Refinement of the crystal structure of Zn-containing greifensteinite

The crystal structure of Zn-containing greifensteinite from the Pirineus Mine (Minas Gerais, Brazil) was refined (R = 0.045, 562 reflections with |F| > 2σ(F)). The unit-cell parameters are a = 15.941(3) Å, b = 11.877(3) Å, c = 6.625(2) Å, β = 95.09(2)°; V = 1249.4 ų; sp. gr. C2/c; and Z = 2. The idealized formula is [Mn(Fe²⁺, Zn)₄]Ca₂Be₄(PO₄)₆(OH)₄ · 6H₂O. The mineral is isostructural with the previously studied monoclinic representatives of the roscherite group from different deposits and differs from these representatives in that it contains Zn in one of two octahedral positions.     

Crystal structure analysis of 4-phenylquinolin-2-(1<Emphasis Type="Italic">H</Emphasis>)-one

The crystal structure of 4-phenylquinolin-2-(1H)-one (C₁₅H₁₁NO) is determined by X-ray diffraction. The compound crystallizes in the orthorhombic crystal system (space group Pbca) with the unit cell parameters a = 7.382(2) Å, b = 21.795(3) Å, c = 14.066(5) Å, and Z = 8. The structure is solved by direct methods and refined to an R-value of 0.0398 for 1360 observed reflections [F₀ > 4σ (F₀)]. The quinoline moiety and the substituted phenyl ring are nearly planar. The dihedral angle between these two moieties is 64.65(6)°. The crystal structure is stabilized by two intermolecular N-H?O and C-H?O interactions.     

Strontium in the collinsite structure: Rietveld refinement

The crystal structure of a strontium variety of a rare phosphate—mineral collinsite (Ca_{2 ? x}Sr_x)₂Mg[PO₄] · 2H₂O was solved from powder X-ray diffraction data (λ CuK_α radiation, Ni filter, 12.36° ≤ 2θ ≤ 100.00°, scan step 0.02°, exposure time per step 15 s) by the Rietveld method (R_wp = 4.15%, R_F = 1.03%, R_B = 2.46%); a = 5.8219(1) Å, b = 6.8319(2) Å, c = 5.4713(1) Å, α = 96.965(2)°, β = 108.846(2)°, γ = 107.211(2)°, sp. gr., \(\bar P1\), Z = 1, ρ_calcd = 3.12 g/cm³ (at x = 0.72). The new mineral was discovered in carbonatites from the Kovdor alkaline-ultrabasic massif. The crystallochemical data for collinsite were analyzed and compared with those for isotypic minerals of the fairfieldite group. Characteristic features of the low-temperature geochemistry of strontium were established.     

Refined crystal structure of parakeldyshite and the genetic crystal chemistry of zirconium minerals with [Si<Subscript>2</Subscript>O<Subscript>7</Subscript>] diorthogroups

The structure of the mineral parakeldyshite Na_1.93ZrSi₂O_6.93(OH)_0.07 is refined by X-ray diffraction analysis. The main crystallographic data are as follows: space group P \(\overline 1 \), a = 6.617(2) Å, b = 8.813(1) Å, c = 5.426(1) Å, α = 87.26(3)°, β = 85.68(3)°, γ = 71.45(3)°, and R _F = 0.0153. The initial structural model of this mineral is confirmed. Within this model, the structure of parakeldyshite is based on the heteropolyhedral framework formed by [Si₂O₇] diorthogroups, which are linked together through isolated zirconium octahedra. The fundamental difference between the structure under investigation and the initial structural model is associated with the arrangement of the extraframework cations. A comparative crystal chemical analysis of the zirconium silicates with [Si₂O₇] diorthogroups is performed.     

Refined structure of afwillite from the northern Baikal region

The crystal structure of the mineral afwillite [Ca₁₂(H₂O)₈][SiO₄]₄[SiO₂(OH)₂]₄ from the northern Baikal region was refined in a triclinic unit cell with the following parameters: a = 16.330(2) Å, b = 5.6389(6) Å, c = 11.685(1) Å, α = 90.08(1)°, β = 126.446(2)°, γ = 89.95(1)°, and sp. gr. P1. The triclinic unit cell is related to the monoclinic unit cell determined earlier (sp. gr. Cc, a = 16.278(1) Å, b = 5.6321(4) Å, c = 13.236(1) Å, and β = 134.898(3)°) by the transformation matrix [?100/010/101]. The structural model was determined using the phase-correction procedure and refined anisotropically to R = 2.8% based on 3270 independent reflections with F > 3σ(F). The crystal-chemical formula of afwillite was revised. The characteristic features of the IR spectrum of afwillite were explained based on the structural data.     

Catenated molecular pattern in the crystal structure of a copper(II) complex with pyrazine-2,6-dicarboxylic acid and chloride ligands

The crystals of catena-dichloro-(dihydrogen pyrazine-2,6-dicarboxylato-O,O′,N,-N′) copper(II) dihydrate Cu[H₂(2,6-PZDC)]Cl₂?2H₂O are monclinic, space group C2/c with a = 11.658(2) Å, b = 6.778(1) Å, c = 16.390(3) Å, β = 98.90(3)^°, and Z = 4. Two adjacent copper(II) ions are bridged by a fully protonated pyrazine-2,6-dicarboxylic acid molecule which uses for bridging its O,O′,N-bonding moiety on one side and a single hetero-ring nitrogen atom on the other. Two chloride ions in axial position complete the octahedral coordination around the metal ions with bond distances: Cu–N 2.027(3) ÅA, Cu–N′ 2.005(3) ÅA, Cu–Cl. 2.281(1) ÅA, and Cu–O 2.446(2) ÅA. Copper(II) ions are located in the center of symmetry and are coplanar with the ligand acid molecule forming flat molecular chains propagating in the direction of the b axis. Hydrogen bonds via solvation water molecule link the chains into molecular layers parallel to the ac plane. Weak van der Waals type interactions operate between the layers.     

Synthesis and Crystal Structure of a Four-coordinated Cobalt Complex with 1-Methylbenzimidazole

A four-coordinated complex, L₂Co(NCO)₂, (L = 1-methylbenzimidazole) has been synthesized and characterized by IR spectroscopy, elemental analyses, and single crystal X-ray diffraction. The crystal is monoclinic, a = 14.522(2) Å, b = 14.610(2) Å, c = 8.6850(13) Å, β = 92.037(3)°, Z = 4, sp. gr. P2₁/c. Bond lengths Co–N(L) are equal to 2.0165(16) and 2.0174(15) Å, Co–O(NCO) are 1.944(2) and 1.945(2) Å. Intermolecular C–H···O, C–H···N, and C–H···π interactions link the molecules into three-dimensional networks in the crystal.     

Growth and crystal structure of binary molybdate CsFe(MoO<Subscript>4</Subscript>)<Subscript>2</Subscript>

CsFe(MoO₄)₂ single crystals have been grown by solution-melt crystallization with a charge-to-solvent ratio of 1: 3 (with Cs₂Mo₃O₁₀ used as a solvent). The crystal structure of this compound has been refined by X-ray diffraction (X8 APEX automatic diffractometer, MoK _α radiation, 356 F(hkl), R = 0.0178). The trigonal unit cell has the following parameters: a = b = 5.6051(2) Å, c = 8.0118(4) Å, V = 217.985(15) ų, Z = 1, ρ_calc = 3.875 g/cm³, and sp. gr. P \(\bar 3\) m1. The structure is composed of alternating layers of FeO₆ octahedra (with MoO₄ tetrahedra attached by sharing vertices) and CsO₁₂ icosahedra.     

Molecular structures of chalcone podands: A prognosis of photoinduced transformations in the crystals

A series of chalcone podands with the propenone group in the ortho position of the bridging aryl substituent with respect to the oxyethylene fragment is synthesized. The influence of the preorganization of the chalcone podand molecules in crystals on their ability to participate in topochemical reactions is investigated. From analyzing the X-ray structural data, the highest probability of the solid-state photochemical [2 + 2]cycloaddition is predicted for podands with phenyl substituents and the oxyethylene fragment containing two or three oxygen atoms. The X-ray structural data for the chalcone podand C₃₂H₂₆O₄ (3a) are as follows: a = 7.904(9) Å, b = 14.92(2) Å, c = 21.30(3) Å, β = 91.7(1)°, monoclinic system, space group P2₁/c, Z = 4, V = 2510(5) ų, ρ = 1.26 g/cm³, and R = 0.046; C₃₄H₃₀O₅ (3b): a = 15.738(9) Å, b = 11.889(2) Å, c = 15.0830(15) Å, β = 105.47(14)°, monoclinic system, space group C2/c, Z = 4, V = 2720.0(9) ų, ρ = 1.266 g/cm³, and R = 0.0418; C₃₂H₂₄N₂O₈ (4a): a = 17.9416(18) Å, b = 10.9703(8) Å, c = 41.699(2) Å, β = 105.970(11)°, monoclinic system, space group P2₁/c, Z = 4, V = 2781.4(5) ų, ρ = 1.348 g/cm³, and R = 0.0426; C₃₆H₃₂N₂O₁₀ (4c): a = 7.6286(5)Å, b = 17.9398(10) Å, c = 11.5890(3)Å, β = 95.287(4)°, monoclinic system, space group P2₁/n, Z = 2, V = 1579.27(14) ų, ρ = 1.372 g/cm³, and R = 0.0377; and C₂₈H₂₂O₆ (5a): a = 15.6032(10) Å, b = 8.1131(5) Å, c = 17.7334(11) Å, β = 91.381(5)°, monoclinic system, space group C2/c, Z = 4, V = 2244.2(2) ų, ρ = 1.345 g/cm³, and R = 0.0309.     

Synthesis and crystal structure of tripeptide fragment of elastin

Boc-Gly-Val-Pro-OBzl, a protected tripeptide fragment of repeating sequences of mammalian elastic protein elastin was synthesized and characterized by X-ray diffraction method. The sequence C₂₄ H₃₅ N₃ O₆ crystallizes in the orthorhombic space group P2₁2₁2₁ with the parameters a = 9.4700(11) Å, b = 9.8980(8) Å, c = 26.721(3) Å, V = 2504.7(4) ų and Z = 4. The final residual factor is 0.0670. The structure exhibits intra and intermolecular hydrogen bonds.     

Crystal structures of complexes of the <Emphasis Type="Italic">cys-syn-cys</Emphasis> isomer of dicyclohexano-18-crown-6 with oxonium hexafluorotantalate and oxonium hexafluoroniobate

The crystal structures of [(cys-syn-cys-dicyclohexano-18-crown-6 · H₃O)][TaF₆] and [(cys-syn-cys-dicyclohexano-18-crown-6 · H₃O)][NbF₆] complex compounds are determined using X-ray diffraction analysis. The tantalum complex has two polymorphic modifications, namely, the monoclinic (I) and triclinic (II) modifications. The unit cell parameters of these compounds are as follows: a = 8.507(4) Å, b = 11.947(5) Å, c = 27.392(12) Å, β = 93.11(1)°, Z = 4, and space group P2₁/n for modification I; and a = 10.828(1) Å, b = 11.204(1) Å, c = 12.378(1) Å, α = 72.12(1)°, β = 79.40(1)°, γ = 73.70(1)°, Z = 2, and space group P-1 for modification II. The triclinic niobium complex [(cys-syn-cys-dicyclohexano-18-crown-6 · H₃O)][NbF₆] (III) with the unit cell parameters a = 10.796(3) Å, b = 11.183(3) Å, c = 12.352(3) Å, α = 72.364(5)°, β = 79.577(5)°, γ = 73.773(4)°, Z = 2, and space group P-1 is isostructural with tantalum complex II. The structures of all three complexes are ionic in character. The oxonium cation in complexes I–III is encapsulated by the crown ether and thus forms one ordinary and two bifurcated hydrogen bonds with the oxygen atoms of the crown ether. This macrocyclic cation is bound to the anions through the C-H...F contacts (H...F, 2.48–2.58 Å). The conformation of the macrocycle in complex I differs substantially from that in complex II (III).     

Synthesis,thermal analysis,and crystal structure of manganese(II) 9-molybdocobaltate(III)

Manganese(II) 9-molybdocobaltate(III) of the composition [Mn(H₂O)₄] · [CoMo₉O₂₇(OH)₅] · 7H₂O (I) has been synthesized for the first time and investigated using X-ray diffraction and thermal gravimetric analyses. Compound I crystallizes in the trigonal system with the following unit cell parameters: a = 15.926(1) Å, c = 12.363(1) Å, V = 2715.6(4) ų, M = 1692.55, Z = 3, ρ_(calcd) = 3.105 g/cm³, space group R32.     

X-ray mapping in heterocyclic design: XII. X-ray diffraction study of 2-pyridones containing cycloalkane fragments annelated to the C(5)-C(6) bond

The structures of 4,6-dimethyl-1H-pyridin-2-one [a = 6.125(2) Å, b = 15.153(4) Å, and c = 14.477(4) Å, Z = 8, space group Pbca], the 2: 1: 1 complex of 4-methyl-1,5,6,7-tetrahydro-2H-cyclopenta[b]pyridin-2-one with phosphoric acid and methanol [a = 11.181(2) Å, b = 14.059(6) Å, c = 13.593(4) Å, β = 97.78(2)°, Z = 8, space group P2₁/n], 4-methyl-1,5,6,7,8,9-hexahydro-2H-cyclohepta[b]pyridin-2-one [a = 12.565(6) Å, b = 5.836(6) Å, c = 13.007(3) Å, β = 93.10(3)°, Z = 4, space group P2₁/n], and 4-methyl-5,6,7,8,9,10-hexahydrocycloocta[b]pyridin-2(1H)-one [a = 12.955(3) Å, b = 6.1595(15) Å, c = 13.038(3) Å, β = 95.50(2)°, Z = 4, space group P2₁/n] are determined by single-crystal X-ray diffraction. The structures are solved by direct methods and refined by the full-matrix least-squares procedure in the anisotropic approximation to R = 0.0755, 0.0644, 0.0754, and 0.0569, respectively. The structures of 4-methyl-1,5,6,7-tetrahydro-2H-cyclopenta[b]pyridin-2-one [a = 7.353(4) Å, b = 8.176(4) Å, c = 13.00(1) Å, β = 105.64(2)°, Z = 4, space group P2₁/c] and 2-oxo-1,2,5,6,7,8-hexahydroquinoline-3-carbonitrile [a = 5.9870(2) Å, b = 16.5280(5) Å, c = 9.6540(3) Å, β = 111.52(4)°, Z = 4, space group P2₁/c] are studied by the powder diffraction technique. The structures are solved using the grid search procedure and refined by the Rietveld method to R _wp = 0.108 and 0.058, R_exp = 0.032 and 0.027, R _p = 0.076 and 0.043, R _b = 0.123 and 0.077, and χ² = 7.9 and 3.64, respectively. In all the structures, hydrogen bonds involving the N, H, and O atoms of the pyridone fragment are formed.     

Crystal structure of <Emphasis Type="Italic">p</Emphasis>-carboxyphenylhydrazone benzoylacetone

The crystal structure of p-carboxyphenylhydrazone benzoylacetone is determined. The crystals are monoclinic, a = 13.614(4) Å, b = 11.388(2) Å, c = 20.029(6) Å, β = 104.82(2)°, V = 2339(9) ų, Z = 8, space group C2/c, and R = 0.038 for 1622 reflections with I > 2σ(I). The crystal is built of C₁₇H₁₄N₂O₄ neutral molecules that are linked by O-H?O hydrogen bonds between the carboxyl groups into centrosymmetric pseudodimers. The effect of carboxylation of the phenylhydrazone fragment and the position of the carboxyl group on the molecular packing in the crystal is determined. The N(1)-H(1N)?O(1) intramolecular hydrogen bond (N-H, 0.94 Å; H?O, 1.87 Å; N?O, 2.59 Å; and the N-H?O angle, 133°) is formed in the molecule.     

Synthesis and crystal structure of 2-acetylnaphthalen-6-yl 4-methylbenzosulfonate

The title compound has been synthesized by the reaction of 1-(6-hydroxy-2-naphthyl)-1-ethanone (2) with p-toluenesulfonyl chloride. Its structure was determined by single crystal X-ray diffraction. 2-Acetylnaphthalen-6-yl 4-methylbenzosulfonate (3) crystallizes in the orthorhombic space group Pbca with a = 12.727(3) Å, b = 14.560 (3) Å, c = 17.688 (4) Å, V = 3277.8 (11) ų, and Z = 8. The results demonstrate that the dihedral angle between the benzene ring and the naphthalene ring is 116.5^°, and the length (1.417 Å) of single C–O bond of 3 is longer than that of single C–O bond in the relative compounds.     

Crystal structure of 2,4,6-trinitropyridine and its N-oxide

The structures of 2,4,6-trinitropyridine (TNPy) and its N-oxide were determined by X-ray single crystal diffraction. TNPy and 2,4,6-trinitropyridine-1-oxide (TNPyO) crystallize in space groupPbcn andPnma, respectively. The crystallographic parameters are as follows: TNPy,a = 28.573(6) Å,b = 9.7394(19) Å, andc = 8.7566(18) Å, α = β = γ = 90^°, μ = 0.164 mm^?1,V = 2436.8(8) ų,z = 12,Dx = 1.751 mg/mm³,F(000) = 1296,T = 293(2) K, 1.43^°≤ θ≤ 27.40^°, the finalR factor:R ₁ = 0.0574,wR ₂ = 0.1337. TNPyO,a = 9.6272(19) Å,b = 14.128(3) Å, andc = 5.9943(12) Å, α = β = γ = 90^°, μ = 0.179 mm^?1,V = 815.3(3)ų,z = 4,Dx = 1.875 mg/mm³,F(000) = 464,T = 293(2) K, 2.88^°≤ θ≤ 27.44^°, the finalR factor:R ₁ = 0.0497,wR ₂ = 0.1515.     

X-ray mapping in heterocyclic design: XIV. Tricyclic heterocycles based on 2-Oxo-1,2,5,6,7,8-hexahydroquinoline-3-carbonitrile

The structures of four compounds are studied using single-crystal X-ray diffraction: 1-[2-(4-chlorophenyl)-2-oxoethyl]-2-oxo-1,2,5,6,7,8-hexahydroquinoline-3-carbonitrile [a = 4.908(4) Å, b = 11.644(10) Å, c = 13.587(2) Å, β = 94.31(5)°, Z = 2, space group P2₁]; 2-[2-(4-chlorophenyl)-2-oxoethoxy]-5,6,7,8-tetrahydroquinoline-3-carbonitrile [a = 7.6142(8) Å, b = 14.778(2) Å, c = 14.132(2) Å, β = 100.38(1)°, Z = 4, space group P2₁/c]; 4-(aminocarbonyl)-2-(chlorophenyl)-6,7,8,9-tetrahydro[1.3]oxazolo[3,2-a]quinolin-3-ium per-chlorate [a = 5.589(7) Å, b = 24.724(15) Å, c = 13.727(5) Å, β = 97.66(9)°, Z = 4, space group P2₁/n]; and (3-amino-5,6,7,8-tetrahydrofuro[2,3-b]quinolin-2-yl)-(4-chlorophenyl) methanone [a = 7.150(2) Å, b = 7.4288(10) Å, c = 15.314(3) Å, α = 98.030(10)°, β = 99.21(2)°, γ = 105.34(2)°, Z = 2, space group \(P\bar 1\)]. The structures are solved by direct methods and refined by the full-matrix least-squares procedure in the anisotropic approximation to R = 0.0728, 0.0439, 0.1228, and 0.0541, respectively. The structure of 1-(4-chlorophenyl)-4-piperidin-1-yl-8,9-dihydro-7H-pyrrolo[3.2.1-ij]quinoline-5-carboxamide [a = 23.9895(9) Å, b = 5.1557(3) Å, c = 17.0959(9) Å, β = 106.43°, Z = 4, space group P ₁/c] is investigated by X-ray powder diffraction. This structure is solved using the grid search procedure and refined by the Rietveld method to R _wp = 0.0773, R _exp = 0.0540, R _p = 0.0585, R _b = 0.1107, and χ ² = 1.78.     

X-ray mapping in heterocyclic design: XV. Tricyclic heterocycles based on 2-oxo-2,5,6,7-tetrahydro-1<Emphasis Type="Italic">H</Emphasis>-cyclopenta[<Emphasis Type="Italic">b</Emphasis>]pyridine-3-carbonitrile

The structures of five compounds are studied using single-crystal X-ray diffraction: 2-oxo-2,5,6,7-tetrahydro-1H-cyclopenta[b]pyridine-3-carbonitrile [a = 15.641(8) Å, b = 9.373(5) Å, c = 7.387(4) Å, β = 92.91(5)°, Z = 4, space group P2₁/c]; 1-[2-(4-chlorophenyl)-2-oxoethyl]-2-oxo-2,5,6,7-tetrahydro-1H-cyclopenta[b]pyridine-3-carbonitrile [a = 4.728(4) Å, b = 28.035(11) Å, c = 11.184(3) Å, Z = 4, space group P2₁2₁2₁]; 2-[2-(4-chlorophenyl)-2-oxoethoxy]-6,7-dihydro-5H-cyclopenta[b]pyridine-3-carbonitrile [a = 10.1202(13) Å, b = 11.2484(18) Å, c = 13.4323(19) Å, β = 102.05(1)°, Z = 4, space group P2₁/c]; 2-(4-chlorophenyl)-3a, 6,7,8-tetrahydrocyclopenta[e][1.3]oxazolo[3.2-a]pyridine-4-carboxamide perchlorate [a = 7.702(2) Å, b = 9.599(3) Å, c = 23.798(5) Å, β = 93.44(2)°, Z = 4, space group P2₁/c]; and (3-amino-6,7-dihydro-5H-cyclopenta[b]furo[3.2-e]pyridin-2-yl)(4-chlorophenyl)methanone [a = 7.3273(2) Å, b = 13.390(3) Å, c = 28.792(8) Å, Z = 8, space group Pbca]. The structures are solved using direct methods and refined by the full-matrix least-squares procedure in the anisotropic approximation to R = 0.0580, 0.0724, 0.0469, 0.0477, and 0.0418, respectively.     

On the structural basis of the presence of two optical axes in α-HIO<Subscript>3</Subscript> crystal

An X-ray diffraction study of α-HIO₃ crystal has been performed with the following results: sp. gr. P2₁2₁2₁, Z = 4, a = 5.5360(3) Å, b = 5.8723(6) Å, c = 7.7291(5) Å, and R factors R(F)/wR(F) = 0.86/0.69%. Disordering of iodine site is revealed, which is described in terms of anharmonic atomic displacements. Packing (likely unique) of all structure atoms over two systems of planes rotated by an angle close to the rotation of optical axes (47°) is revealed. The rotation of the plane of polarization of light based on the structural data is calculated for the first time for the α-HIO₃ crystal.     

Crystal structure of new micalike titanosilicate—bussenite,Na<Subscript>2</Subscript>Ba<Subscript>2</Subscript>Fe<Superscript>2+</Superscript>[TiSi<Subscript>2</Subscript>O<Subscript>7</Subscript>][CO<Subscript>3</Subscript>]O(OH)(H<Subscript>2</Subscript>O)F

The crystal structure of mineral bussenite, Na₂Ba₂Fe[TiSi₂O₇][CO₃]O(OH)(H₂O)F, found in the Khibiny massif (the Kola Peninsula) has been determined. The parameters of the triclinic unit-cell are a = 5.399(3) Å, b = 7.016(9) Å, c = 16.254(14) Å, α = 102.44(8)°, β = 93.18(6)°, γ = 90.10(7)°, sp. gr. \(P\bar 1\), R = 0.054 for 1418 reflections with |F| > 2.5σ(F). The mineral studied belongs to the family of layered titanosilicates, in which, unlike the sulfate-and phosphate-containing representatives of this family, the interlayer spaces are filled with carbonate groups.