoyl)-3-(2-fluorophenyl)thiourea (1) in the presence of N,N-dimethyl formamide (DMF) afforded the 1-(3-fluorophenyl)-2-thioxo-2,3-dihydroquinazolin-4(1H)-one (2) by an intramolecular nucleophilic substitution SNAr mechanism. The structure was supported by the spectroscopic data and unambiguously confirmed by the single crystal X-ray diffraction data. It crystallizes in the orthorhombic space group P na21 with unit cell dimensions a = 22.430(4), b = 8.1478(16), c = 13.522(3) Å, V = 2471.2(9) Å3. There are two independent molecules per asymmetric unit that are linked to centrosymmetric AB-dimers via intermolecular N-H…S bonds. http://www.mdpi.com/2073-4352/1/4/254/ Thu, 08 Dec 2011 00:00:00 CET Crystals 2011-12-08 1 4 Communication 254 259 2073-4352 Synthesis and Crystal Structure of 1-(3-Fluorophenyl)-2-thioxo-2,3-dihydroquinazolin-4(1H)-one 2011-12-08 doi: 10.3390/cryst1040254 Aamer Saeed Ulrich Flörke http://www.mdpi.com/2073-4352/1/4/244/ The rare-earth metal(III) ortho-oxomolybdates with the formula Ln0.667[MoO4] (Ln = Ce, Pr, Nd, and Sm) and defect scheelite-type structure crystallize in the tetragonal space group I41/a (a = 533–525, c = 1183–1158 pm) with four formula units per unit cell. The Ln3+ cations at Wyckoff position 4b exhibit a coordination sphere of eight oxygen atoms in the shape of a trigonal dodecahedron. The same site symmetry (..) is observed for the tetrahedral oxomolybdate(VI) entities [MoO4]2–, since their central Mo6+ cation is situated at the 4a position. Due to this equal site multiplicity, the lanthanoid(III) cations have to be statistically under-occupied to maintain electroneutrality, thus a defect scheelite structure emerges. The partial structure of both the Ln3+ cations and the [MoO4]2– anions (if shrunk to their centers of gravity) can be best described as distorted diamond-like arrangements. Therefore, these two interpenetrating partial structures exhibit a similar setup as found in the zircon-type as well as in the NaTl-type structure. http://www.mdpi.com/2073-4352/1/4/244/ Mon, 05 Dec 2011 00:00:00 CET Crystals 2011-12-05 1 4 Article 244 253 2073-4352 Defect Scheelite-Type Lanthanoid(III) Ortho-Oxomolybdates(VI) Ln0.667[MoO4] (Ln = Ce, Pr, Nd, and Sm) and Their Relationship to Zircon and the NaTl-Type Structure 2011-12-05 doi: 10.3390/cryst1040244 Tanja Schustereit Sabine L. Müller Thomas Schleid Ingo Hartenbach http://www.mdpi.com/2073-4352/1/4/236/ The crystal structures of C5H14N2·HPO3·H2O (1) and C5H14N2·HPO3·2.23H2O (2) are described and compared. Compound 1 contains homochiral (S)-2-methyl piperizinium cations, hydrogen phosphite ions and water molecules. The components are linked by N–H⋯O and O–H⋯O hydrogen bonds into a three-dimensional network. In compound 2, racemic (R,S)-2-methyl piperizinium cations combine with the same anions and water molecules to generate a far more complex, high symmetry “supramolecular” structure, which features distinctive R66(12) loops and helical C(2) chain hydrogen-bonding motifs involving the water molecules. Crystal data: 1 (C5H17N2O4P), Mr = 200.18, orthorhombic, P212121 (No. 19), Z = 4, a = 8.564 (5) Å, b = 9.593 (6) Å, c = 11.607 (6) Å, V = 953.6 (9) Å3, R(F) = 0.066, wR(F2) = 0.081. 2 (C5H19.47N2O5.24P), Mr = 222.49, trigonal, (No. 148), Z = 18, a = 31.075 (2) Å, c = 6.1875 (4) Å, V = 5174.5 (6) Å3, R(F) = 0.044, wR(F2) = 0.107. http://www.mdpi.com/2073-4352/1/4/236/ Thu, 17 Nov 2011 00:00:00 CET Crystals 2011-11-17 1 4 Short Note 236 243 2073-4352 Supramolecular Hydrogen-Bond Motifs in Chiral and Racemic Molecular Salts: A Comparison of (S)-2-Methyl Piperizinium Hydrogen Phosphite Monohydrate, C5H14N2·HPO3·H2O and (R,S)-2-Methyl Piperizinium Hydrogen Phosphite 2.23 Hydrate, C5H14N2·HPO3·2.23H2O 2011-11-17 doi: 10.3390/cryst1040236 William T. A. Harrison http://www.mdpi.com/2073-4352/1/4/229/ The crystal and molecular structure of the title compound, viz., (2Z)-2-[3-(4-methoxybenzoyl)-4,4-dimethyl-1,2,-oxazolidin-2-ylidene]-1-(4-methoxyphenyl)ethanone (4), is reported. Compound 4 crystallises from toluene/hexanes mixtures in the P21/c space group with eight molecules in the unit cell. The unit cell parameters are: a = 20.9410(11) Å, b = 8.7523(5) Å, c = 21.2291(9) Å; β = 93.529(3)° and V = 3883.5(3) Å3. There are two structurally distinct molecules of 4 found in the solid-state which differ primarily in terms of the observed torsion angles and the overall intramolecular spacing between the aromatic groups. Bond lengths and angles of this tertiary amide are otherwise typical. This is the first crystallographically characterised example of this class of oxazoline precursors, which have previously found application in the syntheses of other heterocycles. Density functional theory (b3lyp 6-311++G** level of sophistication) has likewise been applied to estimate the gas-phase structure of the title compound. http://www.mdpi.com/2073-4352/1/4/229/ Mon, 31 Oct 2011 00:00:00 CET Crystals 2011-10-31 1 4 Article 229 235 2073-4352 The Crystal and Molecular Structure of (2Z)-2-[3-(4-Methoxybenzoyl)-4,4-dimethyl-1,2-oxazolidin-2-ylidene]-1-(4-methoxyphenyl)ethanone 2011-10-31 doi: 10.3390/cryst1040229 Anna Petrov Roderick C. Jones Douglas G. Vaughan Alan J. Lough Robert A. Gossage http://www.mdpi.com/2073-4352/1/4/220/ The reaction of bismuth triiodide with iodine and benzo-15-crown-5 in ethanol/dichloromethane yielded red single crystals of (b15c5)BiI3(I2) (monoclinic, P21/c (no. 14), a = 1376.9(1), b = 1172.7(1), c = 1700.2(2) pm, b = 115.197(6), V = 2484.1(4)·106 pm3, Z = 4). Neutral pseudo-octahedral complexes (b15c5)BiI3 are connected by secondary bonding interactions via iodine molecules to chains. Electronic structure calculations of the neutral complex (b15c5)BiI3 reveal that the compound can indeed be described as b15c5 interacting with a molecular BiI3 unit. However, bonding has to be mainly electrostatic as the interactions of the bismuth 6s lone pair with the 2p orbitals of the oxygen atoms of the crown ether are clearly antibonding. http://www.mdpi.com/2073-4352/1/4/220/ Mon, 24 Oct 2011 00:00:00 CEST Crystals 2011-10-24 1 4 Article 220 228 2073-4352 (B15c5)BiI3(I2): Molecular Benzo-15-Crown-5―BiI3 Complexes Bridged by Iodine Molecules to Chains 2011-10-24 doi: 10.3390/cryst1040220 Christoph Fiolka Mark Richter Ingo Pantenburg Anja-Verena Mudring Gerd Meyer http://www.mdpi.com/2073-4352/1/4/215/ A reaction of YI3, dibenzo-24-crown-8 and iodine in ethanol yielded, as a by-product, red single crystals of (I2)@(db24c8). In the triclinic crystal, P-1, a = 485.0(1), b = 1203.7(3), c = 1280.4(2) pm, α = 64.56(2)°, β = 86.82(2)°, γ = 83.89(2)°, V = 671.1(2) × 106.pm3, Z = 1, R1= 0.0301 for 1965 reflections with I0 > 2σ(I0), iodine molecules with an I–I distance of 268.39(7) pm, slightly longer than in the gas phase, are included in a matrix of db24c8 molecules. http://www.mdpi.com/2073-4352/1/4/215/ Wed, 28 Sep 2011 00:00:00 CEST Crystals 2011-09-28 1 4 Communication 215 219 2073-4352 Iodine Molecules Included in the Structure of Dibenzo-24-Crown-8, (I2)@(db24c8) 2011-09-28 doi: 10.3390/cryst1040215 Christine Walbaum Ingo Pantenburg Gerd Meyer http://www.mdpi.com/2073-4352/1/3/206/ Synthesis and single-crystal X-ray structure determination of the new antimonide oxide, Ba5Cd2Sb4O2 are reported. Ba5Cd2Sb4O2 crystallizes in the monoclinic space group C2/m (No. 12) with unit cell parameters: a = 17.247(7) Å, b = 4.9279(18) Å, c = 12.240(5) Å, and β = 132.558(4)°; Z = 2. Its crystal structure can be described as a polyanionic [Cd2Sb4]6– sub-lattice made up of fused CdSb4 tetrahedra, stacked between puckered slabs of oxo-anions, O2–, and Ba2+ cations. This structure can also be described as a “double-salt”, i.e., a structure composed of fragments from the Zintl phase Ba3Cd2Sb4 intercalated by two BaO-like moieties. The topological similarities between the structures of these compounds are discussed. http://www.mdpi.com/2073-4352/1/3/206/ Tue, 20 Sep 2011 00:00:00 CEST Crystals 2011-09-20 1 3 Article 206 214 2073-4352 Ba5Cd2Sb4O2—A New Antimonide Oxide with a Complex Structure 2011-09-20 doi: 10.3390/cryst1030206 Gregory M. Darone Svilen Bobev http://www.mdpi.com/2073-4352/1/3/195/ Recently we showed how crystallization in microemulsions could lead directly to the most stable polymorph, thereby leapfrogging Ostwald’s rule of stages. Here we consider in more details the crystallization of mefenamic acid from dimethylformamide microemulsions. Crystallization of mefenamic acid from bulk DMF has previously been shown to produce only the metastable Form II irrespective of the supersaturation or temperature. In contrast, we show that stable Form I can be produced from DMF microemulsions provided the lowest supersaturations that can achieve crystallization are used; these correspond to initial supersaturations that are significantly higher than those commonly used in bulk solution crystallizations, owing to the large decrease in supersaturation that occurs when a nuclei grows in a 3D-nanoconfined droplet. Increasing the supersaturation above the minimum required for crystallization leads to increasing proportions of metastable Form II crystals. In compositions crystallizing a mixture of Form I and Form II crystals, the Form I crystals can nevertheless be obtained exclusively by slowly heating the microemulsions. http://www.mdpi.com/2073-4352/1/3/195/ Mon, 19 Sep 2011 00:00:00 CEST Crystals 2011-09-19 1 3 Article 195 205 2073-4352 Crystallization of Mefenamic Acid from Dimethylformamide Microemulsions: Obtaining Thermodynamic Control through 3D Nanoconfinement 2011-09-19 doi: 10.3390/cryst1030195 Catherine E. Nicholson Sharon J. Cooper http://www.mdpi.com/2073-4352/1/3/178/ Despite the simple chemical formula, [Ni(1,10-phenanthroline)2(H2O)2](NO3)2, crystallizes with a remarkably complicated 3-D hydrogen bonding supramolecular assembly. The title compound crystallizes in the monoclinic space group P21/c, with an unusually long b axis and a large cell volume. A huge asymmetric unit has been identified, containing six discrete [Ni(1,10-phen)2(H2O)2]2+ cations and twelve nitrate anions. Detailed analyses of the crystal structure and O-H×××O and C-H×××O hydrogen bonding interactions are reported and discussed. In this way the anion-directed assembly of the 3-D structure is illustrated. The thermal and spectroscopic properties of the compound are described. Upon heating to 308 K, the crystal undergoes a phase change to a much simpler structure with a single [Ni(1,10-phen)2(H2O)2]2+ cation within the asymmetric unit and unit cell volume one sixth of that at low temperature. Although the crystal decomposed during data collection, it was possible to establish the molecular packing in the high temperature form and relate it to that at low temperature. http://www.mdpi.com/2073-4352/1/3/178/ Thu, 08 Sep 2011 00:00:00 CEST Crystals 2011-09-08 1 3 Article 178 194 2073-4352 [Ni(1,10-phenanthroline)2(H2O)2](NO3)2: A Simple Coordination Complex with a Remarkably Complicated Structure that Simplifies on Heating 2011-09-08 doi: 10.3390/cryst1030178 Timothy J. Prior Apinpus Rujiwatra Yothin Chimupala http://www.mdpi.com/2073-4352/1/3/171/ Synthesis of the title compound from 4-methoxyaniline was accomplished in three steps. The structure was supported by spectroscopic data and unambiguously confirmed by single crystal X-ray diffraction data. It crystallizes in the monoclinic space group P21 with unit cell dimensions α = 9.9349(8), b = 6.3377(5), c = 10.5783(10) Å, β = 97.752(3)°, V = 659.97(10) Å3, Z = 2. http://www.mdpi.com/2073-4352/1/3/171/ Mon, 29 Aug 2011 00:00:00 CEST Crystals 2011-08-29 1 3 Communication 171 177 2073-4352 Synthesis and Crystal Structure of 3-(4-Methoxyphenyl)-2-thioxo-2,3-dihydroquinazolin-4(1H)-one 2011-08-29 doi: 10.3390/cryst1030171 Aamer Saeed Shams ul Mahmood H. Ishida http://www.mdpi.com/2073-4352/1/3/163/ Large crystals of the methyl ester of the N-a-benzyloxycarbonyl protected Ala-Phe dipeptide (Z-AF-OMe) were obtained after the very slow evaporation of a solution of the corresponding carboxylic acid (Z-AF-OH) in methanol containing an excess of HCl. The structure was confirmed by single crystal X-ray diffraction data. It crystallizes in the orthorhombic space group P212121 with unit cell dimensions a = 5.0655(6) Å, b = 8.4614(8) Å, c = 46.856(5) Å, V = 2008.3(4) Å3, Z = 4. In the crystal, the molecules form hydrogen bonded chains running along the a axis of the unit cell. Other secondary interactions are also discussed. http://www.mdpi.com/2073-4352/1/3/163/ Mon, 22 Aug 2011 00:00:00 CEST Crystals 2011-08-22 1 3 Article 163 170 2073-4352 Crystal Structure of the N-Benzyloxycarbonyl-alanyl-phenylalanyl-methyl Ester: The Importance of the H-Bonding Pattern 2011-08-22 doi: 10.3390/cryst1030163 Ignacio Alfonso Michael Bolte M. Isabel Burguete Santiago V. Luis http://www.mdpi.com/2073-4352/1/3/145/ Systematic syntheses in the Ba–Ga–Sn system confirmed the existence of a new ternary phase BaGa1.79Sn4.21(2) (EuGa2Ge4 structure type; orthorhombic space group Cmcm, Pearson symbol oS28) with lattice parameters a = 4.5383(6) Å, b = 12.2486(16) Å, c = 14.3747(19) Å. The structure is best viewed as an open-framework based on tetrahedrally coordinated Sn/Ga atoms with Ba atoms enclosed in the voids within it. The new phase co-precipitates with two other compounds with very similar compositions—Ba8Ga14.5Sn31.5(4) (K4Si23 structure type; cubic space group , Pearson symbol cP54; a = 11.6800(12) Å), and Ba8Ga13.2Sn32.8(3), (Eu4Ga8Ge15 structure type; cubic space group , Pearson symbol cI54; a = 11.5843(7) Å). Detailed discussion on how syntheses affect the crystal chemistry, and the temperature dependence of the atomic displacement parameters, obtained from single-crystal structure refinements, are also reported in this article. http://www.mdpi.com/2073-4352/1/3/145/ Wed, 17 Aug 2011 00:00:00 CEST Crystals 2011-08-17 1 3 Article 145 162 2073-4352 Ternary Compounds in the Sn-Rich Section of the Ba–Ga–Sn System: Ba8Ga16–xSn30+x (1.1 ≤ x ≤ 2.8) Clathrates of Type-I and Type-VIII, and BaGa2–xSn4+x (x ≈ 0.2) with a Clathrate-like Structure 2011-08-17 doi: 10.3390/cryst1030145 Marion C. Schäfer Yuki Yamasaki Veronika Fritsch Svilen Bobev http://www.mdpi.com/2073-4352/1/3/136/ When crystallized from ethanol, 7,7-dimethyl-2-pyridin-4-yl-6,7-dihydro-1,2,4-triazolo[1,5-a][1,3,5]triazin-5-amine forms crystals which have monoclinic (P21/n) symmetry with unit cell dimensions a = 7.3326(5) Å, b = 19.4897(14) Å, c = 8.6586(6) Å, α = 90°, β = 106.069(2)°, γ = 90°, V = 1189.06(14) Å3, Z = 4. The triazine ring in the molecule has a flattened boat conformation with gem-dimethyl groups as flagpole and bowsprit at the bow. The puckering parameters for the ring are: Q = 0.2996(14) Å, θ = 111.7(3)° and φ = 124.1(3)°. In the crystal, molecules are arranged in the three types of chains generated by the intermolecular NH···N hydrogen bonds. The extended chains with the C(11) graph-set motif running along a [010] axis are formed by the amino group hydrogen atom and the pyridine nitrogen atom of another molecule. The C(4)C(6) chains with the R22(8) binary graph-set motif running along a [101] direction are formed by linking the amino group hydrogen atom and the hydrogen atom at the triazine nitrogen atom with the triazole and triazine nitrogen atoms of another molecule, respectively. The centrosymmetric inverted dimers are formed via the C-H···π interactions between the methyl group hydrogen and the pyridine ring of the pair molecule. http://www.mdpi.com/2073-4352/1/3/136/ Thu, 11 Aug 2011 00:00:00 CEST Crystals 2011-08-11 1 3 Article 136 144 2073-4352 Molecular and Crystal Structure of 7,7-Dimethyl-2-pyridin-4-yl-6,7-dihydro-1,2,4-triazolo[1,5-a][1,3,5]triazin-5-amine [1] 2011-08-11 doi: 10.3390/cryst1030136 Anton V. Dolzhenko Geok Kheng Tan Lip Lin Koh Anna V. Dolzhenko Wai Keung Chui http://www.mdpi.com/2073-4352/1/3/128/ In China, Korea, and Japan, Umbilicaria esculenta is considered as both food and medicinal resources from lichen. In the current study, a prismatic crystal was first isolated from edible lichen U. esculenta via solvent fractionation. The structure of the crystalline compound was elucidated as allantoin using single-crystal X-ray crystallographic and spectroscopic techniques. In light of the wide use of synthesized allantoin in cosmetic industry as a skin protectant, the biological origin of the allantoin isolated from natural food stuff edible lichen has great potential to be developed into functional cosmetics. Current findings also provided useful information for ecologists to further explore the role of lichen and allantoin in nitrogen metabolism. http://www.mdpi.com/2073-4352/1/3/128/ Tue, 09 Aug 2011 00:00:00 CEST Crystals 2011-08-09 1 3 Article 128 135 2073-4352 Crystal Structure Characterization of Natural Allantoin from Edible Lichen Umbilicaria esculenta 2011-08-09 doi: 10.3390/cryst1030128 Baojun Xu Changkeun Sung Byunghee Han http://www.mdpi.com/2073-4352/1/3/120/ An unsymmetrical trinickel metal complex, [Ni3(dpa)4(4-sb)(H2O)]×3H2O (1), where dpa is a 2,2’-dipyridylamine anion and 4-sb is 4-sulfobenzoate dianion, was synthesized and characterized by X-ray crystallography, IR, elemental analysis, fluorescence, and cyclic voltammetry. The molecular structure of 1 is a cluster with a linear trimer. The extended structure is a 3D architecture assembled by hydrogen bonds. The 4-sulfobenzoate axial replacement leads to the change of Ni-Ni distances, the shift of the fluorescence emission, and the reversible one-electron reduction process without oxidation process. http://www.mdpi.com/2073-4352/1/3/120/ Fri, 05 Aug 2011 00:00:00 CEST Crystals 2011-08-05 1 3 Article 120 127 2073-4352 An Unsymmetrical Trinickel Metal Complex with 4-Sulfobenzoate Axial Ligand: [Ni3(dpa)4(4-sb)(H2O)]×3H2O 2011-08-05 doi: 10.3390/cryst1030120 Xiao-Feng Zheng Long-Guan Zhu http://www.mdpi.com/2073-4352/1/3/112/ The phase and texture of a newly developed solution-processed copper phthalocyanine (CuPc) thin film have been investigated by two-dimensional grazing incidence X-ray diffraction. The results show that it has β phase crystalline structure, with crystallinity greater than 80%. The average size of the crystallites is found to be about 24 nm. There are two different arrangements of crystallites, with one dominating the diffraction pattern. Both of them have preferred orientation along the thin film normal. Based on the similarities to the vacuum deposited CuPc thin films, the new solution processing method is verified to offer a good alternative to vacuum process, for the fabrication of low cost small molecule based organic photovoltaics. http://www.mdpi.com/2073-4352/1/3/112/ Fri, 29 Jul 2011 00:00:00 CEST Crystals 2011-07-29 1 3 Article 112 119 2073-4352 Phase and Texture of Solution-Processed Copper Phthalocyanine Thin Films Investigated by Two-Dimensional Grazing Incidence X-Ray Diffraction 2011-07-29 doi: 10.3390/cryst1030112 Lulu Deng Kewei Wang Cindy X. Zhao Han Yan James F. Britten Gu Xu http://www.mdpi.com/2073-4352/1/3/104/ Investigations of the system Ba–In–Sn, with the objective to synthesize Ba8In16Sn30 clathrate using Sn and In flux reactions, yielded instead the known BaSn3 compound (P63/mmc; a = 7.228(2) Å, c = 5.469(3) Å) from Sn flux and its In-doped variant BaSn2.8In0.2(1) (a = 7.260(1) Å, c = 5.382(2) Å) from In flux. BaSn3–xInx is the first, and up until now, the only ternary phase containing these elements. Its structure is isomorphic with the Ni3Sn type (Pearson symbol hP8) and is apparently capable of sustaining small variations in the valence electron count by virtue of replacing Sn with the electron poorer In. Electrical resistivity measurements on single-crystals of both undoped and doped phases show different metallic-like behavior, suggesting that neither BaSn3 nor BaSn3–xInx are valence compounds. http://www.mdpi.com/2073-4352/1/3/104/ Tue, 12 Jul 2011 00:00:00 CEST Crystals 2011-07-12 1 3 Article 104 111 2073-4352 Indium Doping in BaSn3–x Inx (0 ≤ x ≤ 0.2) with Ni3Sn Structure 2011-07-12 doi: 10.3390/cryst1030104 Marion C. Schäfer Yuki Yamasaki Veronika Fritsch Svilen Bobev http://www.mdpi.com/2073-4352/1/3/99/ The ternary chloride Na3MoCl6 is obtained as red crystals from a disproportionation reaction of molybdenum dichloride, {Mo6}Cl12, in an acidic NaCl/AlCl3 melt at 350 °C. The crystal structure (trigonal, P-31c, a = 687.1(1), c = 1225.3(2) pm, Z = 2, V = 501,0(1) 106 pm3) is that of Na3CrCl6: within a hexagonal closest-packing of chloride ions two thirds of the octahedral voids are filled between the AB double layers with Na+/Mo3+, and between the BA layers with Na+. http://www.mdpi.com/2073-4352/1/3/99/ Mon, 04 Jul 2011 00:00:00 CEST Crystals 2011-07-04 1 3 Short Note 99 103 2073-4352 Crystal Structure of Na3MoCl6 2011-07-04 doi: 10.3390/cryst1030099 Martin Beran Gerd Meyer http://www.mdpi.com/2073-4352/1/3/87/ Three new cluster compounds, Cs2NaAs7, Cs4ZnAs14, and Cs4CdAs14 were obtained from high temperature reactions. Their structures feature heptaarsenide [As7]3– anions, where the clusters in Cs4ZnAs14 and Cs4CdAs14 are dimerized by the linkers Zn and Cd, respectively. The bonding characteristics of these clusters are discussed and compared. Band structure calculation on Cs2NaAs7 suggests that this compound is a semiconductor with an energy gap of circa 1.6 eV, which is in consistent with the dark red color of the crystals. http://www.mdpi.com/2073-4352/1/3/87/ Tue, 28 Jun 2011 00:00:00 CEST Crystals 2011-06-28 1 3 Article 87 98 2073-4352 New Compounds with [As7]3– Clusters: Synthesis and Crystal Structures of the Zintl Phases Cs2NaAs7, Cs4ZnAs14 and Cs4CdAs14 2011-06-28 doi: 10.3390/cryst1030087 Hua He Chauntae Tyson Svilen Bobev http://www.mdpi.com/2073-4352/1/3/78/ Single crystals of ternary chalcogenides with the composition BaLu2Ch4 (Ch = S, Se and Te; orthorhombic, Pnma; a = 1211.4–1353.6, b = 395.6–438.5, c = 1427.8–1593.6 pm) could be obtained after attempts to synthesize ternary lutetium(III) nitride chalcogenides using the elements (Lu and Ch) along with BaN3Cl as a nitrogen source. Their crystal structures are isotypic with CaFe2O4 containing two sorts of {[LuChCh]8–} chains built up of edge-linked [(Lu1)(Ch2)(Ch3)3(Ch4)2]9– and [(Lu2)(Ch1)3(Ch2)2(Ch4)]9– octahedra, respectively. A further interconnection via the chalcogenide anions (Ch3)2– and (Ch1)2– leads to double chains, where either (Lu1)3+ or (Lu2)3+ coordinates these chalcogenide anions as well. The three-dimensional framework {[Lu2Ch4]2–} emerges from the corner-linkage of the two kinds of double chains forming large channels apt to take up the Ba2+ cations. These divalent cations exhibit eight contacts to chalcogenide anions resulting in the formation of bicapped trigonal prisms [BaCh8]14–. http://www.mdpi.com/2073-4352/1/3/78/ Mon, 27 Jun 2011 00:00:00 CEST Crystals 2011-06-27 1 3 Article 78 86 2073-4352 Single Crystals of the Isotypic Series BaLu2Ch4 (Ch = S, Se and Te) with CaFe2O4-Type Structure 2011-06-27 doi: 10.3390/cryst1030078 Christian M. Schurz Thomas Schleid http://www.mdpi.com/2073-4352/1/2/69/ The syntheses and crystal structures of benzenesulfonylamino-3-(4-benzenesulfonyloxy-phenyl)-propionic acid (1) and 2-(toluene-4-sulfonylamino)-3-[4-(toluene-4-sulponyloxy)-phenyl]-propionic acid (2) are described. The L-tyrosine cores of the molecules show significant conformational differences. In 1, both organic molecules show intramolecular aromatic π–π stacking and in 2 a very short intermolecular Cα–H···O interaction is seen. The structures of 1 and 2 are compared with those of related materials. Crystal data: 12·H2O·MeOH [2(C21H19NO7S2)·H2O·CH4O], Mr = 973.04, monoclinic, P21 (No. 4), a = 8.0078 (4) Å, b = 34.0704 (16) Å, c = 8.5506 (3) Å, β = 94.239 (3)°, V = 2326.47 (18) Å3, Z = 2, T = 296 K, R(F) = 0.062, wR(F2) = 0.157, 2·H2O (C23H25NO7S2·H2O), Mr = 507.56, monoclinic, P21 (No. 4), a = 5.7171 (7) Å, b = 24.359 (3) Å, c = 9.1043 (10) Å, β = 104.563 (6)°, V = 1227.2 (2) Å3, Z = 2, T = 296 K, R(F) = 0.055, wR(F2) = 0.092. http://www.mdpi.com/2073-4352/1/2/69/ Tue, 14 Jun 2011 00:00:00 CEST Crystals 2011-06-14 1 2 Article 69 77 2073-4352 Structures of Benzenesulfonylamino-3-(4-benzenesulfonyloxy-phenyl)-propionic acid and 2-(toluene-4-sulfonylamino)-3-[4-(toluene-4-sulponyl-oxy)-phenyl]-propionic acid: Variations in L-tyrosine Backbone Conformation, Intramolecular Aromatic π–π Stacking and Short C–H···O Interactions 2011-06-14 doi: 10.3390/cryst1020069 Muneeb Hayat Khan Islam Ullah Khan Muhammad Nadeem Arshad H. M. Rafique William T. A. Harrison http://www.mdpi.com/2073-4352/1/2/59/ The syntheses and single-crystal structures of Ba2(C2O4)(H2PO3)2 (1) and C2H10N2·Ba(H2O)2(HC2O4)4 (2) are described. Compound 1 is a three-dimensional mixed-anion framework containing BaO9 coordination polyhedra, which approximate to monocapped square anti-prisms: the connectivity of the BaO9 units via edges and triangular faces leads to a sheet structure. The oxalate ion in 1 is substantially twisted about its C–C bond [dihedral angle between the CO2 groups = 33.8 (3)°]. Compound 2 is a molecular salt containing ethylenediammonium dications and [Ba(HC2O4)4(H2O)2]2– dianions, which are linked by O–HLO and N–HLO hydrogen bonds. The BaO10 coordination polyhedron can be described as a distorted pentagonal anti-prism. Crystal data: 1 (C2H4Ba2O10P2), Mr = 524.68, monoclinic, C2/c (No. 15), Z = 4, a = 12.3829 (3) Å, b = 7.9124 (2) Å, c = 11.0858 (3) Å, b = 114.788 (2)°, V = 986.10 (4) Å3, R(F) = 0.016, wR(F2) = 0.040. 2 (C10H18BaN2O10), Mr = 591.60, monoclinic, C2/m (No. 12), Z = 2, a = 12.7393 (7) Å, b = 13.0111 (7) Å, c = 5.6050 (3) Å, b = 104.208 (4)°, V = 900.62 (8) Å3, R(F) = 0.027, wR(F2) = 0.054. http://www.mdpi.com/2073-4352/1/2/59/ Wed, 08 Jun 2011 00:00:00 CEST Crystals 2011-06-08 1 2 Article 59 68 2073-4352 Barium Oxalates Combined with Oxo-Anions and Organic Cations: Syntheses and Structures of Ba2(C2O4)(H2PO3)2 and C2H10N2·Ba(H2O)2(HC2O4)4 2011-06-08 doi: 10.3390/cryst1020059 Samuel J. Iveson Chloe B. Johnston William T.A. Harrison http://www.mdpi.com/2073-4352/1/2/47/ The syntheses and single-crystal structures of Mo(CO)3(phen)(dipy) (1), Mo(CO)3(biquin)(dipy) (2) and Mo(CO)3(dpme)(dipy) (3), (phen = 1,10-phenanthroline, C12H8N2; dipy = 2,2'-dipyridylamine, C10H9N3; biquin = 2,2'-biquinoline, C18H12N2; dpme = 2,2'-dipyridylmethane, C11H10N2) are described. In each case, distorted fac-MoC3N3 octahedral coordination geometries arise for the metal atoms. Short intramolecular N–H…C interactions from the dipy N–H group to a carbonyl carbon atom occur in each structure. Crystal data: 1 (C25H17MoN5O3), Mr = 531.38, monoclinic, P21/n (No. 14), Z = 4, a = 11.0965 (5) Å, b = 13.0586 (6) Å, c = 16.6138 (8) Å, b = 108.324 (1)°, V = 2285.31 (18) Å3, R(F) = 0.035, wR(F2) = 0.070. 2 (C31H21MoN5O3), Mr = 607.47, monoclinic, P21/n (No. 14), Z = 4, a = 11.4788 (6) Å, b = 19.073 (1) Å, c = 11.9881 (6) Å, b = 95.179 (1)°, V = 2613.9 (2) Å3, R(F) = 0.030, wR(F2) = 0.076. 3 (C24H19MoN5O3), Mr = 521.38, monoclinic, P21/n (No. 14), Z = 4, a = 8.4222 (3) Å, b = 21.5966 (9) Å, c = 12.5011 (5) Å, b = 94.065 (1)°, V = 2268.12 (15) Å3, R(F) = 0.025, wR(F2) = 0.065. http://www.mdpi.com/2073-4352/1/2/47/ Wed, 08 Jun 2011 00:00:00 CEST Crystals 2011-06-08 1 2 Article 47 58 2073-4352 Short Intramolecular N–H⋯C(carbonyl) Interactions in Mixed-Ligand Molybdenum Hexacarbonyl Derivatives 2011-06-08 doi: 10.3390/cryst1020047 Matthew G. Budge Kathleen J. Muir Geoffrey P. McQuillan William T.A. Harrison http://www.mdpi.com/2073-4352/1/2/40/ The reduction of hafnium tetraiodide, HfI4, with aluminum at 600 °C or 850 °C in the presence of a NaI flux resulted in black single crystals of Hf0.86(1)I3. This composition corresponds well to the upper end of the non-stoichiometry range 0.89 ≤ x ≤ 1.00 previously reported for HfxI3. The crystal structure (a = 1250.3(2), c = 1999.6(3) pm, R-3m, Z = 18) is made up of hexagonal closest packed layers of iodide ions. One third of the octahedral holes would be filled as in TiI3 or ZrI3 if it were Hf1.00I3. In Hf0.86(1)I3, one out of six octahedral holes along [001] are, however, only occupied by 16%. In contrast to TiI3-I and ZrI3, one striking structural feature is in the formation of linear hafnium trimers with identical Hf―Hf distances of 318.3(2) pm rather than the formation of dimers. These may be associated with Hf―Hf bonding although only 2.64 electrons are available for one Hf5.16I18 column. http://www.mdpi.com/2073-4352/1/2/40/ Tue, 10 May 2011 00:00:00 CEST Crystals 2011-05-10 1 2 Article 40 46 2073-4352 Linear Trimeric Hafnium Clusters in Hf0.86(1)I3 2011-05-10 doi: 10.3390/cryst1020040 Jan Beekhuizen Anja-Verena Mudring Gerd Meyer http://www.mdpi.com/2073-4352/1/2/34/ The title thiourea was synthesized by reaction of 3,4,5-trimethoxybenzoyl isothiocyante with 3-fluoroaniline. The 3,4,5-trimethoxybenzoyl isothiocyante was produced in situ by reaction of 3,4,5-trimethoxybenzoyl chloride with ammonium thiocyanate in dry acetonitrile. The structure was confirmed by the spectroscopic, elemental analysis and single crystal X-ray diffraction data. It crystallizes in the monoclinic space group P21/c with unit cell dimensions a = 13.0966(9), b = 16.6460(13), c = 7.8448(5), β = 106.721(5)°, V 1637.9(2) ų, Z = 4. http://www.mdpi.com/2073-4352/1/2/34/ Mon, 09 May 2011 00:00:00 CEST Crystals 2011-05-09 1 2 Communication 34 39 2073-4352 Synthesis and Crystal Structure of 1-(3-fluorophenyl)-3-(3,4,5-trimethoxybenzoyl)thiourea 2011-05-09 doi: 10.3390/cryst1020034 Aamer Saeed Uzma Shaheen Michael Bolte http://www.mdpi.com/2073-4352/1/2/28/ A carbazole-triazine hybrid was prepared by addition-elimination between carbazole and 2,4,6-trichlorotriazine in the presence of base. The compound shows intensely blue fluorescence both in solution and solid state when irradiated with UV-radiation. The structure of (3) was supported by the spectroscopic data and unambiguously confirmed by the single crystal X-ray diffraction data. It was crystallized in the monoclinic space group C2/c with unit cell dimensions a = 20.280(3), b = 8.0726(14), c = 16.005(3) Å, α = γ = 90°, β = 98.947(3)°, V = 2588.3(8) ų, Z = 8. http://www.mdpi.com/2073-4352/1/2/28/ Tue, 26 Apr 2011 00:00:00 CEST Crystals 2011-04-26 1 2 Communication 28 33 2073-4352 Synthesis and Crystal Structure of 9-(4,6-dichloro-1,3,5-triazin-2-yl)-9H-carbazole 2011-04-26 doi: 10.3390/cryst1020028 Aamer Saeed Madiha Kazmi Shahid Ameen Samra Ulrich Flörke http://www.mdpi.com/2073-4352/1/2/22/ A new open-framework iron borophosphate, KFe[BP2O8(OH)], has been obtained by ionothermal synthesis from KH2PO4, FeCl3∙4H2O, H3BO3 and [C4mpyr]Br (1-butyl-1-methylpyrrolidinium bromide). Single-crystal X-ray diffraction analysis shows that KFe[BP2O8(OH)] (monoclinic, P21/c, a = 9.372(2) Å , b = 8.146(2)Å , c = 9.587(2) Å, β = 101.18(3)°, V = 718.0(2)Å3 and Z = 4) has a three-dimensional (3-D) framework structure composed by {Fe(III)O5(OH)} octahedra as well as {BO3(OH)} and {PO4} tetrahedra. As anionic structural sub-unit, KFe[BP2O8(OH)], contains an infinite open-branched {[BP2O8(OH)]4-} chain which is formed by alternating {BO3(OH)} and {PO4} tetrahedra. {Fe(III)O5(OH)} octahedra share common O corners with five phosphate tetrahedra and the OH corner links to the hydrogen borate group to give a 3D framework. The negative charges of the inorganic framework are balanced by K+ ions. http://www.mdpi.com/2073-4352/1/2/22/ Tue, 19 Apr 2011 00:00:00 CEST Crystals 2011-04-19 1 2 Article 22 27 2073-4352 A New Open-framework Iron Borophosphate from Ionic Liquids: KFe[BP2O8(OH)] 2011-04-19 doi: 10.3390/cryst1020022 Guangmei Wang Anja-Verena Mudring http://www.mdpi.com/2073-4352/1/1/15/ The first ternary lanthanide telluride-bromide La3Te4Br was obtained from a mixture of LaTe and LaBr3 (in the presence of iridium) in a sealed tantalum container at elevated temperatures. The crystal structure (orthorhombic, Pnma, a = 1634.3(2), b = 435.0(1), c = 1426.6(2) pm, Z = 4, R1 (I0 > 2s(I0)) = 0.0349) is built from dicapped trigonal prisms of tellurium and bromine atoms surrounding lanthanum in two different ways. The dicapped trigonal prisms are connected via common edges to a threedimensional structure, in the same fashion as is known for the binary U3Te5. La3Te4Br is a valence compound according to (La3+)3(Te2-)4(Br-) and one out of three lanthanide telluride-halides known to date. http://www.mdpi.com/2073-4352/1/1/15/ Mon, 21 Mar 2011 00:00:00 CET Crystals 2011-03-21 1 1 Article 15 21 2073-4352 The First Lanthanide Telluride-Bromide: La3Te4Br, a Valence Compound 2011-03-21 doi: 10.3390/cryst1010015 Markus Larres Anja-Verena Mudring Gerd Meyer http://www.mdpi.com/2073-4352/1/1/3/ KNaNbOF5 and KNaMO2F4 (M = Mo6+, W6+), three new layered oxide-fluoride perovskites with the general formula ABB’X6, form from the combination of a second-order Jahn-Teller d0 transition metal and an alkali metal (Na+) on the B-site. Alternating layers of cation vacancies and K+ cations on the A-site complete the structure. The K+ cations are found in the A-site layer where the fluoride ions are located. The A-site is vacant in the adjacent A-site layer where the axial oxides are located. This unusual layered arrangement of unoccupied A-sites and under bonded oxygen has not been observed previously although many perovskite-related structures are known. http://www.mdpi.com/2073-4352/1/1/3/ Fri, 18 Mar 2011 00:00:00 CET Crystals 2011-03-18 1 1 Article 3 14 2073-4352 New Layered Oxide-Fluoride Perovskites: KNaNbOF5 and KNaMO2F4 (M = Mo6+, W6+) 2011-03-18 doi: 10.3390/cryst1010003 Rachelle Ann F. Pinlac Charlotte L. Stern Kenneth R. Poeppelmeier http://www.mdpi.com/2073-4352/1/1/1/ The majority of the earth’s crust is made up of crystalline material. The research areas of mineralogy, petrology, chimie minerále (inorganic chemistry) and, of course, crystallography outgrew from the fascination of mankind with the color and symmetry of crystals. Crystals have translational symmetry in two or three dimensions, quasicrystals have translational symmetry in higher spaces. Further symmetries may be observed by the eye, by microscopic techniques or by the diffraction of X-ray, electron, or neutron beams. Diffraction techniques are also used, due to Max von Laue’s eminent discovery a century ago, to determine crystal structures. [...] http://www.mdpi.com/2073-4352/1/1/1/ Fri, 17 Dec 2010 00:00:00 CET Crystals 2010-12-17 1 1 Editorial 1 2 2073-4352 Welcome to Crystals: A New Open-Access, Multidisciplinary Forum for Growth, Structures and Properties of Crystals 2010-12-17 doi: 10.3390/cryst1010001 Gerd Meyer