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Crystals, Volume 1, Issue 3 (September 2011), Pages 78-214

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Open AccessArticle Single Crystals of the Isotypic Series BaLu2Ch4 (Ch = S, Se and Te) with CaFe2O4-Type Structure
Crystals 2011, 1(3), 78-86; doi:10.3390/cryst1030078
Received: 1 June 2011 / Revised: 14 June 2011 / Accepted: 21 June 2011 / Published: 27 June 2011
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Abstract
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 [...] Read more.
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–. Full article
Open AccessArticle New Compounds with [As7]3– Clusters: Synthesis and Crystal Structures of the Zintl Phases Cs2NaAs7, Cs4ZnAs14 and Cs4CdAs14
Crystals 2011, 1(3), 87-98; doi:10.3390/cryst1030087
Received: 27 May 2011 / Revised: 16 June 2011 / Accepted: 21 June 2011 / Published: 28 June 2011
Cited by 4 | PDF Full-text (434 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
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 [...] Read more.
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. Full article
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Open AccessArticle Indium Doping in BaSn3–x Inx (0 ≤ x ≤ 0.2) with Ni3Sn Structure
Crystals 2011, 1(3), 104-111; doi:10.3390/cryst1030104
Received: 20 June 2011 / Revised: 1 July 2011 / Accepted: 11 July 2011 / Published: 12 July 2011
Cited by 3 | PDF Full-text (269 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
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 [...] Read more.
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. Full article
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Open AccessArticle Phase and Texture of Solution-Processed Copper Phthalocyanine Thin Films Investigated by Two-Dimensional Grazing Incidence X-Ray Diffraction
Crystals 2011, 1(3), 112-119; doi:10.3390/cryst1030112
Received: 28 June 2011 / Revised: 26 July 2011 / Accepted: 28 July 2011 / Published: 29 July 2011
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Abstract
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 [...] Read more.
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. Full article
Open AccessArticle An Unsymmetrical Trinickel Metal Complex with 4-Sulfobenzoate Axial Ligand: [Ni3(dpa)4(4-sb)(H2O)]×3H2O
Crystals 2011, 1(3), 120-127; doi:10.3390/cryst1030120
Received: 15 April 2011 / Revised: 20 July 2011 / Accepted: 29 July 2011 / Published: 5 August 2011
Cited by 1 | PDF Full-text (395 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
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. [...] Read more.
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. Full article
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Open AccessArticle Crystal Structure Characterization of Natural Allantoin from Edible Lichen Umbilicaria esculenta
Crystals 2011, 1(3), 128-135; doi:10.3390/cryst1030128
Received: 7 July 2011 / Revised: 3 August 2011 / Accepted: 8 August 2011 / Published: 9 August 2011
Cited by 1 | PDF Full-text (591 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
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 [...] Read more.
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. Full article
Open AccessArticle 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]
Crystals 2011, 1(3), 136-144; doi:10.3390/cryst1030136
Received: 13 July 2011 / Revised: 10 August 2011 / Accepted: 11 August 2011 / Published: 11 August 2011
Cited by 1 | PDF Full-text (372 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
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 [...] Read more.
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. Full article
Open AccessArticle 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 BaGa2xSn4+x (x ≈ 0.2) with a Clathrate-like Structure
Crystals 2011, 1(3), 145-162; doi:10.3390/cryst1030145
Received: 18 July 2011 / Revised: 8 August 2011 / Accepted: 12 August 2011 / Published: 17 August 2011
Cited by 6 | PDF Full-text (2679 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
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 = [...] Read more.
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. Full article
Open AccessArticle Crystal Structure of the N-Benzyloxycarbonyl-alanyl-phenylalanyl-methyl Ester: The Importance of the H-Bonding Pattern
Crystals 2011, 1(3), 163-170; doi:10.3390/cryst1030163
Received: 15 July 2011 / Revised: 15 August 2011 / Accepted: 19 August 2011 / Published: 22 August 2011
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Abstract
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 [...] Read more.
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. Full article
Open AccessCommunication Synthesis and Crystal Structure of 3-(4-Methoxyphenyl)-2-thioxo-2,3-dihydroquinazolin-4(1H)-one
Crystals 2011, 1(3), 171-177; doi:10.3390/cryst1030171
Received: 13 July 2011 / Revised: 19 September 2011 / Accepted: 24 August 2011 / Published: 29 August 2011
Cited by 2 | PDF Full-text (508 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
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 [...] Read more.
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. Full article
Open AccessArticle [Ni(1,10-phenanthroline)2(H2O)2](NO3)2: A Simple Coordination Complex with a Remarkably Complicated Structure that Simplifies on Heating
Crystals 2011, 1(3), 178-194; doi:10.3390/cryst1030178
Received: 4 August 2011 / Revised: 31 August 2011 / Accepted: 7 September 2011 / Published: 8 September 2011
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Abstract
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 [...] Read more.
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. Full article
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Open AccessArticle Crystallization of Mefenamic Acid from Dimethylformamide Microemulsions: Obtaining Thermodynamic Control through 3D Nanoconfinement
Crystals 2011, 1(3), 195-205; doi:10.3390/cryst1030195
Received: 9 August 2011 / Revised: 8 September 2011 / Accepted: 15 September 2011 / Published: 19 September 2011
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Abstract
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 [...] Read more.
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. Full article
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Open AccessArticle Ba5Cd2Sb4O2—A New Antimonide Oxide with a Complex Structure
Crystals 2011, 1(3), 206-214; doi:10.3390/cryst1030206
Received: 18 August 2011 / Revised: 14 September 2011 / Accepted: 19 September 2011 / Published: 20 September 2011
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Abstract
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: [...] Read more.
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. Full article
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Open AccessShort Note Crystal Structure of Na3MoCl6
Crystals 2011, 1(3), 99-103; doi:10.3390/cryst1030099
Received: 10 May 2011 / Revised: 25 May 2011 / Accepted: 23 June 2011 / Published: 4 July 2011
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Abstract
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), [...] Read more.
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+. Full article
(This article belongs to the Special Issue Feature Paper)

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